Vista City Council
August 11, 2026

MSCP Narrow Endemic (NE)
Narrow endemic species are native species that have "restricted geographic distributions, soil affinities, and/or habitats." The MSCP participants' subarea plans have specific conservation measures to ensure impacts to narrow endemics are avoided to the maximum extent practicable.

HELIX
Environmental Planning
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Appendix C
Cultural Resources Survey Report
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CULTURAL RESOURCES SURVEY REPORT

FOR THE WEST BOBIER DRIVE PROJECT

CITY OF VISTA, CALIFORNIA
APN 161-030-07
Submitted to:

City of Vista
200 Civic Center Drive
Vista, California 92084
Prepared for:

SWS Engineering
1635 Lake San Marcos, Suite 200
San Marcos, California 92078
Prepared by:

BFSA Environmental Services,
a Perennial Company
14010 Poway Road, Suite A
Poway, California 92064
September 13, 2024
o 3)
BFSA Environmental Services
A Perennial Company
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Cultural Resources Survey Report for the West Bobier Drive Project Archaeological Database Information
Author: Andrew J. Garrison, M.A., RPA
Consulting Firm:

BFSA Environmental Services,
a Perennial Company
14010 Poway Road, Suite A
Poway, California 92064
(858) 484-0915
Report Date: September 13, 2024
Report Title: Cultural Resources Survey Report for the West Bobier Drive Project, City of Vista, California (APN 161-030-07)
Prepared .for: SWS Engineering
1635 Lake San Marcos, Suite 200
San Marcos, California 92078
Submitted to:

BFSA Environmental Services,
a Perennial Company
14010 Poway Road, Suite A
Poway, California 92064
USGS Quadrangle: Section 33, Township 11 South, Range 4 West of the San Luis Rey, California (7.5 -minute) Quadrangle
Study Area: Approximately 1.7 acres
Key Words:

Archaeological survey; USGS San Luis Rey, California
Quadrangle (7.5 -minute); Site SDI -5345; not CRHR-eligible; monitoring of grading recommended.
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Cultural Resources Sun'ey Report for the West Bobier Drive Project Table of Contents
Pate

1.0 MANAGEMENT SUMMARY/ABSTRACT 1.0-1

2.0 INTRODUCTION 2.0-1

3.0 PROJECT SETTING 3.0-1

3.1 Natural Setting 3.0-1

3.1.1 Geology 3.0-1

3.1.2 Biology 3.0-1

3.2 Cultural Setting 3.0-2

3.2.1 Paleoenvironment 3.0-2

3.2.2 Prehistory 3.0-3

3.2.3 History 3.0-5

3.2.4 General History of the City of Vista 3.0-7

4.0 METHODOLOGY 4.0-1

4.1 Archaeological Records Search 4.0-1

4.2 Field Methodology 4.0-1

4.3 Report Preparation and Recordation 4.0-1

4.4 Native American Consultation 4.0-2

4.5 Applicable Regulations 4.0-2

4.5.1 California Environmental Quality Act 4.0-2

5.0 RESULTS 5.0-1

5.1 Records Search Results 5.0-1

5.2 Field Investigation 5.0-3

6.0 MANAGEMENT CONSIDERATIONS/RECOMMENDATIONS 6.0-1

7.0 PERSONNEL 7.0-1

8.0 CERTIFICATION 8.0-1

9.0 REFERENCES CITED 9.0-1
Appendices
Appendix A — Resumes of Key Personnel
Appendix B — Site Record Form Update
Appendix C — Archaeological Records Search Results*
Appendix D — NAHC Sacred Lands File Search Results*
Appendix E — Confidential Maps*
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Cultural Resources Survey Report for the West Bobier Drive Project List of Figures
Figure Page
Figure 2.0-1 General Location Map 2.0-2
Figure 2.0-2 Project Location Map 2.0-3
Figure 2.0-3 Project Development Map 2.0-4
Figure 5.2-1 Cultural Resource Location Map* 5.0-9
Figure 5.2-2 Feature Location Map* 5.0-10
Figure 6.0-1 Site SDI -5345 on Project Development Map* 6.0-2 *Deleted for public review and bound separately in the Confidential Appendix List of Plates
Plate Page
Plate 5.2-1 Overview of the subject property, facing north 5.0-4 Plate 5.2-2 Overview of the subject property, facing south 5.0-4 Plate 5.2-3 Overview of the subject property, facing northwest 5.0-5 Plate 5.2-4 Overview of the remnant driveway, facing northeast 5.0-5 Plate 5.2-5 Overview of BMF 1, facing northwest 5.0-6
Plate 5.2-6 Closeup of BMF 1, facing west 5.0-7
Plate 5.2-7 Overview of BMF 2, facing northeast 5.0-7
Plate 5.2-8 Closeup of BMF 2, facing northeast 5.0-8
List of Tables
Table Page
Table 5.1-1 Previously Recorded Cultural Resources Within a One -Half -Mile Radius of the Project 5.0-1
Table 51-2 Archaeological Studies Mapped by the SCIC Overlapping the Project 5.0-2 08/11/2026
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Cultural Resources Survey Report for the West Bobier Drive Project

1.0 MANAGEMENT SUMMARY/ABSTRACT
In response to a request from the applicant, BFSA Environmental Services, a Perennial Company (BFSA), conducted a Phase I cultural resources survey of the West Bobier Drive Project in the city of Vista, San Diego County, California. The assessment was conducted as part of the environmental clearance required for the proposed grading associated with the residential subdivision of Assessor's Parcel Number (APN) 161-030-07. The evaluation program was conducted in accordance with the California Environmental Quality Act (CEQA), Section 15064.5, and the City of Vista's cultural resource guidelines to determine the presence of any archaeological or historic resources that would be affected by the proposed project and whether these resources meet the eligibility requirements for the California Register of Historical Resources (CRHR).

A records search was reviewed from the South Coastal Information Center (SCIC) at San Diego State University (SDSU) to identify previously discovered archaeological sites in the project area, and a Sacred Lands File (SLF) search was requested from the Native American Heritage Commission (NAHC) to list potentially sacred or ceremonial sites or landforms on or near the project. The SCIC records search identified one previously recorded resource within the property (prehistoric bedrock milling site SDI -5345). Site SDI -5345 was originally recorded within what is now West Bobier Drive, as well as on the north and south side of the current street alignment.

In 1978, Site SDI -5345 was subjected to testing and found not eligible for the CRHR and most of the previously recorded bedrock milling features have destroyed by development (Chace 1978; Giletti and Robbins -Wade 2008; Robbins -Wade and Giletti 2013).

BFSA Director of Field Operations Clarence L. Hoff, under the direction of Principal Investigator Tracy A. Stropes, M.A., RPA, conducted the archaeological survey of the project on August 27, 2024. During the survey, signs of the past development and clearing of the property were noted, while ground visibility was at times limited by vegetation and past disturbances.

Previously, the property had contained two structures, likely a residence and an ancillary structure.

Both structures were removed between 2008 and 2009. No new cultural resources or any artifacts associated with Site SDI -5345 were identified during the survey. Two previously recorded bedrock milling features (BMF 1 and BMF 2) associated with Site SDI -5345 were located within the subject property. No associated artifacts were observed, and prior testing and evaluation have already determined that the site is not eligible for the CRHR. Therefore, the resource is not considered a Historical Resource under CEQA criteria and impacts associated with the proposed project are not considered significant. Although Site SDI -5345 is not eligible for the CRHR, due to prior impacts to the property, and because the ground visibility was, at times, limited during the survey, it is recommended that the project be conditioned with archaeological and Native American monitoring during grading of the subject property. A copy of this report will be permanently filed with the SCIC at SDSU. All notes and other materials related to this project will be curated at the BFSA archaeological laboratory in Poway, California.

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Cultural Resources Survey Report for the West Bobier Drive Project

2.0 INTRODUCTION
BFSA conducted the Phase I cultural resources survey for the West Bobier Drive Project in response to a requirement by the City of Vista for an environmental assessment of a proposed residential development in conformance with CEQA and the City's environmental guidelines. The project is located southeast of the intersection of West Bobier Drive and Sports Park Way, within the city of Vista, San Diego County, California (Figure 2.0-1). The proposed project includes the development of an approximately 1.7 -acre property (APN 161-030-07) located within Section 13, Township 11 South, Range 4 West of the San Bernardino Base and Meridian, as shown on the United States Geological Survey (USGS) San Luis Rey, California (7.5 -minute) topographic quadrangle (Figure 2.0-2). The proposed project includes the grading of the subject property for a residential development, along with associated infrastructure (Figure 2.0-3).

The decision to request this investigation was based upon the cultural resource sensitivity of the locality, as suggested by known site density and predictive modeling. Sensitivity for cultural resources in a given area is usually indicated by known settlement patterns, which, in the San Diego County area, are focused around freshwater resources and a food supply. An archaeological records search for the project was conducted at the SCIC at SDSU. The records search identified one previously recorded resource within the property (prehistoric bedrock milling site SDI -5345).

Site SDI -5345 was originally recorded within what is now West Bobier Drive as well on the north and south side of the current street alignment. The records search also identified four previous studies overlapping the subject property (Chace 1978, Marben-Laird Associates 1987; Rosenberg et al. 2007; Giletti and Robbins -Wade 2008). As a result, Site SDI -5345 has been subjected to previous testing and found not eligible for the CRHR, with most of the previously recorded bedrock milling features being destroyed by development (Chace 1978, Giletti and Robbins -Wade 2008; Robbins -Wade and Giletti 2013). The records search results are discussed in detail in Section 5.1.

Principal Investigator Tracy A. Stropes, M.A., RPA, directed the cultural resources study for the project. On August 27, 2024, Clarence L. Hoff, BFSA Director of Field Operations, conducted the survey. The survey was conducted in 10 -meter interval transects. No previously unidentified resources were identified during the survey. Two bedrock milling features associated with Site SDI -5345, and previously documented by Giletti and Robbins -Wade (2008), were located within the property. However, no associated artifacts were identified and the site has already been evaluated as not CRHR-eligible.

Project Archaeologist Andrew J. Garrison, M.A., RPA, prepared the technical report.

Emily T. Soong developed the graphics and Shawna M. Krystek conducted technical editing and report production. Qualifications of key personnel are provided in Appendix A.

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General Location Map
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Figure 2.0-2
Project Location Map
The West Bobier Drive Project
USGS San Luis Rey and San Marcos Quadrangles (7.5 -minute series) 08/11/2026

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Cultural Resources Survey Report for the West Bobier Drive Project

3.0 PROJECT SETTING
The project setting includes the physical context of the project, as well as the cultural setting of prehistoric and historic human activities in the general area.

3.1 Natural Setting
The project area lies within the city of Vista, located approximately 2.5 miles south of the San Luis Rey River and approximately 1.75 miles north of Buena Vista Creek. The San Luis Rey River flows southwest to the Pacific Ocean while the Buena Vista Creek flows westward to the estuarine Buena Vista Lagoon. The lagoon was formed as the sea level rose rapidly following the last glacial sequence, which corresponds to a long period of lower sea levels that allowed Buena Vista Creek to cut a deep canyon along the drainage. The lagoon provided a variety of marine food resources that were used prehistorically in the subsistence routine of Late Prehistoric Luisefio groups and earlier La Jolla Complex peoples (Rosenberg et al. 2007).

The property consists primarily of a small knoll which slopes gently towards the south.

The elevation of the subject property ranges from 466 feet above mean sea level (AMSL) along the northern boundary to 450 feet AMSL in the southwestern corner. The soil type found within the project consists of Diablo clay, 2 to 9 percent slopes (DaC) (NRCS 2024). The northern portion of the property contains large granitic outcroppings. Formerly, the subject property contained a residence and ancillary structure, and the property has been previously cleared and partially graded. As such, vegetation within the project primarily consists of non-native weeds, grasses, and trees.

3.1.1 Geology
San Diego County lies in the Peninsular Ranges Geomorphic Province of southern California, a geologic unit that extends from the southern Los Angeles Basin south to the tip of Baja California. Extensive Cretaceous and minor Jurassic igneous rocks dominate the Peninsular Ranges. Post -Cretaceous rocks consist of volcanic, marine, and nonmarine sediments (Norris and Webb 1990). The mountainous zone, which lies in a northwest to southeast trend through the county, extends to 6,533 feet AMSL (Beauchamp 1986). Foothills and valleys, known as the cismontane, extend west from the mountains. A coastal plain occupies the western portion of San Diego County and is characterized by a sequence of marine and nonmarine sedimentary rocks in a mesa formation (Demere and Walsh 1993). That coastal mesa region is cut by several large drainages originating in the mountains and foothills. Large bays and lagoons characterize the coastal zone where the major drainages empty into the sea. The portion of the mesas that terminate at the ocean form intervening bluffs (Beauchamp 1986).

3.1.2 Biology
Rainfall is one of the most important factors, along with soils, that control the development of plant regimes along the western side of the Peninsular Ranges. This semi -arid Mediterranean

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Cultural Resources Survey Report for the West Bobier Drive Project climate has developed vegetative communities in response to differing rainfall amounts and soil types. Cismontane regions typically receive more rainfall than coastal mesas due to the orographic effect upon the predominately east -moving moist air. Coastal sage scrub is the dominant community near the coast, while the plant community grades to oak woodland in the upper cismontane. Drainages exhibit riparian woodland environments, particularly where the slope is gentle and soil has accumulated.

3.2 Cultural Setting
The project is located approximately 2.5 miles south of the San Luis Rey River and approximately 1.75 miles north of Buena Vista Creek. The San Luis Rey River, Buena Vista Creek, and Buena Vista Lagoon provided a rich and varied food resource that was less subject to the debilitating effects of limited seasonal rainfall than the inland areas of San Diego County. At the time of the first European colonization (1769), and for a period of time thereafter, Native American people used resources from the bay and adjacent wetland areas (Gallegos and Kyle 1988).

The cultures that have been identified in the general vicinity of the project consist of a possible Paleo Indian manifestation of the San Dieguito Complex, the Archaic and Early Milling Stone horizons represented by the La Jolla Complex, and the Late Prehistoric Kumeyaay culture.

The area was used for ranching and farming following the Hispanic intrusion into the region and extending into the historic period. A brief discussion of the cultural elements within the project is provided below.

3.2.1 Paleoenvironment
Because of the close relationship between prehistoric settlement and subsistence patterns and the environment, it is necessary to understand the setting in which these systems operated. At the end of the final period of glaciation, approximately 10,000 to 11,000 years before the present (YBP), the sea level was considerably lower than it is now; the coastline at that time would have been two to two and a half miles west of its present location (Smith and Moriarty 1985a, 1985b).

At approximately 7,000 YBP, the sea level rose rapidly, filling in many coastal canyons that had been dry during the glacial period. The period between 7,000 and 4,000 YBP was characterized by conditions that were drier and warmer than they were previously, followed by a cooler, moister environment similar to the present-day climate (Robbins -Wade 1990). Changes in sea level and coastal topography are often manifested in archaeological sites through the types of shellfish that were utilized by prehistoric groups. Different species of shellfish prefer certain types of environments, and dated sites that contain shellfish remains reflect the setting that was exploited by the prehistoric occupants.

Unfortunately, pollen studies have not been conducted for this area of San Diego; however, studies in other areas of southern California, such as Santa Barbara, indicate that the coastal plains supported a pine forest between approximately 12,000 and 8,000 YBP (Robbins -Wade 1990).

After 8,000 YBP, this environment was replaced by more open habitats, which supported oak and

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Cultural Resources Survey Report for the West Bobier Drive Project non -arboreal communities. The present coastal sage scrub and chaparral environments appear to have become dominant after 2,200 YBP (Robbins -Wade 1990).

3.2.2 Prehistory
In general, the prehistoric record of San Diego County has been documented in many reports and studies, several of which represent the earliest scientific works concerning the recognition and interpretation of the archaeological manifestations present in this region.

Geographer Malcolm Rogers initiated the recordation of sites in the area in the 1920s and 1930s, using his field notes to construct the first cultural sequences based upon artifact assemblages and stratigraphy (Rogers 1966). Subsequent scholars expanded the information gathered by Rogers and offered more academic interpretations of the prehistoric record. Moriarty (1966, 1967, 1969), Warren (1964, 1966), and True (1958, 1966) all produced seminal works that critically defined the various prehistoric cultural phenomena present in this region (Moratto 1984). Additional studies have sought to further refine these earlier works (Cardenas 1986; Moratto 1984; Moriarty 1966, 1967; True 1970, 1980, 1986; True and Beemer 1982; True and Pankey 1985; Waugh 1986).

In sharp contrast, the current trend in San Diego prehistory has resulted in a revisionist group that rejects the established cultural, historical sequence for San Diego (Warren et al. 1998), replacing the concepts of La Jolla, San Dieguito, and all of their other manifestations with an extensive, all -encompassing, chronologically undifferentiated cultural unit that ranges from the initial occupation of southern California to around A.D. 1000 (Bull 1983, 1987; Ezell 1983, 1987; Gallegos 1987; Kyle et al. 1990; Stropes 2007). For the present study, the prehistory of the region is divided into four major periods: Early Man, Paleo Indian, Early Archaic, and Late Prehistoric.

Early Man Period (Prior to 8500 B.C.)
At the present time, there has been no concrete archaeological evidence to support the occupation of San Diego County prior to 10,500 YBP. Some archaeologists, such as Carter (1957, 1980) and Minshall (1976), have been proponents of Native American occupation of the region as early as 100,000 years ago. However, their evidence for such claims is sparse at best and they have lost much support over the years as more precise dating techniques have become available for skeletal remains thought to represent early man in San Diego. In addition, many of the "artifacts" initially identified as products of early man in the region have since been rejected as natural products of geologic activity. Some of the local proposed Early Man Period sites include Texas Street, Buchanan Canyon, Brown, Mission Valley (San Diego River Valley), Del Mar, and La Jolla (Bada et al. 1974; Carter 1957, 1980; Minshall 1976, 1989; Moriarty and Minshall 1972; Reeves 1985; Reeves et al. 1986).

Paleo Indian Period (8500 to 6000 B.C.)
For the region, it is generally accepted that the earliest identifiable culture in the archaeological record is represented by the material remains of the Paleo Indian Period San Dieguito Complex. The San Dieguito Complex was thought to represent the remains of a group

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Cultural Resources Survey Report for the West Bobier Drive Project of people who occupied sites in this region between 10,500 and 8,000 YBP, and who were related to or contemporaneous with groups in the Great Basin. As of yet, no absolute dates have been forthcoming to support the antiquity attributed to this cultural phase. The artifacts recovered from San Dieguito Complex sites duplicate the typology attributed to the Western Pluvial Lakes Tradition (Moratto 1984; Davis et al. 1969). These artifacts generally include scrapers, choppers, large bifaces, and large projectile points, with few milling tools. Tools recovered from San Dieguito Complex sites, along with the general pattern of their site locations, led early researchers to believe that the people of the San Dieguito Complex were a wandering hunter/gatherer society (Moriarty 1969; Rogers 1966).

The San Dieguito Complex is the least understood of the cultures that have inhabited the San Diego County region. This is due to an overall lack of stratigraphic information and/or datable materials recovered from sites identified as belonging to the San Dieguito Complex. Currently, controversy exists among researchers regarding the relationship of the San Dieguito Complex and the subsequent cultural manifestation in the area, the La Jolla Complex. Although, firm evidence has not been recovered to indicate whether the San Dieguito Complex "evolved" into the La Jolla Complex, the people of the La Jolla Complex moved into the area and assimilated with the people of the San Dieguito Complex, or the people of the San Dieguito Complex retreated from the area because of environmental or cultural pressures.

Early Archaic Period (6000 B.C. to A.D. 0)
Based upon evidence suggesting climatic shifts and archaeologically observable changes in subsistence strategies, a new cultural pattern is believed to have emerged in the San Diego region around 6000 B.C. Archaeologists believe that this Archaic Period evolved from or replaced the San Dieguito Complex culture, resulting in a pattern referred to as the Encinitas Tradition. In San Diego, the Encinitas Tradition is believed to be represented by the coastal La Jolla Complex and its inland manifestation, the Pauma Complex. The La Jolla Complex is best recognized for its pattern of shell middens and grinding tools closely associated with marine resources and flexed burials (Shumway et al. 1961; Smith and Moriarty 1985a). Increasing numbers of inland sites have been identified as dating to the Archaic Period, focusing upon terrestrial subsistence (Cardenas 1986; Smith 1996; Raven -Jennings and Smith 1999a, 1999b).

The tool typology of the La Jolla Complex displays a wide range of sophistication in the lithic manufacturing techniques used to create the tools found at their sites. Scrapers, the dominant flaked tool type, were created by either splitting cobbles or by finely flaking quarried material.

Evidence suggests that after about 8,200 YBP, milling tools began to appear in La Jolla Complex sites. Inland sites of the Encinitas Tradition (Pauma Complex) exhibit a reduced quantity of marine -related food refuse and contain large quantities of milling tools and food bone. The lithic tool assemblage shifts slightly to encompass the procurement and processing of terrestrial resources, suggesting seasonal migration from the coast to the inland valleys (Smith 1996). At the present time, the transition from the Archaic Period to the Late Prehistoric Period is not well

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Cultural Resources Survey Report for the West Bobier Drive Project understood. Many questions remain concerning the cultural transformation between periods, possibilities of ethnic replacement, and/or a possible hiatus from the western portion of the county.

Late Prehistoric Period (A.D. 0 to 1769)
A group of incoming Shoshonean people with a language belonging to the Uto-Aztecan linguistic group settled in the southern California area approximately 2,500 to 2,000 YBP (King 1982). In San Diego County, these people became known as the Luiseno Indians because of their association with the San Luis Rey Mission during the early historic period (Moratto 1984). Their neighbors to the south, the Yuman -speaking Kumeyaay, were known as the Diegueno due to their residence near Mission Basilica San Diego de Alcala. The geographic boundary in pre- and proto- historic times between the Luiseno and Diegueno is difficult to place due to the similarity of their tool kits and settlement patterns. Attempts have been made to differentiate between the two based upon archaeological assemblages; however, further investigation is necessary (True 1966).

The Luiseno people were hunter/gatherers with a seasonal migration, which included both the coastal and inland areas in their range. The annual round included hunting terrestrial game and gathering plant foods when available. Diet was augmented with marine resources during seasonal visits to the coast.

3.2.3 History
Exploration Period (1530 to 1769)
The historic period around San Diego Bay began with the landing of Juan Rodriguez Cabrillo and his men in 1542 (Chapman 1921). Sixty years after the Cabrillo expeditions (1602 to 1603), Sebastian Vizcaino made an extensive and thorough exploration of the Pacific coast.

Although the voyage did not extend beyond the northern limits of the Cabrillo track, Vizcaino had the most lasting effect upon the nomenclature of the coast. Many of his assigned place names have survived, whereas nearly every one of Cabrillo's has faded from use. Cabrillo named the first (now) United States port "San Miguel"; 60 years later, Vizcaino changed it to "San Diego" (Rolle 1969).

Spanish Colonial Period (1769 to 1821)
The Spanish occupation of the claimed territory of Alta California took place during the reign of King Carlos III of Spain (Engelhardt 1920). Jose de Galvez, a powerful representative of the king in Mexico, conceived the plan to colonize Alta California and thereby secure the area for the Spanish (Rolle 1969). The effort involved military and religious components, where the overall intent of establishing forts and missions was to gain control of the land and the native inhabitants through conversion. Actual colonization of the San Diego area began on July 16, 1769, when a Spanish exploration party, commanded by Gaspar de Portola (with Father Junipero Serra in charge of religious conversion of the native populations), arrived by the overland route to secure California for the Spanish (Palou 1926). The natural attraction of the harbor at San Diego and the

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Cultural Resources Survey Report for the West Bobier Drive Project establishment of a military presence in the area solidified its importance to the Spanish colonization of the region and the growth of the civilian population.

Missions were constructed from San Diego to as far north as San Francisco. The mission locations were based upon a number of important territorial, military, and religious considerations.

Grants of land were made to those who applied, but many tracts reverted back to the government due to lack of use. As an extension of territorial control by the Spanish, each mission was placed so as to command as much territory and as large a population as possible. While primary access to California during the Spanish Period was by sea, the route of El Camino Real served as the land route for transportation, commercial, and military activities within the colony. This route was considered to be the most direct path between the missions (Rolle 1969; Caughey 1970). As increasing numbers of Spanish and Mexican peoples, as well as the later Americans during the Gold Rush, settled in the area, the Native American populations diminished as they were displaced or decimated by disease (Carrico and Taylor 1983).

Mexican Period (1821 to 1846)
Father Miguel Hidalgo y Costilla and a group of Native American followers began a revolt against Spanish rule on September 16, 1810. Hidalgo did not succeed in the fight against the Spanish and was ultimately executed. However, the revolt continued, and the Spanish were finally defeated in 1821. Mexican Independence Day is celebrated on September 16 of each year in honor of Father Hidalgo's bravery. The revolution also had repercussions in the northern territories and, by 1834, all of the mission lands in Alta California had been removed from the control of the Franciscan Order under the Acts of Secularization. Without proper maintenance, the missions quickly began to disintegrate. After 1836, missionaries ceased to make regular visits to the outlying Native American communities to minister to their needs (Engelhardt 1920). Large tracts of land continued to be granted to those who applied or who had gained favor with the Mexican government, land grants were also used to settle government debts, and the Mexican government was called upon to reaffirm some older Spanish land grants shortly before the Mexican -American War in 1846 (Moyer 1969).

Anglo-American Period (1846 to Present)
California was invaded by United States troops during the Mexican -American War from 1846 to 1848. The acquisition of strategic Pacific ports and California land was one of the principal objectives of the war (Price 1967). At the time, the inhabitants of California were practically defenseless, and they quickly surrendered to the United States Navy in July 1847 (Bancroft 1886).

The cattle ranchers of the "counties" of southern California prospered during the cattle boom of the early 1850s. They were able to "reap windfall profit . .. pay taxes and lawyer's bills . . . and generally live according to custom" (Pitt 1966). However, cattle ranching soon declined, contributing to the expansion of agriculture. With the passage of the "No Fence Act," San Diego's economy shifted from stock raising to farming (Robinson 1948). The act allowed for the expansion of unfenced farms, which was crucial in an area where fencing material was practically

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Cultural Resources Survey Report for the West Bobier Drive Project unavailable. Five years after its passage, most of the arable lands in San Diego County had been patented as either ranchos or homesteads, and growing grain crops replaced raising cattle in many of the county's inland valleys (Blick 1976; Elliott 1883 [1965]).

By 1870, farmers had learned to dry farm and were coping with some of the peculiarities of San Diego County's climate (San Diego Union 1868; Van Dyke 1886). Between 1869 and 1871, the amount of cultivated acreage in the county rose from less than 5,000, to more than 20,000, acres (San Diego Union 1872). Of course, droughts continued to hinder the development of agriculture (Crouch 1915; San Diego Union 1870; Shipek 1977). Large-scale farming in San Diego County was limited by a lack of water and the small size of arable valleys. The small urban population and poor roads also restricted commercial crop growing. Meanwhile, cattle continued to be grazed in parts of inland San Diego County. In the Otay Mesa area, for example, the "No Fence Act" had little effect upon cattle farmers because ranches were spaced far apart and natural ridges kept the cattle out of nearby growing crops (Gordinier 1966).

During the first two decades of the twentieth century, the population of San Diego County continued to grow. The population of the inland portion of the county declined during the 1890s, but, between 1900 and 1910, it rose by about 70 percent. The pioneering efforts were over, the railroads had broken the relative isolation of southern California, and life in San Diego County became similar to other communities throughout the west. After World War I, the history of San Diego County was primarily determined by the growth of San Diego Bay. In 1919, the United States Navy decided to make the bay the home base for the Pacific Fleet (Pourade 1967) and, in the 1920s, the bay became the home to the aircraft industry (Heiges 1976). The establishment of these industries led to the growth of the county as a whole; however, most of the civilian population growth occurred in the coastal areas in the northern portion of the county where the population almost tripled between 1920 and 1930. During this time period, the history of inland San Diego County was subsidiary to that of the city of San Diego, which had become a Navy center and an industrial city (Heiges 1976). In inland San Diego County, agriculture became specialized, and recreational areas were established in the mountain and desert areas. Just before World War II, urbanisation began to spread to the inland parts of the county.

3.2.4 General History of the City of Vista
Three rancho land grants, Rancho Buena Vista, Rancho Guajome, and Rancho Agua Hedionda, were located in what is now the city of Vista. Rancho Buena Vista was granted to Felipe Subria, a Luisefio Native American and Christian convert, by Governor Pio Pico in 1845.

Rancho Buena Vista encompassed almost 119 acres in what is now the center of the city of Vista (Marben-Laird Associates 1987; Rancho Buena Vista 2017). Subria built a home along Buena Vista Creek; however, no remnants of this structure are currently present. The property was deeded to Subria's daughter, Maria La Garcia Dunn, for $1.00. Dunn and her husband, William, an American soldier, deeded the property to Jesus Machado for $3,000 in April of 1852, who then began construction on the Buena Vista Adobe. Although subsequent owners made additions and

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Cave Couts purchased Rancho Buena Vista in 1866. Couts's acquisition of the property brought Rancho Guajome and Rancho Buena Vista under the ownership of the same family. When Couts married Ysidora Bandini, the Bandini family gifted Rancho Guajome to the couple as a wedding present. Ownership of Rancho Buena Vista later transferred to Cave and Ysidora Couts's daughter, Maria Antonia, and her husband, Chalmers Scott, in the 1870s. Scott and Cave Couts Jr., the son of Cave Couts, were eager to increase the town's status and convinced Maria to give land to the Atchison, Topeka and Santa Fe Railway for the construction of tracks and a new station.

Railroad tracks connecting Oceanside and Escondido were completed in 1887, which helped facilitate the development of Vista (Marben-Laird Associates 1987; Rancho Buena Vista 2017).

Throughout the late nineteenth century, a series of land disputes and sales decreased the size of Rancho Buena Vista as smaller agricultural holdings were established. Inability to secure dependable access to water caused many small farms to fail. Nevertheless, in 1879, the region was eventually able to support a successful agricultural community with the Buena Vista Winery, and later, avocado and citrus crops. John Frazer founded the town post office in 1882, officially giving the town the name of Vista. Frazer had attempted to name the town either "Frazer's Crossing" or "Buena Vista"; however, those names had already been taken, so he eventually settled on "Vista" (Marben-Laird Associates 1987; City of Vista 2017).

The Vista Irrigation District was founded in 1923 and provided the funding necessary to develop access to water from Lake Henshaw. This new dependable water source and access to the railroad allowed the agricultural industry in the Vista area to flourish throughout the twentieth century. The city incorporated on January 28, 1963. Throughout the twentieth century, residential development increased population through the subdivision of old farm lots for tract homes and the construction of apaitinent complexes. Industry in the region also shifted from agriculture to manufacturing as new business parks were constructed. Between 1963 and 2004, the population of the city grew from about 19,000 to 94,000, and is expected to continue to grow (City of Vista 2017).

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4.0 METHODOLOGY
The Phase I cultural resource survey of the West Bobier Drive Project consisted of institutional records searches, a pedestrian archaeological survey of the project, and preparation of this report. This study was conducted in conformance with City of Vista guidelines and CEQA Section 15064.5 criteria. Specific definitions for archaeological resource type(s) used in this report are those established by the State Historic Preservation Office (SHPO 1995). The report format follows the Archaeological Resource Management Report guidelines. The results of the assessment are discussed in detail in Section 5.0.

4.1 Archaeological Records Search
BFSA requested a records search from the SCIC at SDSU for an area of one-half mile surrounding the project in order to determine the presence of any previously recorded archaeological sites. The complete results of the records search are provided in Appendix C and discussed in Section 5.1. The SCIC search also included a standard review of the National Register of Historic Places (NRHP) and the Office of Historic Preservation (OHP) Built Environment Resources Directory (BERD). Land patent records, held by the Bureau of Land Management (BLM) and accessible through the BLM General Land Office (GLO) website, were also reviewed for pertinent project information. In addition, the BFSA research library was consulted for any relevant historical information.

4.2 Field Methodology
BFSA Director of Field Operations Clarence L. Hoff conducted the survey of the West Bobier Drive Project on August 27, 2024, under the direction of Principal Investigator Tracy A.

Stropes, M.A., RPA. Parallel survey transects spaced at 10 -meter intervals were utilized throughout the entire project and photographs were taken to document project conditions (see Section 5.2).

4.3 Report Preparation and Recordation
This report contains information regarding previous studies, statutory requirements for the project, a brief description of the setting, research methods employed, and the overall results of the survey. The report includes all appropriate illustrations and tabular information needed to make a complete and comprehensive presentation of these activities, including the methodologies employed and the personnel involved. A copy of this report will be placed at the SCIC at SDSU.

Any newly recorded sites or sites requiring updated information will be recorded on the appropriate Department of Parks and Recreation (DPR) site forms, which will be filed at the SCIC.

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4.4 Native American Consultation
BFSA also requested a SLF search from the NAHC. The SLF search results were positive for Native American sacred sites or locations of religious or ceremonial importance within the vicinity of the project. All correspondence is provided in Appendix D.

4.5 Applicable Regulations
Resource importance is assigned to districts, sites, buildings, structures, and objects that possess exceptional value or quality illustrating or interpreting the heritage of Vista in history, architecture, archaeology, engineering, and culture. Specifically, criteria outlined in CEQA provide the guidance for making such a determination. The following sections detail the criteria that a resource must meet in order to be determined important.

4.5.1 California Environmental Quality Act
According to CEQA, (§ 15064.5a), the term "historical resource" includes the following:
1) A resource listed in, or determined to be eligible by, the State Historical Resources Commission, for listing in the CRHR (Public Resources Code [PRC] SS5024.1, Title 14 CCR [California Code of Regulations]. Section 4850 et seq.). 2) A resource included in a local register of historical resources, as defined in Section 5020.1(k) of the PRC or identified as significant in a historical resource survey meeting the requirements of Section 5024.1(g) of the PRC, shall be presumed to be historically or culturally significant. Public agencies must treat any such resource as significant unless the preponderance of evidence demonstrates that it is not historically or culturally significant.
3) Any object, building, structure, site, area, place, record, or manuscript, which a lead agency determines to be historically significant or significant in the architectural, engineering, scientific, economic, agricultural, educational, social, political, military, or cultural annals of California may be considered a historical resource, provided the lead agency's determination is supported by substantial evidence in light of the whole record. Generally, a resource shall be considered by the lead agency to be "historically significant" if the resource meets the criteria for listing on the CRHR (PRC SS5024.1, Title 14, Section 4852), including the following:
a) Is associated with events that have made a significant contribution to the broad patterns of California's history and cultural heritage; b) Is associated with the lives of persons important in our past; c) Embodies the distinctive characteristics of a type, period, region, or method of construction, or represents the work of an important creative individual, or possesses high artistic values; or

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Cultural Resources Survey Report for the West Bobier Drive Project d) Has yielded, or may be likely to yield, information important in prehistory or history.
4) The fact that a resource is not listed in, or determined eligible for listing in, the CRHR, not included in a local register of historical resources (pursuant to Section 5020.1[k] of the PRC), or identified in a historical resources survey (meeting the criteria in Section 5024.1[g] of the PRC) does not preclude a lead agency from determining that the resource may be a historical resource as defined in PRC Section 5020.1(j) or 5024.1.

According to CEQA, Section 15064.5(b), a project with an effect that may cause a substantial adverse change in the significance of a historical resource is a project that may have a significant effect upon the environment. CEQA defines a substantial adverse change as:
1) Substantial adverse change in the significance of a historical resource means physical demolition, destruction, relocation, or alteration of the resource or its immediate surroundings such that the significance of a historical resource would be materially impaired.
2) The significance of a historical resource is materially impaired when a project:
a) Demolishes or materially alters in an adverse manner those physical characteristics of a historical resource that convey its historical significance and that justify its inclusion in, or eligibility for, inclusion in the CRHR; or b) Demolishes or materially alters in an adverse manner those physical characteristics that account for its inclusion in a local register of historical resources pursuant to Section 5020.1(k) of the PRC or its identification in a historical resources survey meeting the requirements of Section 5024.1(g) of the PRC, unless the public agency reviewing the effects of the project establishes by a preponderance of evidence that the resource is not historically or culturally significant; or,
c) Demolishes or materially alters in an adverse manner those physical characteristics of a historical resource that convey its historical significance and that justify its eligibility for inclusion in the CRHR as determined by a lead agency for purposes of CEQA.

Section 15064.5(c) of CEQA applies to effects upon archaeological sites and contains the following additional provisions regarding archaeological sites:

1. When a project will impact an archaeological site, a lead agency shall first determine whether the site is a historical resource, as defined in subsection (a).

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2. If a lead agency determines that the archaeological site is a historical resource, it shall refer to the provisions of Section 21084.1 of the PRC, Section 15126.4 of the guidelines, and the limits contained in Section 21083.2 of the PRC do not apply.

3. If an archaeological site does not meet the criteria defined in subsection (a) but does meet the definition of a unique archaeological resource in Section 21083.2 of the PRC, the site shall be treated in accordance with the provisions of Section 21083.2. The time and cost limitations described in PRC Section 21083.2(c -f) do not apply to surveys and site evaluation activities intended to determine whether the project location contains unique archaeological resources.

4. If an archaeological resource is neither a unique archaeological nor historical resource, the effects of the project upon those resources shall not be considered a significant effect upon the environment. It shall be sufficient that both the resource and the effect upon it are noted in the Initial Study or Environmental Impact Report, if one is prepared to address impacts upon other resources, but they need not be considered further in the CEQA process.

Sections 15064.5(d) and (e) contain additional provisions regarding human remains.

Regarding Native American human remains, paragraph (d) provides:
(d) When an Initial Study identifies the existence of, or the probable likelihood of, Native American human remains within the project, the lead agency shall work with the appropriate Native Americans as identified by the NAHC, as provided in PRC SS5097.98. The applicant may develop an agreement for treating or disposing of, with appropriate dignity, the human remains and any items associated with Native American burials with the appropriate Native Americans as identified by the NAHC. Action implementing such an agreement is exempt from:
1) The general prohibition on disinterring, disturbing, or removing human remains from any location other than a dedicated cemetery (Health and Safety Code Section 7050.5).
2) The requirements of CEQA and the Coastal Act.

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5.0 RESULTS

5.1 Records Search Results
An archaeological records search for the project and the surrounding area within a one- half -mile radius was conducted by BFSA at the SCIC at SDSU (Appendix C). The search results identified six cultural resources within one-half mile of the project. One of which, prehistoric bedrock milling site SDI -5345 is mapped within the subject property. Site SDI -5345 was originally recorded in 1975 by B. Underwood as a prehistoric bedrock milling site and associated artifact scatter. The site was mapped within the current alignment of West Bobier Drive extending to the north and south of the current road alignment. The site has been studied multiple times, evaluated as not eligible for the CRHR, and most of the recorded milling features have been destroyed (Chace 1978; Giletti and Robbins -Wade 2008; Robbins -Wade and Giletti 2013). The remaining five resources are also prehistoric, consisting of one lithic scatter and four additional bedrock milling sites with varying degrees of associated features and artifacts.

Table 5.1-1
Previously Recorded Cultural Resources
Within a One -Half -Mile Radius of the Project
Site Number(s)
Site Description
SDI -4992
Prehistoric lithic scatter
SDI -5345*
Prehistoric bedrock milling site with
associated artifact scatter
SDI -6088
(has subsumed SDI -6089 and SDI -6090)
Prehistoric bedrock milling site with
associated artifact scatter
SDI -6092
Prehistoric bedrock milling site
SDI -6093
Prehistoric bedrock milling site with
associated lithic scatter
SDI -8241
Prehistoric bedrock milling site with
associated pictographs, midden, and artifact
scatter
* Recorded within the subject property.

The results of the SCIC records search also indicate that four archaeological investigations overlap the subject property (Chace 1978; Marben-Laird Associates 1987; Rosenberg et al. 2007; Giletti and Robbins -Wade 2008) (Table 5.1-2).

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Cultural Resources Survey Report for the West Bobier Drive Project Table 5.1-2
Archaeological Studies Mapped by the SCIC Overlapping the Project Chace, Paul
1978 An Archaeological Test Excavation at SDi-5345, the Church Site, City of Vista. Paul G. Chace and Associates. Unpublished report on file at the South Coastal Information Center at San Diego State University, San Diego, California.

Giletti, Andrew and Mary Robbins -Wade
2008 Archaeological Resources Survey, Bobier Property (APN 161-030-07), Vista, San Diego, California. Affinis. Unpublished report on file at the South Coastal Information Center at San Diego State University, San Diego, California.

Marben-Laird Associates
1987 Historic Resource Survey: A Project of the City of Vista, California. Marben-Laird Associates.

Unpublished report on file at the South Coastal Information Center at San Diego State University, San Diego, California.

Rosenberg, Seth A., Adriane Dorrler, and Brian F. Smith 2007 A Cultural Resources Evaluation for the Vista and Buena Sanitation District 2007 Sewer Master Plan Update. Brian F. Smith and Associates. Unpublished report on file at the South Coastal Information Center at San Diego State University, San Diego, California.

Of the four reports overlapping the proposed project only Chace (1978) and Giletti and Robbins -Wade (2008) directly address the subject property. Chace tested and evaluated site SDI - 5345 in 1978. Chace found Site SDI -5345 to be not eligible for the CRHR and, therefore, not CEQA-significant. As a result, the site was partially destroyed for the extension of West Bobier Drive between 1981 and 1983. In 2008, Giletti and Robbins -Wade studied the current project in anticipation of a residential development. Giletti and Robbins -Wade (2008) identified two bedrock milling features, each with a single milling slick, and two fragments of marine shell and one piece of debitage associated with Site SDI -5345 within the subject property. No photos or sketches of the features were included in the 2008 study; however, Giletti and Robbins -Wade did extend the site boundary further south into the subject property as a result of their findings. Regardless, Giletti and Robbins -Wade (2008) concluded that what remains of Site SDI -5345 within the subject property is not CRHR-eligible. One additional, adjacent, study is relevant to the subject property.

In 2013, in support of the residential development of the property across West Bobier Drive from the current project, Robbins -Wade and Giletti conducted additional archaeological testing of remnant elements of Site SDI -5345. The 2013 results concurred with the previous evaluations of the resource as not eligible for the CRHR (Robbins -Wade and Giletti 2013).

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Cultural Resources Survey Report for the West Bobier Drive Project Additionally, the following sources were also consulted by BFSA:
• The NRHP index
• The OHP Archaeological Determinations of Eligibility
• The OHP BERD
• Historic aerial photographs from 1938 through 2023
• BLM GLO records
• 1893, 1901, and 1942 Oceanside, California (15 -minute) USGS topographic maps • 1948 and 1968 San Luis Rey, California (7.5 -minute) USGS topographic maps Based on these additional sources, the subject property was vacant until sometime between 1901 and 1938. The 1938 aerial photograph depicts one structure, possibly an ancillary structure, within the subject property that appears to be associated with the agricultural use of the surrounding area.

By 1946, an additional structure, likely a residence, is also visible within the property. Subsequent photographs show the regular use and clearing of the property along with the development of the surrounding parcels. Between 2008 and 2009, all structures within the property were removed.

BFSA also requested a SLF search from the NAHC. The SLF search results were positive for Native American sacred sites or locations of religious or ceremonial importance within the vicinity of the project. All correspondence is provided in Appendix D.

5.2 Field Investigation
The archaeological survey was completed on August 27, 2024, by BFSA Director of Field Operations Clarence L. Hoff. Aerial photographs, maps, and a mobile Trimble Global Positioning System unit permitted orientation and location of the project boundaries. The entire property was surveyed by employing 10 -meter spaced transects. The surface of the subject property, including all exposed ground surfaces, rodent burrows, and disturbed areas, was carefully inspected. A survey form, field notes, and photographs documented the survey work undertaken.

During the survey, signs of the past development and clearing of the property were noted.

Ground visibility was, at times, limited by vegetation and the previous disturbances. Vegetation observed within the property consisted primarily of non-native weeds and grasses along with some remnant pepper and palm trees. Although both structures identified within the property during the aerial photograph review have been removed, impacts from previous clearing and rough grading were noted throughout the parcel. In addition, piles of pushed dirt, concrete, and rocks were noted throughout the property and the remnants of a block retaining wall and concrete driveway were observed in the northeast corner of the parcel (Plates 5.2-1 through 5.2-4).

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Cultural Resources Survey Report for the West Bobier Drive Project Plate 5.2-1: Overview of the subject property, facing north.

Plate 5.2-2: Overview of the subject property, facing south.

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Cultural Resources Survey Report for the West Bobier Drive Project Plate 5.2-3: Overview of the subject property, facing northwest.

Plate 5.2-4: Overview of the remnant driveway, facing northeast.

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Cultural Resources Survey Report for the West Bobier Drive Project No new cultural resources or any artifacts associated with previously recorded site SDI - 5345 were identified during the survey. However, the survey did identify two milling features (BMF 1 and BMF 2) which match the description of those identified by Giletti and Robbins -Wade in 2008. Feature BMF 1 measures approximately 50 by 60 centimeters and consists of a low-lying outcrop with a single milling slick. A survey marker has been set into the center of the feature (Plates 5.2-5 and 5.2-6). Feature BMF 2 is also a low-lying outcrop containing a single slick.

Feature BMF 2 measures approximately 40 by 35 centimeters (Plates 5.2-7 and 5.2-8). The locations of Features BMF 1 and BMF 2 are presented on Figures 5.2-1 and 5.2-2 and depicted on the DPR update form found within Appendix B. Again, the features are already located within the SDI -5345 site boundary and no new information was identified which would alter the previous evaluation of the site as not CRHR-eligible. Rather, the impacts to the site through past study, removal of features, development, and clearing have further diminished the site's integrity.

Plate 5.2-5: Overview of BMF 1, facing northwest.

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Cultural Resources Szuvey Report for the West Bobier Drive Project Plate 5.2-6: Closeup of BMF 1, facing west.

Plate 5.2-7: Overview of BMF 2, facing northeast.

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Cultural Resources Survey Report for the West Bobier Drive Project Plate 5.2-8: Closeup of BMF 2, facing northeast.

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Cultural Resources Survey Report for the West Bobier Drive Project Figure 5.2-1
Cultural Resource Location Map
(Deleted for Public Review; Bound Separately)

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Cultural Resources Survey Report for the West Bobier Drive Project Figure 5.2-2
Site SDI -5345 Feature Location Map
(Deleted for Public Review; Bound Separately)

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6.0 MANAGEMENT CONSIDERATIONS/RECOMMENDATIONS
The Phase I cultural resources assessment for the West Bobier Drive Project identified two previously recorded bedrock milling features (BMF 1 and BMF 2) associated with Site SDI -5345 within the subject property. Based upon the current project design, Features BMF 1 and BMF 2 will be impacted by the proposed project (Figure 6.0-1). However, no associated artifacts were observed, and previous testing and evaluation have already determined that the site is not eligible for the CRHR. Therefore, the resource is not considered a Historical Resource under CEQA criteria and impacts associated with the proposed project are not considered significant.

Although Site SDI -5345 is not eligible for the CRHR, the property has been disturbed due to previous development and clearing. Further, ground visibility was, at times, hindered during the survey. As evident from the records search results, the surrounding area remains sensitive for prehistoric resources. Given the records search results, the limited visibility within portions of the project area during the survey, and the documented presence of Site SDI -5345 within the property, there remains the potential for the inadvertent discovery of archaeological resources during grading. Therefore, it is recommended that the project be conditioned with archaeological and Native American monitoring during grading of the subject property.

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Cultural Resources Survey Report for the West Bobier Drive Project Figure 6.0-1
Site SDI -5345 on Project Development Map
(Deleted for Public Review; Bound Separately)

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7.0 PERSONNEL
Principal Investigator Tracy A. Stropes, M.A., RPA, directed the archaeological study of the West Bobier Drive Project. Director of Field Operations Clarence L. Hoff conducted the field survey. Andrew J. Garrison, M.A., RPA, prepared the text. Emily T. Soong created the graphics and Shawna M. Krystek conducted the technical editing and report production.

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8.0 CERTIFICATION
I hereby certify that the statements furnished above and in the attached exhibits present the data and information required for this archaeological report, and that the facts, statements, and information presented are true and correct to the best of my knowledge and belief and have been compiled in accordance with CEQA criteria as defined in Section 15064.5 and City of Vista cultural resource criteria.

September 13, 2024
Andrew J. Garrison, MA., RPA Date
Project Archaeologist
08/11/2026

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9.0 REFERENCES CITED
Bada, Jeffrey L., Roy A. Schroeder, and George F. Carter 1974 New Evidence for the Antiquity of Man in America Deduced from Aspartic Acid Racemization. Science 184:791-793.

Bancroft, Hubert Howe
1886 History of California (Volume V; 1846-1848). The History Company, San Francisco, California.

Beauchamp, R. Mitchel
1986 A Flora of San Diego County, California. Sweetwater River Press, National City, California.

Blick, J.D.
1976 Agriculture in San Diego County. In San Diego — An Introduction to the Area. Edited by Philip Pryde. Kendall/Hunt Publishing Company, Dubuque, Iowa.

Bull, C.
1983 Shaking the Foundations: The Evidence for San Diego Prehistory. In Cultural Resource Management Casual Papers 1(3):15-64. Department of Anthropology, San Diego State University.
1987 A New Proposal: Some Suggestions for San Diego Prehistory. In San Dieguito-La Jolla: Chronology and Controversy, edited by Dennis Gallegos, pp. 35-42. San Diego County Archaeological Society Research Paper No. 1.

Cardenas, D. Sean
1986 Avocado Highlands: An Inland Late La Jolla and Preceramic Yuman Site from Southern San Diego County. In Cultural Resource Management Casual Paper 2(2).

Depaitiiient of Anthropology, San Diego State University.

Carrico, Richard L. and Clifford V.F. Taylor
1983 Excavation of a Portion of Ystagua: A Coastal Valley Ipai Settlement. Unpublished report on file at the City of San Diego Planning Department, Environmental Quality Division, San Diego, California.

Carter, George F.
1957 Pleistocene Man at San Diego. Johns Hopkins Press, Baltimore. 1980 Earlier than You Think: A Personal View of Man in America. Texas A&M University Press, College Station.

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Cultural Resources Survey Report for the West Bobier Drive Project Caughey, John W.
1970 California: A Remarkable State's Life History (Third Edition). Prentice -Hall, Englewood Cliffs, New Jersey.

Chace, Paul
1978 An Archaeological Test Excavation at Site SDi-5345, the Church Site, City of Vista.

Paul G. Chace and Associates. Unpublished report on file at the South Coastal Information Center, San Diego State University, San Diego, California.

Chapman, Charles E.
1921 A History of California: The Spanish Period. The Macmillan Company, New York.

City of Vista
2017 History of Vista. Electronic document, http://www.cityofvista.com/about- vista/history, accessed September 15, 2017.

Crouch, Herbert
1915 Reminiscences, 1868-1915. Unpublished manuscript, California Room, San Diego Public Library; and SDHS Library, Serra Museum.

Davis, E.L., C.W. Brott, and D.L. Weide
1969 The Western Lithic Co -Tradition. San Diego Museum Papers (6). San Diego Museum of Man, San Diego.

Demere, Thomas A. and Stephen L. Walsh
1993 Paleontological Resources, County of San Diego. Depaitiirent of Paleontology, San Diego Natural History Museum.

Elliott, Wallace W.
1883 History of San Bernardino and San Diego Counties (1965 Edition). Riverside Museum Press, Riverside, California.

Engelhardt, Zephryn
1920 San Diego Mission. James M. Barry Company, San Francisco.

Ezell, Paul H.
1983 A New Look at the San Dieguito Culture. Cultural Resource Management Casual Papers 1(3):103-109. Department of Anthropology, San Diego State University, San Diego.
1987 The Harris Site — An Atypical San Dieguito Site, or am I Beating a Dead Horse? In San Dieguito-La Jolla: Chronology and Controversy, edited by Dennis Gallegos, pp. 15-

22. San Diego County Archaeological Society Research Paper No. 1.

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Cultural Resources Survey Report for the West Bobier Drive Project Gallegos, Dennis R.
1987 A Review and Synthesis of Environmental and Cultural Material for the Batiquitos Lagoon Region. In San Dieguito-La Jolla: Chronology and Controversy, edited by D.

Gallegos. San Diego County Archaeological Society Research Paper 1:23-34.

Gallegos, Dennis R. and Carolyn E. Kyle
1988 Five Thousand Years of Maritime Subsistence at Ballast Point Prehistoric Site SDI -48 (W-164) San Diego, California. Unpublished report on file at the South Coastal Information Center at San Diego State University, San Diego, California.

Giletti, Andrew and Mary Robbins -Wade
2008 Archaeological Resources Survey, Bobier Property (APN 161-030-07), Vista, San Diego County, California. Affinis. Unpublished report on file at the South Coastal Information Center at San Diego State University, San Diego, California.

Gordinier, Jerry G.
1966 Problems of Settlement in the San Diego Foothills. Thesis, San Diego State College, San Diego.

Heiges, Harvey
1976 The Economic Base of San Diego County. In San Diego An Introduction to the Region. Edited by Philip Pryde. Kendall/Hunt Publishing Company, Dubuque, Iowa.

King, Chester DeWitt
1982 The Evolution of Chumash Society: A Comparative Study of Artifacts Used for Social System Maintenance in the Santa Barbara Channel Region Before AD 1804. Ph.D. dissertation, Depaitinent of Anthropology, University of California, Davis.

Kyle, Carolyn, Adella Schroth, and Dennis R. Gallegos
1990 Early Period Occupation at the Kuebler Ranch Site SDI -8,654 Otay Mesa, San Diego County, California. Prepared for and on file at the County of San Diego, Department of Public Works by ERCE Environmental and Energy Services Co., San Diego, California.

Marben-Laird Associates
1987 Historic Resource Survey: A Project of the City of Vista, California. Marben-Laird Associates. Unpublished report on file at the South Coastal Information Center at San Diego State University, San Diego, California.

Minshall, Herbert L.
1976 The Broken Stones. Copley Books, San Diego.
1989 Buchanan Canyon: Ancient Human Presence in the Americas. Slawson Communications, San Marcos, California.

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Cultural Resources Survey Report for the West Bobier Drive Project Moratto, Michael J.
1984 California Archaeology. Academic Press, New York.

Moriarty, James R., III
1966 Culture Phase Divisions Suggested by Topological Change Coordinated with Stratigraphically Controlled Radiocarbon Dating in San Diego. Anthropological Journal of Canada 4(4):20-30.
1967 Transitional Pre -Desert Phase in San Diego, California. Science 155(3762):553-336.

Scripps Institution — UCSD Contribution No. 2278.
1969 San Dieguito Complex: Suggested Environmental and Cultural Relationships.

Anthropological Journal of Canada 7(3):2-18.

Moriarty, James R., III and Herbert L. Minshall
1972 A New Pre -Desert Site Discovered near Texas Street. Anthropological Journal of Canada 10(3):10-13.

Moyer, Cecil C.
1969 Historic Ranchos of San Diego. Edited by Richard F. Pourade. Union -Tribune Publishing Company, San Diego.

Natural Resources Conservation Service (NRCS)
2024 Web Soil Survey Soil Map. Electronic document,
https://websoilsurvey.sc.egov.usda.gov/App/WebSoilSurvey.aspx , accessed July 2024.

Norris, R.M. and R.W. Webb
1990 Geology of California (second edition). John Wiley and Sons, Inc., New York, New York.

Palou, Fray Francisco
1926 Historical Memoirs of New California. Edited by Herbert Eugene Bolton (4 Volumes).

University of California Press, Berkeley.

Pitt, Leonard
1966 The Decline of the Californios. University of California Press, Los Angeles.

Pourade, Richard F.
1967 The Rising Tide: Southern California in the Twenties and Thirties. Union -Tribune Publishing Company, San Diego.

Price, Glenn W.
1967 Origins of the War with Mexico. University of Texas Press, Austin.

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Cultural Resources Survey Report for the West Bobier Drive Project Rancho Buena Vista
2017 The History of the Rancho Buena Vista Adobe. Electronic document, http://ranchobuenavistaadobe.com/history , accessed September 15, 2017.

Raven -Jennings, Shelly and Brian F. Smith
1999a Final Report for Site SDI -8330/W-240 "Scraper Hill," Escondido, California.

Unpublished report on file at the South Coastal Information Center at San Diego State University, San Diego, California.
1999b Report of Excavations at CA -SDI -4608: Subsistence and Technology Transitions during the Mid -to -Late Holocene in San Diego County (Scripps Poway Parkway).

Unpublished report on file at the South Coastal Information Center at San Diego State University, San Diego, California.

Reeves, Brian O.K.
1985 Early Man in the Americas: Who, When, and Why. In Woman, Poet, Scientist: Essays in New World Anthropology Honoring Dr. Emma Louise Davis, edited by Thomas C.

Blackburn, pp. 79-104. Ballena Press Anthropological Papers No. 29. Los Altos, California.

Reeves, Brian, John M.D. Pohl, and Jason W. Smith.
1986 The Mission Ridge Site and the Texas Street Question. In New Evidence for the Pleistocene Peopling of the Americas, edited by Alan Lyle Bryan, pp. 65-80. Center for the Study of Early Man, University of Maine, Orono.

Robbins -Wade, Mary Judith
1990 Prehistoric Settlement Pattern of Otay Mesa San Diego County, California. Thesis, Department of Anthropology, San Diego State University.

Robbins -Wade, Mary and Andrew Giletti
2013 Cultural Resources Survey and Assessment, Vista Ridge Apartments, Vista, San Diego County, California. Affinis. Unpublished report on file with the South Coastal Information Center at San Diego State University, San Diego, California.

Robinson, W.W.
1948 Land in California. University of California Press, Berkeley.

Rogers, Malcolm
1966 Ancient Hunters of the Far West. Edited with contributions by H.M. Worthington, E.L.

Davis, and Clark W. Brott. Union Tribune Publishing Company, San Diego.

Rolle, Andrew F.
1969 California: A History (Second Edition). Thomas Y. Crowell Company, New York.

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Cultural Resources Survey Report for the West Bobier Drive Project Rosenberg, Seth A., Adrian Dorrler, and Brian F. Smith
2007 A Cultural Resources Evaluation for the Vista and Buena Sanitation District 2007 Sewer Master Plan Update. Brian F. Smith and Associates. Unpublished report on file at the South Coastal Information Center at San Diego State University, San Diego, California.

San Diego Union
1868 San Diego history. 6 February. San Diego, California. 1870 San Diego history. 23 June. San Diego, California. 1872 San Diego history. 2 January. San Diego, California.

Shipek, Florence
1977 A Strategy for Change: The Luiseno of Southern California. Dissertation on file at the University of Hawaii.

Shumway, George, Carl L. Hubbs, and James R. Moriarty, III 1961 Scripps Estate Site, San Diego, California: A La Jollan Site Dated 5,460-7,370 Years Before the Present. Annals of the New York Academy of Sciences 93(3).

Smith, Brian F.
1996 The Results of a Cultural Resource Study at the 4S Ranch. Unpublished report on file at the South Coastal Information Center at San Diego State University, San Diego, California.

Smith, Brian F. and James R. Moriarty, III
1985a The Archaeological Excavations at Site W-20, Sierra Del Mar. Unpublished report on file at the South Coastal Information Center at San Diego State University, San Diego, California.
1985b The Archaeological Excavations at Batiquitos Pointe and Batiquitos Bluffs.

Unpublished report on file at the City of Carlsbad, Carlsbad, California.

State Historic Preservation Office (SHPO)
1995 Instructions for Recording Historical Resources. Office of Historic Preservation, Sacramento.

Stropes, Tracy A.
2007 Nodule Industries of North Coastal San Diego: Understanding Change and Stasis in 10,000 Years of Lithic Technology. Submitted to San Diego State University. Thesis on file at San Diego State University, San Diego, California.

True, Delbert L.
1958 An Early Complex in San Diego County, California. American Antiquity 23(3).

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Cultural Resources Survey Report for the West Bobier Drive Project 1966 Archaeological Differentiation of the Shoshonean and Yuman Speaking Groups in Southern California. Dissertation, University of California Los Angeles. 1970 Investigations of a Late Prehistoric Complex in Cuyamaca Rancho State Park, San Diego County, California. Archaeological Survey Monograph. University of California, Los Angeles.
1980 The Pauma Complex in Northern San Diego County: 1978. Journal of New World Archaeology 3(4):1-39.
1986 Molpa, a Late Prehistoric Site in Northern San Diego County: The San Luis Rey Complex, 1983. In Symposium: A New Look at Some Old Sites, edited by Gary S.

Breschini and Trudy Haversat, pp. 29-36. Coyote Press, Salinas.

True, D.L. and Eleanor Beemer
1982 Two Milling Stone Inventories from Northern San Diego County, California. Journal of California and Great Basin Anthropology 4:233-261.

True, D.L. and R. Pankey
1985 Radiocarbon Dates for the Pauma Complex Component at the Pankey Site, Northern San Diego County, California. Journal of California and Great Basin Anthropology 7:240-244.

Van Dyke, Theodore
1886 Southern California. Fords, Howard and Hulbert.

Warren, Claude N.
1964 Cultural Change and Continuity on the San Diego Coast. Dissertation on file at the University of California, Los Angeles.
1966 The San Dieguito Type Site: Malcolm J. Roger's 1938 Excavation on the San Dieguito River. San Diego Museum Papers (6).

Warren, Claude L., Gretchen Siegler, and Frank Dittmer
1998 Paleoindian and Early Archaic Periods, In Prehistoric and Historic Archaeology of Metropolitan San Diego: A Historical Properties Background Study (draft). Prepared for and on file at ASM Affiliates, Inc., San Diego, California.

Waugh, Georgie
1986 Intensification and Land -use: Archaeological Indication of Transition and Transformation in a Late Prehistoric Complex in Southern California. Dissertation, Department of Anthropology, University of California, Davis.

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APPENDIX A
Qualifications of Key Personnel
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Anclrew J. Garrison, M.A. K A
Project Archaeologist
I5F5A Environmental5ervices, a Perennial Company
19-010 Poway Road • 5uite A •
Prone: (858) 679-8218 • Fax: (858) 679-9896 • E -Mail: [email protected] Education
o 3))
BFSA Environmental Services
Master of Arts, Public History, University of California, Riverside Bachelor of Science, Anthropology, University of California, Riverside Bachelor of Arts, History, University of California, Riverside Professional Memberships
2009
2005
2005
Register of Professional Archaeologists
Society for California Archaeology
Society for American Archaeology
California Council for the Promotion of History
Experience
Society of Primitive Technology
Lithic Studies Society
California Preservation Foundation
Pacific Coast Archaeological Society
Project Archaeologist June 2017 -Present
BFSA Environmental Services, A Perennial Company Poway, California Project management of all phases of archaeological investigations for local, state, and federal agencies including National Register of Historic Places (NRHP) and California Environmental Quality Act (CEQA) level projects interacting with clients, sub -consultants, and lead agencies. Supervise and perform fieldwork including archaeological survey, monitoring, site testing, comprehensive site records checks, and historic building assessments. Perform and oversee technological analysis of prehistoric lithic assemblages. Author or co-author cultural resource management reports submitted to private clients and lead agencies.

Senior Archaeologist and GIS Specialist 2009-2017
Scientific Resource Surveys, Inc. Orange, California
Served as Project Archaeologist or Principal Investigator on multiple projects, including archaeological monitoring, cultural resource surveys, test excavations, and historic building assessments. Directed projects from start to finish, including budget and personnel hours proposals, field and laboratory direction, report writing, technical editing, Native American consultation, and final report submittal.

Oversaw all GIS projects including data collection, spatial analysis, and map creation.

Preservation Researcher 2009
City of Riverside Modernism Survey Riverside, California Completed DPR Primary, District, and Building, Structure and Object Forms for five sites for a grant - funded project to survey designated modern architectural resources within the City of Riverside. 08/11/2026
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If!:1 5A Environmental `services, A Perennial Company, 2 Information Officer 2005, 2008-2009
Eastern Information Center (EIC), University of California, Riverside Riverside, California Processed and catalogued restricted and unrestricted archaeological and historical site record forms.

Conducted research projects and records searches for government agencies and private cultural resource firms.

Keports/Papers
2019 A Class III Archaeological Study for the Tuscany Valley (TM 33725) Project National Historic Preservation Act Section 106 Compliance, Lake Elsinore, Riverside County, California.

Contributing author. Brian F. Smith and Associates, Inc. 2019 A Phase I and II Cultural Resources Assessment for the Jack Rabbit Trail Logistics Center Project, City of Beaumont, Riverside County, California. Brian F. Smith and Associates, Inc. 2019 A Phase I Cultural Resources Assessment for the 10575 Foothill Boulevard Project, Rancho Cucamonga, California. Brian F. Smith and Associates, Inc. 2019 Cultural Resources Study for the County Road and East End Avenue Project, City of Chino, San Bernardino County, California. Brian F. Smith and Associates, Inc. 2019 Phase II Cultural Resource Study for the McElwain Project, City of Murrieta, California.

Contributing author. Brian F. Smith and Associates, Inc. 2019 A Section 106 (NHPA) Historic Resources Study for the McElwain Project, City of Murrieta, Riverside County, California. Brian F. Smith and Associates, Inc. 2018 Cultural Resource Monitoring Report for the Sewer Group 818 Project, City of San Diego. Brian F.

Smith and Associates, Inc.
2018 Phase I Cultural Resource Survey for the Stone Residence Project, 1525 Buckingham Drive, La Jolla, California 92037. Brian F. Smith and Associates, Inc. 2018 A Phase I Cultural Resources Assessment for the Seaton Commerce Center Project, Riverside County, California. Brian F. Smith and Associates, Inc. 2017 A Phase I Cultural Resources Assessment for the Marbella Villa Project, City of Desert Hot Springs, Riverside County, California. Brian F. Smith and Associates, Inc. 2017 Phase I Cultural Resources Survey for TTM 37109, City of Jurupa Valley, County of Riverside. Brian F. Smith and Associates, Inc.
2017 A Phase I Cultural Resources Assessment for the Winchester Dollar General Store Project, Riverside County, California. Brian F. Smith and Associates, Inc. 2016 John Wayne Airport Jet Fuel Pipeline and Tank Farm Archaeological Monitoring Plan. Scientific Resource Surveys, Inc. On file at the County of Orange, California. 2016 Historic Resource Assessment for 220 South Batavia Street, Orange, CA 92868 Assessor's Parcel Number 041-064-4. Scientific Resource Surveys, Inc. Submitted to the City of Orange as part of Mills Act application.
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If!:1 5A Environmental `services, A Perennial Company, 3 2015 Historic Resource Report: 807-813 Harvard Boulevard, Los Angeles. Scientific Resource Surveys, Inc. On file at the South Central Coastal Information Center, California State University, Fullerton. 2015 Exploring a Traditional Rock Cairn: Test Excavation at CA-SDI-13/RBLI-26: The Rincon Indian Reservation, San Diego County, California. Scientific Resource Surveys, Inc. 2014 Archaeological Monitoring Results: The New Los Angeles Federal Courthouse. Scientific Resource Surveys, Inc. On file at the South Central Coastal Information Center, California State University, Fullerton.
2012 Bolsa Chica Archaeological Project Volume 7, Technological Analysis of Stone Tools, Lithic Technology at Bolsa Chica: Reduction Maintenance and Experimentation. Scientific Resource Surveys, Inc.

Presentations
2017 "Repair and Replace: Lithic Production Behavior as Indicated by the Debitage Assemblage from CA-MRP-283 the Hackney Site." Presented at the Society for California Archaeology Annual Meeting, Fish Camp, California.
2016 "Bones, Stones, and Shell at Bolsa Chica: A Ceremonial Relationship?" Presented at the Society for California Archaeology Annual Meeting, Ontario, California. 2016 "Markers of Time: Exploring Transitions in the Bolsa Chica Assemblage." Presented at the Society for California Archaeology Annual Meeting, Ontario, California. 2016 "Dating Duress: Understanding Prehistoric Climate Change at Bolsa Chica." Presented at the Society for California Archaeology Annual Meeting, Ontario, California. 2014 "New Discoveries from an Old Collection: Comparing Recently Identified OGR Beads to Those Previously Analyzed from the Encino Village Site." Presented at the Society for California Archaeology Annual Meeting, Visalia, California.
2012 Bolsa Chica Archaeology: Part Seven: Culture and Chronology. Lithic demonstration of experimental manufacturing techniques at the April meeting of The Pacific Coast Archaeological Society, Irvine, California.
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APPENDIX B
Site Record Form Update
(Deleted for Public Review; Bound Separately)
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APPENDIX C
Archaeological Records Search Results
(Deleted for Public Review; Bound Separately)
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APPENDIX D
NAHC Sacred Lands File Search Results
(Deleted for Public Review; Bound Separately)
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APPENDIX E
Confidential Maps
(Deleted for Public Review; Bound Separately)
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Appendix D
Preliminary Geotechnical Interpretive
Report
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PRELIMINARY GEOTECHNICAL

INTERPRETIVE REPORT

PROPOSED VISTA PROJECT

SOUTH SIDE OF WEST BOBIER DRIVE

EAST OF SPORTS PARK WAY

OCEANSIDE

SAN DIEGO COUNTY, CALIFORNIA
PROJECT NO. 23185-10
APRIL 25, 2024

CW SOILS
23251 Kent Court
Murrieta, CA 92562
951-304-3935
° cwsoils.com
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April 25, 2024
Mr. Michael Schweitzer. P.E.

SWS ENGINEERING, INC.
1635 Lake San Marcos Drive. Suite 200
San Marcos. CA 92078
Project No. 23185-10
Subject: Preliminary Geotechnical Interpretive Report, Vista Project, South side of West Bobier Drive and East of Sports Park Way, Oceanside, San Diego County, California In accordance with your request. CW Soils is pleased to present our preliminary geotechnical interpretive report for the Vista Project. located on the south side of West Bobier Drive and east of Sports Park Way, Oceanside.

San Diego County. California. Our services were completed in accordance with the scope of work described in our proposals. dated December 7.2023 and March 27, 2024. The purpose of our work was to evaluate the nature, distribution. and engineering properties of the geologic formations underlying the site with respect to the proposed improvements.

CW Soils appreciates the opportunity to offer our services on this project. If we can be of further assistance, please do not hesitate to contact the undersigned at your convenience.

Respectfully submitted.

CW Soils
Chad E. Welke. PG, CEG, PE
Principal Geologist/Engineer
Distribution: (1) Addressee (email)
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TABLE OF CONTENTS
INTRODUCTION 1
SITE DESCRIPTION 1
PROPOSED DEVELOPMENT 1
FIELD EXPLORATION AND LABORATORY TESTING 1
Field Exploration 1
Laboratory Testing 3
FINDINGS 3
Regional Geology 3
Local Geology 3
Aerial Photographs 5
Faulting 5
CONCLUSIONS AND RECOMMENDATIONS 5
General 5
Earthwork 5
Grading Operations 5
Clearing and Grubbing 6
Excavation Characteristics 6
Groundwater 6
Ground Preparation 6
Oversize Rock 6
Compacted Fi11 Placement 7
Import Soils 7
Fill Slopes 7
Cut Slopes 7
Temporary Backcuts 7
Geotechnical Observations 7
Post Grading Considerations 8
Slope Landscaping and Maintenance 8
Site Drainage 8
Utility Trenches 8
SEISMIC DESIGN PARAMETERS 8
Ground Motions 8
Liquefaction and Lateral Spreading 9
PRELIMINARY FOUNDATION DESIGN RECOMMENDATIONS 10
General 10
Allowable Bearing Values 10
Settlement 10
Lateral Resistance 10
Expansive Soil Considerations 10
Low Expansion Potential (Expansion Index of 21 to 50) 11 Conventional Footings 11
Building Floor Slabs 11
Post Tensioned Slab/Foundation Design Recommendations 12 Structural Setbacks and Building Clearance 13
Foundation Observations 13
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Corrosivity 14
RETAINING WALLS 15
Active and At -Rest Earth Pressures 15
Subdrain System 15
Temporary Excavations 16
Retaining Wall Backfill 16
EXTERIOR CONCRETE 16
Sub grade Preparation 16
Exterior Flatwork Design 16
PRELIMINARY PAVEMENT DESIGN 17
GRADING PLAN REVIEW AND CONSTRUCTION SERVICES 18
REPORT LIMITATIONS 19
Attachments:

Figure 1 — Vicinity Map
Figure 2 — Regional Geologic Map
APPENDIX A — References
APPENDIX B — Field Exploration
APPENDIX C — Laboratory Analysis
APPENDIX D — Seismicity
APPENDIX E — Pavement Design Calculations
APPENDIX F — General Earthwork and Grading Specifications Plate 1 — Geotechnical Map
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INTRODUCTION
This report prepared by CW Soils, presents the preliminary interpretive geotechnical evaluation for the proposed improvements. The purpose of our work was to evaluate the nature, distribution, and engineering properties of the geologic formations underlying the site with respect to the proposed improvements. Furthermore, we have included grading and foundation design recommendations based on the information you provided.

SITE DESCRIPTION
The site is located on the south side of West Bobier Drive and east of Sports Park Way, Oceanside, San Diego County, California. The subject property is surrounded by undeveloped land and scattered residential properties.

The general location of the subject property is illustrated on Figure 1 — Vicinity Map.

The subject property consists of undeveloped land with relatively flat to slightly hilly terrain. Topographic relief at the subject property is low to moderate. Vegetation at the site includes dense amounts of annual weeds/grasses along with a few trees and bushes.

PROPOSED DEVELOPMENT
Based on our understanding of the proposed project, will include three main buildings consisting of 14 units along with 3 ADU buildings consisting of 6 units and a private streets. The proposed site improvement are anticipated to consist of wood, concrete, or steel framed one- and/or two-story structures utilizing slab on grade construction with associated driveways, landscape areas, and utilities.

FIELD EXPLORATION AND LABORATORY TESTING
Field Exploration
Subsurface exploration at the subject property was performed on January 26, 2024 and April 11, 2024. On the first day of exploration a backhoe was mobilized to advance seven test pits throughout the project area to a maximum depth of 9 feet. On the second day of exploration a hand auger was mobilized to advance one boring within the project area to a maximum depth of 4 feet.

Classification and logging of the soils encountered during the field exploration were performed in general accordance with the Standard Practice for Description and Identification of Soils (Visual -Manual Procedure) of ASTM D 2488. Earth material descriptions may have been reconciled to reflect laboratory test results with regard to ASTM D 2487 or re-examination in the laboratory. Descriptive logs and the Log Symbols & Terms explanation sheet are presented in Appendix B.

Associated with the subsurface exploration was the collection of disturbed bulk samples and/or relatively undisturbed samples of soils for laboratory testing and analysis. The samples were placed in sealed containers and transported to the laboratory for testing and analysis. The exploratory locations and geologic conditions at the subject property are illustrated on Plate 1 — Geotechnical Map. 08/11/2026
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REFERENCE: Google Earth (Version 7.1.5.1557) [Software]. Mountain View, CA: Google Inc. (2015).

Approximate Site Location

VICINTY MAP
23185-10
FIGURE 1
tits/"I "I /LULb
1-'112
"Z OT bib

Laboratory Testing
Maximum dry density/optimum moisture content, expansion potential, pH, resistivity, sulfate content, and chloride content were determined for selected samples of soils, considered representative of those noted during the field exploration. The laboratory test results are reflected throughout the Conclusions and Recommendations of this report. Summaries of the test results and brief descriptions of laboratory test criteria are presented in Appendix C.

FINDINGS
Regional Geology
Regionally, the project is located in the Peninsular Ranges Geomorphic Province of California. The Peninsular Ranges are characterized by northwest trending sediment filled elongated valleys divided by steep mountain ranges. Associated with and subparallel to the northwest trending San Andreas Fault, are the San Jacinto Fault, Newport -Inglewood Fault, and the Whittier -Elsinore Fault zones. The northwest trend of the province has played a major role in shaping the dominant structural geologic features in the region as well. The Perris Block forms the eastern boundary of the Elsinore Fault, while the west side is comprised of the Santa Ana Mountains. The Perris Block is in turn bounded to the east by the San Jacinto Fault. The Peninsular Ranges Province and the Transverse Range Province are separated by the northern perimeter of the Los Angeles basin, which is formed by a northerly dipping blind thrust fault.

The low lying areas within the Peninsular Ranges Province are principally made up of Tertiary and Quaternary non -marine alluvial sediments consisting of alluvial deposits, sandstones, claystones, siltstones, conglomerates, and occasional volcanic units. The mountainous regions are primarily made up of Pre -Cretaceous, metasedimentary, and metavolcanic rocks along with Cretaceous plutonic rocks of the Southern California Batholith. A map illustrating the regional geology is presented on Figure 2 — Regional Geologic Map.

Local Geology
The most relevant local geologic units expected to be present at the site are summarized in this section. A general description of the dominant soils that form the geologic units is provided below:
• Topsoil: Topsoil was encountered to a maximum depth of 2 to 3 feet. These earth materials consist predominately of dark brown, clayey sand. These soils were generally noted to be in a moist to very moist, loose to medium dense state.
• Cretaceous Tonalite (map symbol Kt): Cretaceous age plutonic rock consisting of tonalite was mapped throughout the site. The tonalite was observed to be light grayish brown, slightly moist to moist, and in a moderately hard to very hard state. Typically, the upper 1 to 3 feet of this unit is more weathered and not as hard.

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Reference: Kennedy, M.P., et all, 2007, Geologic Map of the Oceanside 30' x 60' Quadrangle, California, U.S. Geological Survey, Department of Earth Sciences, University of California, Riverside.

REGIONAL GEOLOGIC MAP
23185-10
1:100,000
FIGURE 1
UtS/ "I "I /ZULb
4 OT bib

Aerial Photographs
A review of aerial photographs was performed during our geotechnical evaluation. No strong geomorphic expressions suggestive of recent faulting, such as linear topography, offset streams/drainage courses, lines of natural springs, or fault scarps, were interpreted to project through the proposed project area during our review of the aerial photographs of the subject property. While conducting our interpretive analysis of the site, no geomorphic evidence of recently active landsliding was found. Aerial photographs from different time periods and various scales that were utilized in our geomorphic interpretations include the following from Google Earth dated December 1985, May 1994, May 2002, January 2006, June 2009, November 2013, October 2016, August 2019, and June 2023.

Faulting
Significant ground shaking will likely impact the site within the design life of the proposed project, due to the project being located in a seismically active region. The geologic structure of the entire southern California area is dominated by northwest -trending faults associated with the San Andreas Fault system. The San Andreas Fault system accommodates for most of the right lateral movement associated with the relative motion between the Pacific and North American tectonic plates.

The subject property is not located within an Alquist-Priolo Fault Rupture Hazard Study Zone, established by the State of California to restrict the construction of habitable structures across identifiable traces of known active faults. No active faults are known to project through the proposed project. As defined by the State of California, an active fault has undergone surface displacement within the past 11,700 years or during the Holocene epoch.

The nearest known "active faults" are part of the Elsinore system less than —26.6 kilometers distant capable of producing horizontal ground accelerations of —7.6 g. A list of faults near the site are included in Appendix D.

CONCLUSIONS AND RECOMMENDATIONS
General
From a geotechnical point of view, the subject property is considered suitable for the proposed improvements, provided the design information and conclusions and recommendations herein are incorporated into the plans and are implemented during construction.

Earthwork
Grading Operations
Grading operations are subject to the provisions of the 2022 California Building Code (CBC), including Appendix J Grading, as well as all applicable grading codes and requirements of the appropriate reviewing agency. Grading operations should also be conducted in accordance with applicable requirements of our General Earthwork and Grading Specifications within the final appendix of this report, unless more conservative recommendations are provided herein.

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Clearing and Grubbing
Areas undergoing grading operations should be stripped of vegetation including trees, grasses, weeds, brush, shrubs, or any other debris and properly disposed of offsite. Laborers should be employed to remove roots, branches, or other deleterious materials during grading operations.

CW Soils should be notified in a timely manner in order to provide observations during Clearing and Grubbing operations. Any buried foundations or unanticipated conditions should be brought to our immediate attention to consider whether adjustments are necessary.

Excavation Characteristics
Based on our experience with similar projects in similar settings, the near surface soils, may be readily excavated with conventional earth moving equipment appropriately selected for the task to be performed.

The amount of excavation difficulty is often a function of the degree of weathering, type of excavation, rock lithology, and amount of fracturing within the bedrock. In general, bedrock becomes harder and more difficult to excavate with increasing depth. Very hard boulders or concretions will likely be encountered at random locations within the tonalite bedrock. The 7 exploratory test pits were excavated with a Catt 416E backhoe with an 18 -inch bucket to an average depth of 8 feet below existing grade.

Practical refusal (slow to minimal excavation progress) was encountered at depths between 7 to 9 feet.

Groundwater
Groundwater was not observed during the field exploration conducted to a maximum depth of 9 feet in test pit TP-3 and TP-7.

Ground Preparation
In areas to receive compacted fill, the removal of low density, compressible soils, such as topsoil/colluvial materials and any undocumented artificial fill, should continue until firm competent bedrock is encountered. Removal excavations should be verified by the project engineer, geologist or their representative. Prior to placing compacted fills, the exposed bottom should be scarified to a depth of 6 inches or more, watered or air dried as necessary to achieve near optimum moisture content and then compacted to a minimum of 90 percent of the maximum dry density as determined by ASTM D1557-12.

Remedial grading should extend horizontally beyond the perimeter of the proposed structure a distance equal to the depth of compacted fill below the proposed footing or a minimum of 5 feet, whichever is greater. The anticipated removal depths are shown on Plate 1 — Geotechnical Map. In general the anticipated removal depths should vary from 2 to 3 feet below existing grade.

Oversize Rock
Oversize rock (i.e., rock exceeding a maximum dimension of 12 inches) is expected to be encountered during grading. Oversize rock that is encountered should be disposed of offsite, dispersed throughout the site at the surface of natural grades, or stockpiled and crushed for future use. The disposal of oversize rock is discussed in greater detail in the last appendix of this report, General Earthwork and Grading Specifications.

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Compacted Fill Placement
Well mixed soils should be placed in 6 to 8 inch maximum (uncompacted) lifts, watered or air dried as necessary to achieve uniform near optimum moisture content and then compacted to a minimum of 90 percent of the maximum dry density as determined by ASTM D1557-12.

Import Soils
If needed to achieve final design grades, all potential import materials should be non -expansive, free of deleterious/oversize materials, and approved by the project soils engineering consultant prior to delivery onsite.

Fill Slopes
Fill slopes higher than 5 feet and steeper than 5:1 (h:v) require a keyway at the toe. Keyways should be excavated 2 feet into bedrock, as measured on the downhill side and be a minimum of 10 feet wide.

Backcuts for keyway excavations should be cut no steeper than 1:1 or as recommended by the soils engineer or engineering geologist. As compacted fill is placed, proper benching into bedrock should be maintained.

Cut Slopes
Cut slopes no steeper than 2:1 (h:v) into bedrock are expected to be stable. Cut slopes should be observed by the engineering geologist or his representative during grading operations.

Temporary Backcuts
With regard to excavation safety, it is the responsibility of the grading contractor to follow all Cal -OSHA requirements. Adequate slope stability to protect adjacent developments must be maintained, temporary backcuts for canyon removals, stabilization fills, and/or keyways may be needed. It is imperative that grading schedules minimize the exposure time of the unsupported excavations. Temporary backcuts should be observed by the engineering geologist or his representative during grading/construction operations.

Geotechnical Observations
Clearing operations, removal of unsuitable materials, and general grading procedures should be observed by the project soils consultant or his representative. Compacted fill should not be placed without prior bottom observations being conducted by the soils consultant or his representative to verify the adequacy of the removals.

The project soils consultant or his representative should be present to observe grading operations and to check that the minimum compaction requirements are being obtained. In addition, verification of compliance with the other grading recommendations presented herein should be provided concurrently.

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Post Grading Considerations
Slope Landscaping and Maintenance
Provided all drainage provisions are properly constructed and maintained, the gross stability of graded slopes should not be adversely affected. However, satisfactory slope and building pad drainage is essential for the long term performance of the site. Concentrated drainage should not be allowed to flow uncontrolled over any descending slope. As recommended by the project landscape architect, engineered slopes should be landscaped with deep rooted, drought tolerant maintenance free plant species.

Site Drainage
Maintaining control over drainage throughout the site is important for the long term performance of the proposed improvements. We recommend roof gutters or equivalent roof collection system for proposed structures. Pad and roof drainage should be routed in non -erosive drainage devices to driveways, adjacent streets, storm -drain facilities, or other locations approved by the building official. Drainage should not be allowed to pond on the building pad or near any foundations. Planters located within retaining wall backfill should be sealed to prevent moisture intrusion into the backfill. Planters located next to structures should be sealed to the depth of the footings. Drainage control devices require periodic cleaning, testing and maintenance to remain effective.

Building pad drainage should be designed to meet the minimum gradient requirements of the CBC, to divert water away from foundations.

Utility Trenches
All utility trench backfill should be compacted at near optimum moisture to a minimum of 90 percent of the maximum dry density as determined by ASTM D1557-12. Trench backfill should be placed in approximately 6 to 8 inch maximum loose lifts and then mechanically compacted with a hydro -hammer, a sheepsfoot, pneumatic tampers, or similar equipment. Within pavement areas, the upper 6 inches of subgrade materials for utility trench backfill should be compacted to 95 percent of the maximum dry density determined by ASTM D1557-12. The utility trench backfill should be observed and tested by the project soils engineer or their representative to verify that the minimum compaction requirements have been obtained.

Where utility trenches undercut perimeter foundations, all utility trenches should be backfilled with compacted fill, lean concrete, or concrete slurry. When practical, interior or exterior utility trenches that run parallel to structure footings should not be located within a 1:1 (h:v) plane projected downward from the outside bottom edge of the footing.

SEISMIC DESIGN PARAMETERS
Ground Motions
To resist the effects of design level seismic ground motions in order to prevent collapse (1% probability of collapse in 50 years), structures are required to be designed and constructed in accordance with the 2022 California Building Code Section 1613. The design is reliant on the site class, risk category (I, II, III, or IV), and mapped spectral accelerations for short periods (Ss) and a 1 -second period (Si).

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Based on data and maps jointly compiled by the United States Geological Survey (USGS) and the California Geological Survey (CGS), spectral accelerations for the subject property were generated via software applications utilizing the USGS US Seismic Design Maps. The data summarized in the following table is based on the Maximum Considered Earthquake Geometric Mean (MCEG) with 5% damped ground motions having a 2% probability of being exceeded in 50 years (2,475 -year return period).

The seismic design parameters were determined by a combination of the site class, mapped spectral accelerations, on site soil/rock conditions, and risk category. The compilation of seismic design parameters found below are considered appropriate for implementation during structural design. Summaries of the Seismic Hazard Deaggregation and site data is included in Appendix D.

PARAMETER
FACTOR
Site Location
Latitude: 33.2207
Longitude: -117.2555
Site Class (1613.2.2 of 2022 CBC, Chapter 20 of ASCE 7) B
Mapped Spectral Accelerations for short periods
Ss (g)

0.92 Mapped Spectral Accelerations for 1 -Second Period Si (g)

0.34 Maximum Considered Earthquake Spectral Response
Acceleration for Short Periods
S. (g)

0.828
Maximum Considered Earthquake Spectral Response
Acceleration for 1 -Second Period
S. (g)

0.272
Design Spectral Response Acceleration for Short Periods SDS (g)

0.552
Design Spectral Response Acceleration for 1 -Second Period SDI (g)

0.181
Seismic Design Category
SDC
D
Importance Factor Based on Risk Category
II
Probabilistic seismic hazard assessment, and in some cases deterministic seismic hazard assessments, for the site were conducted in accordance with the 2022 CBC, Section 1803.5.11 and 1803.5.12. The probabilistic seismic hazard maps and data files were jointly prepared by the United States Geological Survey (USGS) and the California Geological Survey (CGS). Actual ground shaking intensities at the subject property may be substantially higher or lower based on complex variables such as the near source directivity effects, depth and consistency of soils, topography, geologic structure, direction of fault rupture, seismic wave reflection, refraction, and attenuation rates. The mean peak ground acceleration was calculated to be 0.358g.

Liquefaction and Lateral Spreading
The three requirements for liquefaction to occur include seismic shaking, poorly consolidated cohesionless sands, and groundwater. Liquefaction results in a substantial loss of shear strength in loose, saturated, cohesionless soils subjected to earthquake induced ground shaking. Potential impacts from liquefaction include loss of bearing capacity, liquefaction related settlement, lateral movements, and surface manifestation in the form of sand boils.

The potential for design level earthquake induced liquefaction and lateral spreading to occur beneath the proposed structures is considered very low to remote due to the proposed compacted fill and shallow bedrock.

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PRELIMINARY FOUNDATION DESIGN RECOMMENDATIONS
General
Conventional shallow foundations are considered feasible for support of the proposed structures, provided grading and construction are performed in accordance with the recommendations of this report. Foundation recommendations are provided in the following sections. Graphic presentations of relevant information and recommendations may also included on Plate 1 — Geotechnical Map.

Allowable Bearing Values
An allowable bearing value of 2,000 pounds per square foot (psf) is recommended for design of 12 inch wide continuous footings founded at a minimum depth of 12 inches below the lowest adjacent final grade and 24 inch square pad footings. This value may be increased by 20 percent for each additional 1 -foot of width and/or depth to a maximum value of 2,500 psf. Recommended allowable bearing values include both dead and frequently applied live loads and may be increased by one third when designing for short duration wind or seismic forces.

Settlement
We estimate that the maximum total settlement of the footings will be less than approximately 3/4 inch, based on the anticipated loading and the settlement characteristics of the underling earth materials. Differential settlement is expected to be about %2 inch over a horizontal distance of approximately 20 feet, for an angular distortion ratio of 1:480. The majority of the settlement is anticipated to occur during construction or shortly after the initial application of loading.

The above settlement estimates are based on the assumption that the grading and construction are performed in accordance with the recommendations presented in this report. Additionally, the project soils consultant or his representative will be provided the opportunity to observe the foundation excavations.

Lateral Resistance
Passive earth pressure of 250 psf per foot of depth to a maximum value of 2,500 psf may be used to establish lateral bearing resistance for footings. A coefficient of friction of 0.30 times the dead load forces may be used between concrete and the supporting soils to determine lateral sliding resistance. When combining passive and friction for lateral resistance, the passive component should be reduced by one third. In no case shall the lateral sliding resistance exceed one-half the dead load for clay, sandy clay, sandy silty clay, silty clay, and clayey silt.

The above lateral resistance values are based on footings for an entire structure being placed directly against compacted fill or bedrock, but not both at the same time.

Expansive Soil Considerations
The preliminary laboratory test results indicate that the onsite soils exhibit an expansion potential of LOW as classified by the 2022 CBC Section 1803.53 and ASTM D4829-03.

The following recommendations should be considered the very minimum requirements, for the soils tested. It is common practice for the project architect or structural engineer to require additional slab thickness, footing sizes, and/or reinforcement.

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Low Expansion Potential (Expansion Index of 21 to 50)
Our laboratory test results indicate that the soils onsite exhibit a LOW expansion potential as classified by the 2022 CBC Section 1803.53 and ASTM D4829-03. As such, the CBC specifies that slab on grade foundations (floor slabs) resting on soils with expansion indices greater than 20, require special design considerations per the 2022 CBC Sections 1808.6.1 and 1808.6.2. The design procedures incorporate the thickness and plasticity index of the various soils within the upper 15 feet of the proposed structure. We have assumed an effective plasticity index of 12, for preliminary design purposes.

Conventional Footings
• Exterior continuous footings should be founded at the minimum depths below the lowest adjacent final grade (i.e. minimum 12 inch depth for one-story, minimum 18 inch depth for two-story, and minimum 24 inch depth for three-story construction). Interior continuous footings for one-, two-, and three- story construction may be founded at a minimum depth of 12 inches below the lowest adjacent final grade. In accordance with Table 1809.7 of the 2022 CBC, all continuous footings should have a minimum width of 12, 15, and 18 inches, for one-, two-, and three-story structures, respectively, and should be reinforced with a minimum of two (2) No. 4 bars, one (1) top and one (1) bottom. • Exterior pad footings intended to support roof overhangs, such as second story decks, patio covers and similar construction should be a minimum of 24 inches square and founded at a minimum depth of 18 inches below the lowest adjacent final grade. The pad footings should be reinforced with a minimum of No. 4 bars spaced a maximum of 18 inches on center, each way, and should be placed near the bottom -third of the footings.

Building Floor Slabs
• Building floor slabs should be a minimum of 4 inches thick. All floor slabs should be reinforced with a minimum of No. 3 bars spaced a maximum of 18 inches on center, each way, supported by concrete chairs or bricks to ensure desired mid -depth placement. Based on an assumed effective plasticity index of 12, the project architect or structural engineer should evaluate minimum floor slab thickness and reinforcement in accordance with 2022 CBC Section 1808.6.2. • Building floor slabs with moisture sensitive or occupied areas, should be underlain by a minimum 10 - mil thick moisture barrier to help reduce the upward migration of moisture from the underlying soils.

The moisture barrier should be properly installed using the guidelines of ACI publication 318-05 and meet the performance standards of ASTM E 1745 Class A material. Prior to placing concrete, it is the responsibility of the contractor to ensure that the moisture barrier is properly placed and free of openings, rips, or punctures. As an option for additional moisture protection and foundation strength, higher strength concrete, such as a minimum compressive strength of 5,000 pounds per square inch (psi) in 28 -days may be used. In addition, a capillary break/vapor retarder for concrete slabs should be provided in accordance with CALGreen. Ultimately, the design of the moisture barrier system along with recommendations for concrete placement and curing are the purview of the foundation engineer, factoring in the project conditions provided by the architect and owner. • Garage floor slabs should be a minimum of 4 inches thick and should be reinforced in a similar manner as living area floor slabs. Garage floor slabs should be placed separately from adjacent wall footings with a positive separation maintained with % inch minimum felt expansion joint materials and quartered with weakened plane joints. A 12 inch wide turn down founded at the same depth as adjacent April 25, 2024
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footings should be provided across garage entrances. The turn down should be reinforced with a minimum of two (2) No. 4 bars, one (1) top and one (1) bottom. • Prior to placing concrete, the subgrade soils below all floor slabs should be pre -watered to achieve a moisture content that is at least equal or slightly greater than optimum moisture content. The moisture content should penetrate a minimum depth of 6 inches into the subgrade soils. The pre -watering should be verified by CW Soils during construction.

Post Tensioned Slab/Foundation Design Recommendations
In lieu of the proceeding foundation recommendations, post tensioned slabs may be used for the proposed structures. Post tension foundations are generally considered to be a better foundation system, but may be slightly higher in overall cost. The foundation engineer may design the post tensioned foundation system using the following Post Tensioned Foundation Slab Design table. These parameters have been provided in general accordance with Post Tensioned Design. Alternate designs addressing the effects of expansive soils are allowed per 2022 CBC Section 1808.6.2. When utilizing these parameters, the foundation engineer should design the foundation system in accordance with the allowable deflection criteria of applicable codes.

It should be noted that the post tensioned design methodology is partially based on the assumption that soils moisture changes around and underneath post tensioned slabs, are only influenced by climate conditions. With regard to expansive soils, moisture variations below slabs are the major factor in foundation damage. However, the design methodology does not take into account presaturation, owner irrigation, or other non -climate related influences on the moisture content of the subgrade soils. In recognition of these realities, we modified the soils parameters obtained from this methodology to help account for reasonable irrigation practices. Additionally, the slab subgrades should be presoaked to a depth of 12 inches and maintained at above optimum moisture until placing concrete. Furthermore, prior to placing concrete, the subgrade soils below all floor slabs and perimeter footings should be presoaked to achieve moisture contents at least 1.0, 1.1, 1.2, and 1.3 times optimum to depths of 6, 12, 18, and 24 inches for Low, Medium, High, and Very High expansion potential soils, respectively. The moisture content should penetrate to a minimum depth of 24 inches into the subgrade soils. The pre -watering should be verified and tested by CW Soils.

Ponding water near the foundation can significantly change the moisture content of the soils below the foundation, causing excessive foundation movement and detrimental effects. Our recommendations do not account for excessive irrigation and/or incorrect landscape designs. To prevent moisture infiltration below the foundation, planters placed adjacent to the foundation should be designed with an effective drainage system or liners. Some lifting of the perimeter foundation should be expected even with properly constructed planters.

Future owners should be informed and educated of the importance in maintaining a consistent level of moisture within the soils around structures. Potential negative consequences can result from either excessive watering or allowing expansive soils to become too dry. Expansive soils will shrink as they dry, followed by swelling during the rainy winter season or when irrigation is resumed, causing distress to site improvements.

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Post Tensioned Foundation Slab Design
PARAMETER 1
VALUE
Expansion Index
Low'
Percent Finer than 0.002 mm in the
< 20 percent (assumed)
Fraction Passing the No. 200 Sieve
Clay Mineral Type
Montmorillonite (assumed)
Thomthwaite Moisture Index
-20
Depth to Constant Soil Suction
7 feet
Constant Soil Suction
P.F. 3.6
Moisture Velocity

0.7 inch/month
Center Lift Edge moisture
variation distance, em
Center lift, ym

5.5 feet

2.0 inches
Edge Lift Edge moisture
variation distance, em
Edge lift, ym

3.0 feet

0.8 inches
Soluble Sulfate Content for Design of
Concrete Mixtures in Contact with Soils
Negligible
Modulus of Subgrade Reaction, k
(assuming presaturation as indicated
below)
200 pci
Minimum Perimeter Foundation
12 Embedment
Perimeter Foundation Reinforcement
--
Under Slab Moisture Barrier and Sand
Layer
10 -mil thick moisture barrier meeting the requirements of a ASTM E 1745 Class A material

1. Assumed for design purposes or obtained by laboratory testing.

2. Recommendations for foundation reinforcement are ultimately the purview of the foundation/structural engineer based upon the soils criteria presented in this report and structural engineering considerations.

Structural Setbacks and Building Clearance
Structural setbacks are required by the 2022 California Building Code (CBC). No additional structural setbacks are required due to geologic or soils conditions within the site. Improvements constructed near natural or properly compacted engineered slopes can, over time, be affected by natural processes including gravity forces, shrink/swell processes, weathering, and long term secondary settlement. As a result, the CBC requires that structures be setback or footings deepened to resist the influence of these processes.

For structures that are planned near ascending and descending slopes, the footings should be embedded to satisfy the requirements presented in the 2022 CBC, Section 1808.7. Foundations are required to be founded in accordance with the Foundation Clearances from Slopes Detail (CBC, 2022), which is illustrated in the last Appendix of this report.

When determining the required clearance from ascending slopes with a retaining wall at the toe, the height of the slope shall be measured from the top of the wall to the top of the slope.

Foundation Observations
Prior to the placement of forms, concrete, or steel, all foundation excavations should be observed by the geologist, engineer, or his representative to verify that they have been excavated into competent bearing materials, in April 25, 2024
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accordance with the 2022 CBC. The foundations should be excavated per the approved plans, moistened, cleaned of all loose materials, trimmed neat, level, and square. Moisture softened soils should be removed prior to steel or concrete placement. Soils from foundation excavations should be removed from slab on grade areas, unless they have been properly compacted and tested.

Corrosivity
Corrosion is defined by the National Association of Corrosion Engineers (NACE) as "a deterioration of a substance or its properties because of a reaction with its environment." From a soils engineering point of view, the "substances" are the reinforced concrete foundations or buried metallic elements (not surrounded by concrete) and the "environment" is the prevailing soils in contact with them. Many factors can contribute to corrosivity, including the presence of chlorides, sulfates, salts, organic materials, different oxygen levels, poor drainage, varying soils consistencies, and moisture content. It is not considered practical or realistic to test for all of the factors which may contribute to corrosivity.

The level of chlorides considered to be significantly detrimental to concrete is based upon the industry recognized Caltrans standard "Bridge Design Specifications". Under subsection 8.22.1 of that document, Caltrans established that "Corrosive water or soil contains more than 500 parts per million (ppm) of chlorides". Based on limited testing, the onsite soils tested have chloride contents less than 500 ppm. Therefore, specific requirements resulting from elevated chloride contents are not required.

When the soluble sulfate content of soils exceeds 0.1 percent by weight, specific guidelines for concrete mix design are provided in the 2022 CBC Section 1904 and in ACI 318, Section 4.3 Table 4.3.1. Based on limited testing, the onsite soils are classified as having a negligible (less than 0.10 % by weight) sulfate exposure condition, in accordance with Table 4.3.1. Therefore, structural concrete in contact with onsite soils should utilize Type I or II.

The onsite soils in contact with buried steel should be considered mildly corrosive (2,000 to 10,000 Ohms -cm) based on our laboratory testing of resistivity. Additionally, pH values below 9.7 are recognized as being corrosive to most common metallic components including, copper, steel, iron, and aluminum. The pH values for the soils tested were lower than 9.7. Therefore, any steel or metallic materials that are exposed to the soils should be encased in concrete or other remedies applied to provide corrosion protection.

For structures utilizing post tensioned systems, the post tensioning cables should be encased in concrete and/or encapsulated in accordance with the Post Tensioning Institute Guide Specifications. If post tensioning cable end plate anchors and nuts are exposed, they should also be protected. If the anchor plates and nuts are recessed into the edge of the concrete slab, the recess should be filled in with a non -shrink, non -porous, moisture -insensitive epoxy grout so that the anchorage assembly and the end of the cable are completely encased and isolated from the soils. A standard non -shrink, non-metallic cementatious grout may be used only when the post tension anchoring assembly is polyethylene encapsulated, similar to that offered by Hayes Industries, LTD or O' Strand, Inc.

It should be noted that CW Soils are not corrosion engineers and the test results for corrosivity are based on limited samples thought to be representative. The grading operations may blend various soils together and/or unveil soils with higher corrosive properties. This blending or imported material could alter and increase the detrimental properties of the onsite soils. Thus, it is important that additional testing near final grades for chlorides and sulfates along with testing for pH and resistivity be performed upon completion of the grading operations.

Laboratory test results are presented in Appendix C.

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RETAINING WALLS
Active and At -Rest Earth Pressures
Retaining wall foundations may be designed in accordance with the recommendations provided in the Preliminary Foundation Design Recommendation section of this report. For design of retaining walls up to 6 feet high, the table below provides the minimum recommended equivalent fluid pressures.

The active earth pressure should be used for design of unrestrained retaining walls, which are free to tilt slightly.

The at -rest earth pressure should be used for design of retaining walls that are restrained at the top, such as basement walls, curved walls with no joints, or walls restrained at corners. For curved walls, active pressure may be used if tilting is acceptable and construction joints are provided at each angle point and at a minimum of 15 foot intervals along the curved segments.

MINIMUM STATIC EQUIVALENT FLUID PRESSURE (pct.)

PRESSURE TYPE

BACKSLOPE CONDITION
LEVEL
2:1 (h:v) .

Active Earth Pressure
43 63
At -Rest Earth Pressure
60 95
Hydrostatic pressure behind the retaining walls has not been taken into account when calculating the parameters provided. Therefore, the subdrain system is a very important part of the design. If additional loads are being applied within a 1:1 plane projected up from the heel of the retaining wall footing, due to surcharge loads imposed by other nearby walls, structures, vehicles, etc., then additional pressure should be added to the above earth pressures to account for the expected surcharge loads. In order to minimize surcharge loads and the settlement potential of nearby structures, the footings for the structure can be deepened below the 1:1 plane projected up from the heel of the retaining wall footing.

Upon request and under a separate scope of work, more detailed analyses can be provided to address retaining wall designs with regard to value engineering, stepped retaining walls, actual retaining wall heights, actual backfill inclinations, specific backfill materials, higher retaining walls requiring earthquake design motions, etc.

Subdrain System
To prevent the buildup of hydrostatic pressure behind the proposed retaining walls, we recommend a perforated pipe and gravel subdrain system be provided behind all retaining walls. The subdrain system should consist of 4 inch minimum diameter Schedule 40 PVC or ABS SDR-35 perforated pipe, placed with the perforations facing down. The pipe should be surrounded by a minimum of 1 cubic foot per foot of 3/4- or 11 inch open graded gravel wrapped in Mirafi 140N or equivalent filter fabric, to prevent infiltration of fines and subsequent clogging of the subdrain system.

In addition, the retaining walls should be adequately coated on the backfilled side of the walls with a proven waterproofing compound by an experienced professional to inhibit infiltration of moisture through the walls.

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Temporary Excavations
All excavations should be made in accordance with Cal -OSHA requirements. CW Soils is not responsible for job site safety.

Retaining Wall Backfill
Retaining wall backfill materials should be approved by the soils engineer or his representative prior to placement as compacted fill. Retaining wall backfill should be placed in lifts no greater than 6 to 8 inches, watered or air dried as necessary to achieve near optimum moisture contents. All retaining wall backfill should be compacted to a minimum of 90 percent of the maximum dry density as determined by ASTM D1557. When practical, retaining wall backfill should be capped with a paved surface drain.

EXTERIOR CONCRETE
Subgrade Preparation
Subgrade soils underlying concrete flatwork should be compacted at near optimum moisture to a minimum of 90 percent of the maximum dry density as determined by ASTM test method D1557-12. Prior to placing concrete, the subgrade soils should be moistened to at least optimum or slightly above optimum moisture content (see table below). Pre -watering of the soils prior to placing concrete will promote uniform curing of the concrete and minimize the development of shrinkage cracks. The higher the expansion potential of the onsite soils the longer it will take to achieve the recommended presaturation. Therefore, the procedure and timing should be planned in advance.

Exterior Flatwork Design
Cracking within concrete flatwork is often a result of factors such as the use of too high of a water to cement ratio and/or inadequate steps taken to prevent moisture loss during the curing of the concrete. However, minor cracking within concrete flatwork is normal and should be expected. It should be noted that the reduction of slab cracking is often a function of proper slab design, concrete mix design, placement, curing, and finishing practices. We recommend the adherence to the guidelines of the American Concrete Institute (ACI).

When placed over expansive soils, exterior concrete elements are susceptible to lifting and cracking. When this occurs with highly expansive soils, the detrimental impacts can be significant and may necessitate the removal and replacement of the affected improvements. In order to reduce the potential for unsightly cracking, we suggest a combination of presaturation of the subgrade soils, reinforcement, restraint, and a layer of granular materials.

Although these measures may not completely eliminate distress to concrete improvements, the application of these measures can significantly reduce the distress caused by expansive soils. The degree and extent the measures recommended in the following table are applied depend on:
• The expansion potential of the subgrade soils.
• The practicality of implementing the measures (such as presaturation). • The benefits verse the economics of the measures.

The project owner should perform a cost/benefit analysis on the factors to determine the extent the measures will be applied to each project. The expansive potential of the onsite soils should be considered LOW.

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EXTERIOR CONCRETE FLATWORK

CONSTRUCTION
DESIGN

EXPANSION INDEX

VERY LOW
LOW
MEDIUM
HIGH

VERY HIGH
Slab Thickness, Minimum

3.5 inches
4 inches
4 inches
4 inches

4.5 inches
Subbase, Gravel Layer
NA
NA
Optional
3 inches
4 inches
Presaturation, Relative to
Optimum Moisture Content
Pre -wet
NA
Optimum

1.1 x Optimum
12 inches Deep

1.2 x Optimum
18 inches Deep

1.3 x Optimum
24 inches Deep
6 inches Deep
Joint, Maximum Spacing,
(joint to extend '/4 slab)
10 feet or less
10 feet or less
8 feet or less
6 feet or less
6 feet or less
Reinforcement, Mid -Depth
NA
NA
Optional
(WWF 6 x 6
W1.4 x W1.4)
No. 3 Rebar
24" On Center
Both Ways
No. 3 Rebar
24" On Center
Both Ways
Restraint, Slip Dowels
Mid -Depth
NA
NA
Optional
Across Cold
Joints
Across Cold
Joints
The use of a granular layer for exterior slabs is primarily intended to facilitate presaturation and subsequent construction operations by providing a working surface over the saturated soils and to help retain the moisture.

Where these factors are insignificant, the layer may be omitted.

PRELIMINARY PAVEMENT DESIGN
Soils thought to be representative indicate an assumed R -value of 12 (Geocon, 2021) may be used for preliminary pavement design. Calculated in accordance with the State of California design procedures (maximum design R - value of 50) using assumed Traffic Indices, the following table summarizes the minimum recommended asphalt concrete pavement sections. Final pavement design should be based on sampling and testing of post grading conditions. Alternative, but equivalent pavement sections and calculation sheets have been provided within the appendices of this report.

ASPHALT CONCRETE PAVEMENT DESIGN

PARAMETERS

AUTO PARKING

AUTO DRIVES

ENTRANCES/TRUCK
DRIVES
Assumed Traffic Index

5.0 6.0

7.0 Preliminary Design R -Value
12 12
12 AC Thickness (inches)
3 3
3'/2
AB Thickness (inches)

8.5 12

14.5 Note:

AC —Asphalt Concrete
AB — Aggregate Base
The following table includes the minimum recommended Portland cement concrete pavement design sections calculated using the guidelines of the State of California design procedures.

PORTLAND CEMENT CONCRETE PAVEMENT DESIGN
Street Type
Preliminary
Design R -Value
Traffic Index
Pavement Section (inches)

ENTRANCES/TRUCK DRIVES
12 6.0
6 PCC over 9 AB
Note: PCC—Portland Cement Concrete
AB — Aggregate Base
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The minimum requirements for the Portland cement concrete shall be a six sack mix and 3,500 pounds per square inch at 28 days.

The subgrade soils immediately below the aggregate base (base) should be compacted to a minimum of 95 percent of the maximum dry density as determined by ASTM D1557 to a minimum depth of 12 inches. Base materials should be compacted to a minimum of 95 percent of the maximum dry density as determined by ASTM D1557.

Base materials should consist of Class 2 aggregate base conforming to Section 26-1.02B of the State of California Standard Specifications or crushed aggregate base conforming to Section 200-2 of the Standard Specifications for Public Works Construction (Greenbook). Base materials should be compacted at or slightly below optimum moisture content. Asphalt concrete materials and construction operations should conform to Section 203 of the Greenbook.

GRADING PLAN REVIEW AND CONSTRUCTION SERVICES
This report has been prepared for the exclusive use of SWS and their authorized representative. It is unlikely to contain sufficient information for other parties or other uses. CW Soils should be provided the opportunity to review the final design plans and specifications prior to construction, in order to verify that the recommendations have been properly incorporated into the project plans and specifications. If CW Soils is not accorded the opportunity to review the project plans and specifications, we are not responsibility for misinterpretation of our recommendations.

We recommend that CW Soils be retained to provide soils engineering and engineering geologic services during the grading and foundation excavation phases of work, in order to allow for design changes in the event that the subsurface conditions differ from those anticipated prior to construction.

CW Soils should review any changes in the project and modify the conclusions and recommendations of this report in writing. This report along with the drawings contained within are intended for design input purposes only and are not intended to act as construction drawings or specifications. In the event that conditions during grading or construction operations appear to differ from those indicated in this report, our office should be notified immediately, as appropriate revisions may be required.

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REPORT LIMITATIONS
Our services were performed using the degree of care and skill ordinarily exercised, under similar circumstances, by reputable soils engineers and geologists, practicing at the time and location this report was prepared. No other warranty, expressed or implied, is made as to the conclusions and professional advice included in this report.

Soils vary in type, strength, and other engineering properties between points of observation and exploration.

Groundwater and moisture conditions can also vary due to natural processes or the works of man on this or adjacent properties. As a result, we do not and cannot have complete knowledge of the subsurface conditions beneath the proposed project. No practical study can completely eliminate uncertainty with regard to the anticipated geologic and soils engineering conditions in connection with a proposed project. The conclusions and recommendations within this report are based upon the findings at the points of observation and are subject to confirmation by CW Soils based on the conditions revealed during grading and construction operations.

This report was prepared with the understanding that it is the responsibility of the owner, to ensure that the conclusions and recommendations contained herein are brought to the attention of the other project consultants and are incorporated into the plans and specifications. The owners' contractor should implement the recommendations in this report and notify the owner as well as our office if they consider any of the recommendations presented herein to be unsafe or unsuitable.

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APPENDIX A

REFERENCES
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APPENDIX A
References
California Building Standards Commission, 2022, 2022 California Building Code, California Code of Regulations Title 24, Part 2, Volume 2 of 2, Based on 2018 International Building Code.

California Geological Survey, 2008, Guidelines for Evaluating and Mitigating Seismic Hazards in California, Special Publication 117A, September 11, 2008.

California Geological Survey, 2018, Earthquake Fault Zones A Guide for Government Agencies, Property Owners /Developers, and Geoscience Practitioners for Assessing Fault Rupture Hazards in California, Special Publication 42, 2018.

Geocon, 2021, Preliminary Geotechnical Investigation, Modera Melrose, Oceanside California, dated January 26, 2021.

Hart, Earl W. and Bryant, William A., 1997, Fault Rupture Hazard Zones in California, CDMG Special Publication 42, revised 2003.

Kennedy, M.P., et all, 2007, Geologic Map of the Oceanside 30' x 60' Quadrangle, California, U.S. Geological Survey, Depai lment of Earth Sciences, University of California, Riverside.

National Association of Corrosion Engineers, 1984, Corrosion Basics An Introduction, page 191.

USGS Earthquake Hazards Program, Unified Hazard Tool for Conterminous U.S. 2014 (v4.1.1) Deaggregation Program.

April 25, 2024
08/11/2026
2 CW Soils
PH2 331 of 876

APPENDIX B

FIELD EXPLORATION
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9Z0Z/ I. 1. /80
918 4° £££
Project: Vista
Project No.: 23185-10
Eq uip.: Catt 416E Backh oe (18")
Logged by: CEW
Date: 1/26/24
Sample
No.

Depth (ft)
Classificatio n
Dry Density (pcf)
Moisture (%)
Graphic Log: East Wall
Scale: 1" = 5'
Orientatio n: Northerly
Elevatio n (ft): See Plate 1
-
o -
2-8
8 - 8s
sC
-
-
-
-
A- Topsoil/"Collu vium":

Clayey SAN D; dark brown, moist, loose to medi um dense -
B - Cretaceous To nalite (Kt):

Tonalite; light grayish br ow n, slightly moist to moist, m oderately hard to hard -
C - hard to very hard
Practical Refusal (feet): 8 .5 No Grou ndwater (feet):

Boulder
Boulder
AV'
SOILS
Test Pit 1

9Z0Z/ I. 1. /80
9L8 4° 17££
Project: Vista
Project No.: 23185-10
Eq uip.: Catt 416E Backh oe (18")
Logged by: CEW
Date: 1/26/24
Sample
No.

Depth (ft)
Classificatio n
Dry Density (pcf)
Moisture (%)
Graphic Log: East Wall
Scale: 1" = 5'
Orientatio n: Northerly
Elevatio n (ft): See Plate 1
-
o -
5 - 7
SC
-
-
A - Topsoil/"Collu vium":

Clayey SAN D; dark brown, moist, loose
B - Cretaceous To nalite (Kt):

Tonalite; light grayish br ow n, slightly moist to moist, m oderately hard to hard -
C - hard to very hard
Practical Refusal (feet): 7 No Groundwater (feet):

Boulder
1J
AV'
SOILS
Test Pit 2

9Z0Z/ I. 1. /80
919 40 9££
Project: Vista
Project No.: 23185-10
Eq uip.: Catt 416E Backh oe (18 ")
Logged by: CEW
Date: 1/26/24
sample
No.

Depth (ft)
Classificatio n
Dry Density (pcf)
Moisture lei
Graphic Log: North Wall
Scale: 1" = 5'
Orientatio n: Westerly
Elevatio n (ft): See Plate 1
-
o - 2
6 - 9
SC
-
-
A - Topsoil/"Colluvium":

Clayey SAN D; dark brown, moist, loose
B - Cretaceous To nalite (Kt):

Tonalite; light grayish br ow n, slightly moist to moist, m oderately hard to hard -
C - hard to very hard
Practical Refusal (feet): 9 No Groundwater (feet):

CI
SOILS
Test Pit 3

9Z0Z/ I. 1. /80
919 40 9££
Project: Vista
Project No.: 23185-10
Eq uip.: Catt 416E Backh oe (18 ")
Logged by: CEW
Date: 1/26/24
sample
No.

Depth (ft)
Classificatio n
Dry Density (pcf)
Moisture lei
Graphic Log: North Wall
Scale: 1" = 5'
Orientatio n: Westerly
Elevatio n (ft): See Plate 1
-
o - 2
7 - S
SC
-
-
A - Topsoil/"Colluvium":

Clayey SAN D; dark brown, moist, loose to medi um dense B - Cretaceous To nalite (Kt):

Tonalite; light grayish br ow n, slightly moist to moist, m oderately hard to hard -
C - hard to very hard
Practical Refusal (feet): 8 No Groundwater (feet):

A
—
CI
SOILS
Test Pit 4

9Z0Z/ I. 1. /80
919 4° L££
Project: Vista
Project No.: 23185-10
Eq uip.: Catt 416E Backh oe (18 ")
Logged by: CEW
Date: 1/26/24
sample
No.

Depth (ft)
Classificatio n
Dry Density (pcf)
Moisture lei
Graphic Log: North Wall
Scale: 1" = 5'
Orientatio n: Westerly
Elevatio n (ft): See Plate 1
-
o - 2
6 - S
SC
-
-
A - Topsoil/"Colluvium":

Clayey SAN D; dark brown, moist, loose to medi um dense B - Cretaceous To nalite (Kt):

Tonalite; light grayish br ow n, slightly moist to moist, m oderately hard to hard -
C - hard to very hard
Practical Refusal (feet): 8 No Groundwater (feet):

Concrete
Pipe
CI
SOILS
Test Pit 5

9Z0Z/ I 1. /80
a
2 N
919 40 88£
Project: Vista
Project No.: 23185-10
Eq uip.: Catt 416E Backh oe (18 ")
Logged by: CEW
Date: 1/26/24
sample
No.

Depth (ft)
Classificatio n
Dry Density (pcf)
Moisture lei
Graphic Log: North Wall
Scale: 1" = 5'
Orientatio n: Westerly
Elevatio n (ft): See Plate 1
-
o - 2
6 - 7. 5
SC
-
-
-
A - Topsoil./"Collu vium":

Clayey SAN D; dark brown, moist, loose
B - Cretaceous To nalite (Kt):

Tonalite; light grayish br ow n, slightly moist to moist, hard C - very hard
Practical Refusal (feet): 7 .5 No Grou ndwater (feet):
-
L \
1 A
�
-
�
sue'-`
SOILS
Test Pit 6

9Z0Z/ I. 1. /80
919 40 6££
Project: Vista
Project No.: 23185-10
Eq uip.: Catt 416E Backh oe (18")
Logged by: CEW
Date: 1/26/24
Sample
No.

Depth (ft)
Classificatio n
Dry Density (pcf)
Moisture (%)
Graphic Log: East Wall
Scale: 1" = 5'
Orientatio n: Northerly
Elevatio n (ft): See Plate 1
-
o -
7 - 9
SC
-
-
A- Topsoil/"Collu vium":

Clayey SAN D; dark brown, moist, loose
B - Cretaceous To nalite (Kt):

Tonalite; light grayish br ow n, slightly moist to moist, m oderately hard to hard -
C - hard to very hard
Practical Refusal (feet): 9 No Groundwater (feet):

H
AV'
SOILS
Test Pit 7

Geotechnical Hand Auger Boring Log HA -1
Date: April 11, 2024
Project Name: Vista Page: 1 of 1
Project Number: 23185-10A
Logged By: CW
Drilling Company: NA
Type of Rig: NA
Drive Weight (lbs): NA
Drop (in): NA Hole Diameter (in): 3
Top of Hole Elevation (ft): NA
Hole Location: See Geotechnical Map
Depth (ft)
Blow Count Per
Foot
Sample Number
Dry Density (pcf)
Moisture (%)
Classification Symbol

MATERIAL DESCRIPTION
0 2
4 6
8 10
12 B o i @
sc
Topsoi l"Colluvium": Clayey SAND; dark brown, very moist, loose Cretaceous Tonalite (Kt): TONALITE; light grayish brown, moist, moderately hard to hard
Total Depth 4 Feet
No Groundwater
Will
SO LS
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340 of 876

APPENDIX C

LABORATORY PROCEDURES AND TEST

RESULTS
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APPENDIX C
Laboratory Procedures and Test Results
Our laboratory testing has provided quantitative and qualitative data involving the relevant engineering properties of the representative soils selected for testing. Representative samples were tested using the guidelines of the American Society for Testing and Materials (ASTM) procedures or California Test Methods (CTM).

Soil Classification: The soils observed during exploration were classified and logged in general accordance with the Standard Practice for Description and Identification of Soils (Visual -Manual Procedure) of ASTM D 2488.

Upon completion of laboratory testing, exploratory logs and sample descriptions may have been reconciled to reflect laboratory test results with regard to ASTM D 2487.

Maximum Density Tests: The maximum dry density and optimum moisture content of representative samples were determined using the guidelines of ASTM D1557. The test results are presented in the table below. r--- SAMPLE

LOCATION

MATERIAL

DESCRIPTION

MAXIMUM DRY

OPTIMUMVI MOISTURE
CONTENT (%)
DENSITY (pcf)
HA -1 @ 0-4 feet
Clayey SAND
123.5

12.0 Expansion Index: The expansion potential of representative samples was evaluated using the guidelines of ASTM D 4829. The test results are presented in the table below.

SAMPLE

LOCATION

MATERIAL

DESCRIPTION

EXPANSION INDEX

EXPANSION

POTENTIAL
HA -1 @ 0-4 feet
Clayey SAND
32 LOW
R -Value: The R -value of representative samples was determined using the guidelines of CTM 301. The test results are presented in the table below.

SAMPLE LOCATION

MATERIAL DESCRIPTION

R -VALUE
B-9 (Geocon, 2021)
Clayey SAND
12 Minimum Resistivity and pH Tests: Minimum resistivity and pH tests of select samples were performed using the guidelines of CTM 643. The test results are presented in the table below.

SAMPLE

LOCATION

MATERIAL

DESCRIPTION
L

MINIMUM

RESISTIVITY
(ohm -cm)
HA -1 @ 0-4 feet
Clayey SAND

8.9 2,020
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342 of 876

Soluble Sulfate: The soluble sulfate content of select samples was determined using the guidelines of CTM 417.

The test results are presented in the table below.

SAMPLE

LOCATION

MATERIAL '

SULFATE EXPOSURE

SULFATE CONTENT
(% by weight)

DESCRIPTION
HA -1 @ 0-4 feet
Clayey SAND

0.002
Negligible
Chloride Content: Chloride content of select samples was determined using the guidelines of CTM 422. The test results are presented in the table below.

SAMPLE LOCATION

MATERIAL DESCRIPTION
CHLORIDE CONTENT (ppm)
HA -1 @ 0-4 feet
Clayey SAND
0 08/11/2026
PH2 343 of 876

APPENDIX D

SEISMICITY
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PH2 344 of 876

USGS web services were down for some period of time and as a result this tool wasn't operational, resulting in timeout error.

USGS web services are now operational so this tool should work as expected.

Latitude, Longitude: 33.2207, -117.2555
Sunset at Melrose Heights
by Trumark Homes
0 Shell 9
0 Skye Apartments9
W Bobier Dr
W 8 Dr
ooa Dr
ui nogeaew
OSHPD
©The Church of
Jesus Christ of Latter...

W Bobier Dr
Chad Ct
-
Map data ©2024 Google
Date
Design Code Reference Document
Risk Category
Site Class
4/24/2024, 7:17:46 PM
ASCE7-16
I I
B - Rock
Type Value Description
Ss 0.92 MCER ground motion. (for 0.2 second period)
S1 0.34 MCER ground motion. (for 1.0s period)
SMs 0.828 Site -modified spectral acceleration value
SM1 0.272 Site -modified spectral acceleration value
SDS 0.552 Numeric seismic design value at 0.2 second SA SD1 0.181 Numeric seismic design value at 1.0 second SA Type Value Description
SDC D Seismic design category
Fa 0.9 Site amplification factor at 0.2 second
Fv 0.8 Site amplification factor at 1.0 second
PGA 0.397 MCEG peak ground acceleration
FPGA 0.9 Site amplification factor at PGA
PGAM 0.358 Site modified peak ground acceleration
TL 8 Long -period transition period in seconds
SsRT 0.92 Probabilistic risk -targeted ground motion. (0.2 second) SsUH 0.999 Factored uniform -hazard (2% probability of exceedance in 50 years) spectral acceleration SsD 1.5 Factored deterministic acceleration value. (0.2 second) S1RT 0.34 Probabilistic risk -targeted ground motion. (1.0 second) S1 UH 0.368 Factored uniform -hazard (2% probability of exceedance in 50 years) spectral acceleration.

S1 D 0.6 Factored deterministic acceleration value. (1.0 second) PGAd 0.5 Factored deterministic acceleration value. (Peak Ground Acceleration) PGAUH 0.397 Uniform -hazard (2% probability of exceedance in 50 years) Peak Ground Acceleration CRS 0.921 Mapped value of the risk coefficient at short periods 08/11/2026
PH2 345 of 876

Type Value Description
CR1 0.923 Mapped value of the risk coefficient at a period of 1 s Cv 0.9 Vertical coefficient
08/11/2026
PH2 346 of 876

U.S. Geological Survey - Earthquake Hazards Program
Unified Hazard Tool
Please do not use this tool to obtain ground motion parameter values for the design code reference documents covered by the U.S. Seismic Design Maps web tools (e.g., the International Building Code and the ASCE 7 or 41 Standard). The values returned by the two applications are not identical.

Please also see the new USGS Earthquake Hazard Toolbox for access to the most recent NSHMs for the conterminous U.S. and Hawaii.
^ Input
Edition
Dynamic: Conterminous U.S. 2014 (u...

Latitude
Decimal degrees

33.2207
Longitude
Decimal degrees, negative values for western longitudes -117.2555
Site Class
760 m/s (B/C boundary)
Spectral Period
Peak Ground Acceleration
Time Horizon
Return period in years
2475
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PH2 347 of 876

^ Hazard Curve
Please select "Edition"; "Location" & "Site Class" above to compute a hazard curve.

Compute Hazard Curve
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PH2 348 of 876

^ Deaggregation
Component
Total
▪ E_(-0°..-2.5)
▪ E = [-2.5 .. -2)
❑ E _ [-2 .. -1.5)
❑ E = [-1.5 .. -1)
❑ E _ [-1.. -0.5)
❑ E _ [-0.5 .. 0)
❑ E _ [0 .. 0.5)
❑ E=[0.5..1)
❑ E _ [1.. 1.5)
▪ E = [1.5 .. 2)
▪ E=[2..2.5)
▪ E = [2.5 .. +OO)
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PH2 349 of 876

Summary statistics for, Deaggregation: Total
Deaggregation targets Recovered targets
Return period: 2475 yrs
Exceedance rate: 0.0004040404 yr'
PGA ground motion: 0.40720454 g
Return period: 2794.277 yrs
Exceedance rate: 0.00035787432 yr'
Totals Mean (over all sources)
Binned: 100 0/0
Residual: 0 0/0
Trace: 0.11
m: 6.58
r: 17.18 km
Eo: 1.29 a
Mode (largest m -r bin) Mode (largest m -r -E0 bin)
m: 7.71
r: 25.99 km
Eo: 1.33 a
Contribution: 9.510/0
m: 7.72
r: 26.1 km
Eo: 1.33 a
Contribution: 6.93 0/0
Discretization Epsilon keys
r: min = 0.0, max=1000.0, A = 20.O km
m: min = 4.4, max =9.4,0=0.2
E: min =-3.0, max = 3.0, A= 0.5 a
E0: [-co .. -2.5)
El: [-2.5 .. -2.0)
E2: [-2.0 .. -1.5)
E3: [-1.5 .. -1.0)
E4: [-1.0 .. -0.5)
E5: [-0.5 .. 0.0)
E6: [0.0 .. 0.5)
£7: [0.5 ..1.0)
£8: [1.0 .. 1.5)
£9: [1.5 .. 2.0)
E10: [2.0 .. 2.5)
E11: [2.5 .. +oo]
08/11/2026
PH2 350 of 876

Deaggregation Contributors
Source Set y Source
UC33brAvg_FM31(opt)
PointSourceFinite: -117.256, 33.270
PointSourceFinite: -117.256, 33.270
PointSourceFinite: -117.256, 33.261
PointSourceFinite: -117.256, 33.261
PointSourceFinite: -117.256, 33.306
PointSourceFinite: -117.256, 33.306
PointSourceFinite: -117.256, 33.315
PointSourceFinite: -117.256, 33.315
PointSourceFinite: -117.256, 33.351
PointSourceFinite: -117.256, 33.351
U C33 b rAvg_FM 32 (opt)
PointSourceFinite: -117.256, 33.270
PointSourceFinite: -117.256, 33.270
PointSourceFinite: -117.256, 33.261
PointSourceFinite: -117.256, 33.261
PointSourceFinite: -117.256, 33.306
PointSourceFinite: -117.256, 33.306
PointSourceFinite: -117.256, 33.315
PointSourceFinite: -117.256, 33.315
PointSourceFinite: -117.256, 33.351
PointSourceFinite: -117.256, 33.351
UC33brAvg_FM31
Elsinore (Temecula) rev [5]
Newport -Inglewood (Offshore) [13]
Oceanside altl [0]
San Jacinto (Anza) rev [0]
Rose Canyon [19]
UC33brAvg_FM32
Elsinore (Temecula) rev [5]
Newport -Inglewood (Offshore) [13]
San Jacinto (Anza) rev [0]
Rose Canyon [19]
Oceanside alt2 [6]
Type r m Eo Ion lat az ok
Grid 29.39

7.09 5.85 0.83 117.255°W 33.270°N 0.00 3.68

7.09 5.85 0.83 117.255°W 33.270°N 0.00 3.68

6.58 5.78 0.79 117.255°W 33.261°N 0.00 3.41

6.58 5.78 0.79 117.255°W 33.261°N 0.00 3.41

9.44 6.03 L08 117.255°W 33.306°N 0.00 1.85

9.44 6.03 1.08 117.255°W 33.306°N 0.00 1.85

10.06 6.08 1.13 117.255°W 33.315°N 0.00 1.82

10.06 6.08 L13 117.255°W 33.315°N 0.00 1.82

12.83 6.20 1.39 117.255°W 33.351°N 0.00 1.37

12.83 6.20 1.39 117.255°W 33.351°N 0.00 1.37
Grid
System
System

29.28 7.09 5.85 0.83 117.255°W 33.270°N 0.00 3.67

7.09 5.85 0.83 117.255°W 33.270°N 0.00 3.67

6.58 5.78 0.79 117.255°W 33.261°N 0.00 3.40

6.58 5.78 0.79 117.255°W 33.261°N 0.00 3.40

9.44 6.03 1.08 117.255°W 33.306°N 0.00 1.84

9.44 6.03 1.08 117.255°W 33.306°N 0.00 1.84

10.06 6.08 1.13 117.255°W 33.315°N 0.00 1.82

10.06 6.08 1.13 117.255°W 33.315°N 0.00 1.82

12.83 6.20 1.39 117.255°W 33.351°N 0.00 1.37

12.83 6.20 1.39 117.255°W 33.351°N 0.00 1.37

21.33 26.63 7.56 1.53 117.008°W 33.341°N 59.76 5.84

17.72 7.34 1.18 117.429°W 33.156°N 246.02 5.80

23.11 7.27 1.43 117.596°W 33.057°N 240.28 2.13

65.20 8.11 2.23 116.854°W 33.702°N 34.70 1.76

18.03 6.60 L78 117.412°W 33.125°N 233.92 1.71

20.00 26.63 7.59 1.50 117.008°W 33.341°N 59.76 6.11

17.72 7.32 1.20 117.429°W 33.156°N 246.02 5.70

65.20 8.11 2.24 116.854°W 33.702°N 34.70 1.73

18.03 6.64 1.74 117.412°W 33.125°N 233.92 L58

22.84 7.63 1.12 117.598°W 33.061°N 240.90 1.36
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PH2 351 of 876

APPENDIX E

PAVEMENT DESIGN CALCULATIONS
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PH2 352 of 876

PAVING DESIGN
PROJECT: Vista
PROJECT NO.: 23185-10A
)11TAT1
CONSULTANT: CW
CALCULATION SHEET NO.: Auto Parking

SO I LS

CALTRANS METHOD FOR DESIGN OF FLEXIBLE PAVEMENT
Input "R" value or "CBR" of native soil 12
Type of Index Property - "R" value or "CBR" (C or R) R R Value R Value used for Caltrans Method 12
Input Traffic Index (TI) 5
Calculated Total Gravel Equivalent (GE) 1.408 feet
Calculated Total Gravel Equivalent (GE) 16.896 inches
Calculated Gravel Factor (Gf) for NC paving 2.53
Gravel Factor for Base Course (Gf) 1.1
Pavement sections provided below are considered equal; but, do not reflect reviewing agency minimums.

Gravel Equivalent
GE GE Delta
(feet) (inches) (inches)
INCHES
A/C Section Minimum
Thickness Base
(inches) (inches)
FEET
NC Section Minimum
Thickness Base
(feet) (feet)

0.63 7.60 9.29

3.0 8.4

0.25 0.70

0.74 8.87 8.02

3.5 7.2

0.29 0.60

0.84 10.14 6.76

4.0 6.0

0.33 0.50

1.06 12.67 4.22

5.0 3.6

0.42 0.30

1.27 15.21 1.69

6.0 1.8

0.50 0.15

1.48 17.74 -0.85

7.0 0.58

1.69 20.28 -3.38

8.0 0.67

1.90 22.81 -5.92

9.0 0.75

2.11 25.35 -8.45

10.0 0.83

2.32 27.88 -10.99
1'.0

0.92 2.53 30.42 -13.52

12.0 1.00
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353 of 876

PAVING DESIGN
PROJECT: Vista
PROJECT NO.: 23185-10A
)11TAT1
CONSULTANT: CW
CALCULATION SHEET NO.: Auto Drives

SO I LS

CALTRANS METHOD FOR DESIGN OF FLEXIBLE PAVEMENT
Input "R" value or "CBR" of native soil 12
Type of Index Property - "R" value or "CBR" (C or R) R R Value R Value used for Caltrans Method 12
Input Traffic Index (TI) 6
Calculated Total Gravel Equivalent (GE) 1.6896 feet
Calculated Total Gravel Equivalent (GE) 20.2752 inches
Calculated Gravel Factor (Gf) for NC paving 2.31
Gravel Factor for Base Course (Gf) 1.1
Pavement sections provided below are considered equal; but, do not reflect reviewing agency minimums.

Gravel Equivalent
GE GE Delta
(feet) (inches) (inches)
INCHES
A/C Section Minimum
Thickness Base
(inches) (inches)
FEET
NC Section Minimum
Thickness Base
(feet) (feet)

0.58 6.94 13.33

3.0 12.0

0.25 1.00

0.67 8.10 12.18

3.5 10.8

0.29 0.90

0.77 9.26 11.02

4.0 10.2

0.33 0.85

0.96 11.57 8.71

5.0 7.8

0.42 0.65

1.16 13.88 6.39

6.0 6.0

0.50 0.50

1.35 16.20 4.08

7.0 3.6

0.58 0.30

1.54 18.51 1.76

8.0 1.8

0.67 0.15

1.74 20.83 -0.55

9.0 0.75

1.93 23.14 -2.86

10.0 0.83

2.12 25.45 -5.18
1' .0

0.92 2.31 27.77 -7.49

12.0 1.00
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PH2
354 of 876

PAVING DESIGN
PROJECT: Vista
PROJECT NO.: 23185-10A
)11TAT1
CONSULTANT: CW
CALCULATION SHEET NO.: Truck Drives

SO I LS

CALTRANS METHOD FOR DESIGN OF FLEXIBLE PAVEMENT
Input "R" value or "CBR" of native soil 12
Type of Index Property - "R" value or "CBR" (C or R) R R Value R Value used for Caltrans Method 12
Input Traffic Index (TI) 7
Calculated Total Gravel Equivalent (GE) 1.9712 feet
Calculated Total Gravel Equivalent (GE) 23.6544 inches
Calculated Gravel Factor (Gf) for A/C paving 2.14
Gravel Factor for Base Course (Gf) 1.1
Pavement sections provided below are considered equal; but, do not reflect reviewing agency minimums.

Gravel Equivalent
GE GE Delta
(feet) (inches) (inches)
INCHES
A/C Section Minimum
Thickness Base
(inches) (inches)
FEET
NC Section Minimum
Thickness Base
(feet) (feet)

0.54 6.43 17.23

3.0 15.6

0.25 1.30

0.62 7.50 16.16

3.5 14.4

0.29 1.20

0.71 8.57 15.09

4.0 13.8

0.33 1.15

0.89 10.71 12.94

5.0 12.0

0.42 1.00

1.07 12.85 10.80

6.0 9.6

0.50 0.80

1.25 15.00 8.66

7.0 7.8

0.58 0.65

1.43 17.14 6.52

8.0 6.0

0.67 0.50

1.61 19.28 4.37

9.0 4.2

0.75 0.35

1.79 21.42 2.23

10.0 1.8

0.83 0.15

1.96 23.56 0.09
1' .0 0.0

0.92 0.00

2.14 25.71 -2.05

12.0 1.00
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APPENDIX F

GENERAL EARTHWORK AND GRADING

SPECIFICATIONS
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CW SOILS
General Earthwork and Grading Specifications
General
Intent: The following General Earthwork and Grading Specifications are intended to provide minimum requirements for grading operations and earthwork. These General Earthwork and Grading Specifications should be considered a part of the recommendations contained in the geotechnical report(s). If they are in conflict with the geotechnical report(s), the specific recommendations in the geotechnical report shall supersede these more general specifications. Observations made during earthwork operations by the Geotechnical Consultant may result in new or revised recommendations that may supersede these specifications and/or the recommendations in the geotechnical report(s).

The Geotechnical Consultant of Record: The Owner shall retain a qualified Consultant of Record (Geotechnical Consultant), prior to commencement of grading operations or construction. The Geotechnical Consultant shall be responsible for reviewing the approved geotechnical report(s) and accepting the adequacy of the preliminary geotechnical fmdings, conclusions, and recommendations prior to the commencement of the grading operations or construction.

Prior to commencement of grading operations or construction, the Owner shall coordinate with the Geotechnical Consultant, and Earthwork Contractor (Contractor) to schedule sufficient personnel for the appropriate level of observation, mapping, and compaction testing.

During earthwork and grading operations, the Geotechnical Consultant shall observe, map, and document the subsurface conditions to confirm assumptions made during the geotechnical design phase of the project. Should the actual conditions differ significantly from the interpretive assumptions made during the design phase, the Geotechnical Consultant shall recommend appropriate changes to accommodate the actual conditions, and notify the reviewing agency as needed.

The Geotechnical Consultant shall observe the moisture conditioning and processing of the excavations and fill operations. The Geotechnical Consultant should perform periodic compaction testing of engineered fills to verify that the required level of compaction is being accomplished as specified. cwsoils.com
08/11/2026
PH2 357 of 876

The Earthwork Contractor: The Earthwork Contractor (Contractor) shall be qualified, experienced, and knowledgeable in earthwork logistics, preparation and processing of excavations to receive compacted fill, moisture conditioning, processing of fill, and compacting fill. The Contractor shall be provided with the approved grading plans and geotechnical report(s) for his review and acceptance of responsibilities, prior to commencement of grading. The Contractor shall be solely responsible for performing the grading in accordance with the approved grading plans and geotechnical report(s). The Contractor shall inform the Owner and the Geotechnical Consultant of work schedule changes at least 24 hours in advance of such changes so that appropriate personnel will be available for observation and testing. Assumptions shall not be made by the Contractor with regard to whether the Geotechnical Consultant is aware of all grading operations.

It is the sole responsibility of the Contractor to provide adequate equipment and methods to accomplish the grading operations in accordance with the applicable grading codes and agency ordinances, these specifications, and the recommendations in the approved grading plan(s) and geotechnical report(s). Any unsatisfactory conditions, such as unsuitable soils, poor moisture conditioning, inadequate compaction, insufficient buttress keyway size, adverse weather conditions, etc., resulting in a quality of work less than required in the approved grading plans and geotechnical report(s), the Geotechnical Consultant shall reject the work and may recommend to the Owner that grading operations be stopped until operations are corrected, at the sole discretion of the Geotechnical Consultant.

Preparation of Areas for Compacted Fill
Clearing and Grubbing: Vegetation, such as brush, grass, roots, and other deleterious materials shall be sufficiently removed and properly disposed in a method acceptable to the Owner, Geotechnical Consultant, and governing agencies.

The Geotechnical Consultant shall evaluate the extent of these removals on a case by case basis. Soils to be placed as compacted fill shall not contain more than 1 percent organic materials (by volume). No compacted fill lift shall contain more than 10 percent organic matter.

If potentially hazardous materials are encountered, the Contractor shall stop work and exit the affected area, and a hazardous materials specialist shall immediately be consulted to evaluate the potentially hazardous materials, prior to continuing to work in that area.

It is our understanding that the State of California defines most refined petroleum products (gasoline, diesel fuel, motor oil, grease, coolant, etc.) as hazardous waste.

As such, indiscriminate dumping or spillage of these fluids may constitute a misdemeanor, punishable by fines and/or imprisonment, and shall be prohibited. cwsoils.com
08/11/2026
PH2 358 of 876

The contractor is responsible for all hazardous waste related to his operations. The Geotechnical Consultant does not have expertise in this area. If hazardous waste is a concern, then the Owner should contract the services of a qualified environmental assessor.

Processing: Exposed soils that have been observed to be satisfactory for support of compacted fill by the Geotechnical Consultant shall be scarified to a minimum depth of 6 inches. Exposed soils that are not satisfactory shall be removed or alternative recommendations may be provided by the Geotechnical Consultant.

Scarification shall continue until the exposed soils are free of oversize material and the working surface is reasonably uniform, flat, and free of uneven features that would inhibit uniform compaction. The soils should be moistened or air dried as necessary to achieve near optimum moisture content, prior to placement as engineered fill.

Overexcavation: The Typical Cut Lot Detail and Typical Cut/Fill Transition Lot Detail, included herein provide graphic illustrations that depicts typical overexcavation recommendations made in the approved grading plan(s) and/or geotechnical report(s).

Keyways and Benching: Where fills are to be placed on slopes steeper than 5:1 (horizontal to vertical), the ground shall be thoroughly benched as compacted fill is placed. Please see the three Typical Keyway and Benching Details with subtitles Cut Over Fill Slope, Fill Over Cut Slope, and Fill Slope for graphic illustrations.

The lowest bench or smallest keyway shall be a minimum of 15 feet wide (or %2 the proposed slope height) and at least 2 feet into competent soils as advised by the Geotechnical Consultant. Typical benching shall be excavated a minimum height of 4 feet into competent soils or as recommended by the Geotechnical Consultant.

Fill placed on slopes steeper than 5:1 should be thoroughly benched or otherwise excavated to provide a flat subgrade for the compacted fill. If unstable earth materials are encountered or anticipated the need for a buttress/stabilization fill may be required, see Typical Buttress/ Stabilization Detail herein.

Evaluation/Acceptance of Bottom Excavations: All areas to receive compacted fill (bottom excavations), including removal excavations, processed areas, keyways, and benching, shall be observed, mapped, general elevations recorded, and/or tested prior to being accepted by the Geotechnical Consultant as suitable to receive compacted fill. The Contractor shall obtain a written acceptance from the Geotechnical Consultant prior to placing compacted fill. A licensed surveyor shall provide the survey control for determining elevations of bottom excavations, processed areas, keyways, and benching. The Geotechnical Consultant is not responsible for erroneously located, fills, subdrain systems, or excavations. cwsoils.com
08/11/2026
PH2 359 of 876

Fill Materials
General: Soils to be used as compacted fill should be relatively free of organic matter and other deleterious substances as evaluated and accepted by the Geotechnical Consultant.

Oversize: Oversize material is rock that does not break down into smaller pieces and has a maximum diameter greater than 12 inches. Oversize rock shall not be included within compacted fill unless specific methods and guidelines acceptable to the Geotechnical Consultant are followed. For examples of methods and guidelines of oversize rock placement see the enclosed Typical Oversize Rock Disposal Detail. The inclusion of oversize materials in the compacted fill shall only be acceptable if the oversize material is completely surrounded by compacted fill or thoroughly jetted granular materials. No oversize material shall be placed within 10 vertical feet of fmish grade or within 2 feet of proposed utilities or underground improvements.

Import: Should imported soils be required, the proposed import materials shall meet the requirements of the Geotechnical Consultant. Well graded, very low expansion potential soils free of organic matter and other deleterious substances are usually the most desirable as import materials. It is generally in the Owners best interest that potential import soils are provided to the Geotechnical Consultant to determine their suitability for the intended purpose. Prior to starting import operations, at least 48 hours should be allotted for the appropriate laboratory testing to be performed.

Fill Placement and Compaction Procedures
Fill Layers: Fill materials shall be placed in areas prepared to receive engineered fill in nearly horizontal layers not exceeding 8 inches in loose thickness. Thicker layers may be accepted by the Geotechnical Consultant, provided field density testing indicates that the grading procedures can obtain adequate compaction. Each layer of fill shall be spread evenly and thoroughly mixed to obtain uniformity within the soils along with a consistent moisture throughout the fill.

Moisture Conditioning of Fill: Soils to be placed as compacted fill shall be watered, dried, blended, and/or mixed, as needed to obtain relatively uniform moisture contents that are at or slightly above optimum. The maximum density and optimum moisture content tests should be performed using the guidelines of the American Society of Testing and Materials (ASTM test method D1557-00).

Compaction of Fill: After each layer has been moisture conditioned, mixed, and evenly spread, it should be uniformly compacted to a minimum of 90 percent of the cwsoils.com
08/11/2026
PH2 360 of 876

maximum dry density as determined by ASTM test method D1557-00.

Compaction equipment shall be adequately sized and be either specifically designed for compaction of soils or be proven to consistently achieve the required level of compaction.

Compaction of Fill Slopes: In addition to normal compaction procedures specified above, additional effort to obtain compaction on slopes is needed. This may be accomplished by backrolling of slopes with sheepsfoot rollers as the fill is being placed, by overbuilding the fill slopes, or by other methods producing results that are satisfactory to the Geotechnical Consultant. Upon completion of grading, compaction of the fill and the slope face shall be a minimum of 90 percent of maximum density per ASTM test method D1557-00.

Compaction Testing of Fill: Field tests for moisture content and density of the compacted fill shall be periodically performed by the Geotechnical Consultant. The location and frequency of tests shall be at the Geotechnical Consultant's discretion.

Compaction test locations will not necessarily be random. The test locations may or may not be selected to verify minimum compaction requirements in areas that are typically prone to inadequate compaction, such as close to slope faces and near benching.

Frequency of Compaction Testing: Compaction tests shall be taken at minimum intervals of every 2 vertical feet and/or per 1,000 cubic yards of compacted materials placed. Additionally, as a guideline, at least one (1) test shall be taken on slope faces for each 5,000 square feet of slope face and/or for each 10 vertical feet of slope. The Contractor shall assure that fill placement is such that the testing schedule described herein can be accomplished by the Geotechnical Consultant.

The Contractor shall stop or slow down the earthwork operations to a safe level so that these minimum standards can be obtained.

Compaction Test Locations: The approximate elevation and horizontal coordinates of each test location shall be documented by the Geotechnical Consultant. The Contractor shall coordinate with the Surveyor to assure that sufficient grade stakes are established. This will provide the Geotechnical Consultant with the ability to determine the approximate test locations and elevations. The Geotechnical Consultant can not be responsible for staking erroneously located by the Surveyor or Contractor. A minimum of two grade stakes should be provided at a maximum horizontal distance of 100 feet and vertical difference of less than 5 feet.

Subdrain System Installation
Subdrain systems shall be installed in accordance with the approved geotechnical report(s), the approved grading plan(s), and the typical details provided herein, such as the Typical cwsoils.com
08/11/2026
PH2 361 of 876

Canyon Subdrain System Detail, etc. The Geotechnical Consultant may recommend additional subdrain systems and/or changes to the subdrain systems described herein, with regard to the extent, location, grade, or materials depending on conditions observed during grading or other factors. All subdrain systems shall be surveyed by a licensed land surveyor, with the exception of retaining wall subdrain systems, to verify line and grade after installation and prior to burial. Adequate time should be allowed by the Contractor to complete these surveys.

Excavation
All excavations and overexcavations shall be evaluated by the Geotechnical Consultant during grading operations. Any remedial removal depths indicated on the geotechnical maps are estimates only. The actual removal depths and extent shall be determined by the Geotechnical Consultant based on the field observations of exposed conditions during grading operations. Where fill over cut slopes are planned, the cut portion of the slope shall be excavated, evaluated, and accepted by the Geotechnical Consultant prior to placement of the fill portion of the proposed slope, unless specifically addressed by the Geotechnical Consultant. Typical details for cut over fill slopes and fill over cut slopes are provided herein. Foundation excavations should be made in accordance with the Foundation Clearances from Slopes Detail unless otherwise specified by the site specific recommendations by the Geotechnical Consultant.

Trench Backfill
1) The Contractor shall follow all OHSA and Cal/OSHA requirements for trench excavation safety.
2) Bedding and backfill of utility trenches shall be done in accordance with the applicable provisions in the Standard Specifications of Public Works Construction.

Bedding materials shall have a Sand Equivalency more than 30 (SE>30). The bedding shall be placed to 1 foot over the conduit and thoroughly jetting to provide densification. Backfill should be compacted to a minimum of 90 percent of maximum dry density, from 1 foot above the top of the conduit to the surface. 3) Jetting of the bedding materials around the conduits shall be observed by the Geotechnical Consultant.
4) The Geotechnical Consultant shall test trench backfill for the minimum compaction requirements recommended herein. At least one test should be conducted for every 300 linear feet of trench and for each 2 vertical feet of backfill. 5) For trench backfill the lift thicknesses shall not exceed those allowed in the Standard Specifications of Public Works Construction, unless the Contractor can demonstrate to the Geotechnical Consultant that the fill lift can be compacted to the minimum compaction requirements by the alternative equipment or method. cwsoils.com
08/11/2026
PH2 362 of 876

TYPICAL CUT LOT DETAIL
ULV Su .-, U.;l
...•• •""�

REMOV E UNSUITA BLE MATERIA LS

PROPOSED GRAD E
i COMPA CTED FILLS's

OVEREXCAVATE AND RECO MPACT
COMPETENT EARTHfMATERIAI
II
1:1 PRO JECTION TO COMPETEN T

EARTH MATERIA LS
1111
11111
NOTE; REMOVA L BOTTO MS SHOULD BE GRA DED WITH A
MINIMU M 2 % FALL TOWARDS STREET OR OTHER SUITABLE AREA (A S DETER MINED BY THE GEOTECHNICAL CONSU LTANT) TO

A VO ID POND ING BELOW THE BUILDING
NOTE: WHERE DESIG N CUT LO TS AR E EX CAVATED EN TIRELY INTO

COMPETENT EARTH MATERIALS , OVEREXCAVATION MAY STILL

BY N EED ED FO R HA RD -ROCK CO ND ITION S OR MA TERIALS WITH

VARIABLE EXPA NSION POTENTIA LS

ORI GINAL GRA DE
1:1 P ROJECTION TO COMPETENT

EARTH MATERIALS
5 FEET MIN BUT VARIES
cv',

SO I LS

TYPICAL C UT/ FILL TRANSITION LOT DETAIL
-o
2 V
3LV }U vU�

PROPO SED G RAD E
Il
-
i
...••• ••*".••••• •• •••
i

COMPA CTED FILL

TYPICA L BENCHING
NO TE: WHERE DESIGN CU T LO TS ARE EXCAV ATED ENTIRELY INTO

C OMPETENT MATERIA LS, OVEREXCAVATION MAY STILL BY

NEED ED FOR HARD -RO CK COND ITIONS OR MA TERIA LS WITH

VARIABLE EXPANSIO N PO TEN TIALS
III
1:1 PROJECTION TO

COMPETENT MATERI ALS
5 FEET MIN tUT V ARIES
*IV
SO I L_ S

TYPICAL KEYWAY & BENCHING DETAIL

FILL SLOPE

PR OPOSED GRA DE

C ONTA CT BETWEEN SUITA BLE AND

U NSU ITA BLE MATERIALS TO BE REMOVED
1:1 PROJECTION TO COMPL1 ENT EARTH

D IATERIA LS FROM PROPO SED TOE OF SLOPE
ULV }A.) �y�
1:1 TEMPORA RY CU T -

2. 0 FEET M IND

NATUR AL GR ADE

III - I
nir
VIII
C OMPAC`1'ED FILL
VARIES
(4 FEET TYPICAL)

5.0 FEET

K EYWA Y D IMENSIONS PER GEOTECHNICAL CONSULTANT /
G EOLOG IST (TYPICA LLY H/2 OR 15 FEET MIN.)

KEYWAY BOTTO M SHOULD DESCEND INTO SLOPE
NOTES:

H
(VARIES (8 FEET TYPICAL) -
NA TURAL SLO PES STEEPER THA N 5:1 (H:V ) MUST BE KEYED

AND BENCHED INTO COMPETENT EAR TH MATERIALS
SO IL

TYPICAL BUTTRESS / STABILIZATION DETAIL
1J
5 FE
zLV Su yy�
4 INCH SOLID PVC
OUTLET
2 MEET MIN
11111
III!
4 INCH S OLI D PVC

O UTLET

TYPICAL BENC HING

5.0 FEET
II
4 INCH

PERFORA T'E'D PVC

BA CK DRAIN

KEYWA Y DIMENSIONS PER GEOTECH NICA L CO NSULTAN T /
GEOLO GIST (TYPICA LLY H/2 OR 15 FEET MIN)

K EYWA Y BOTTOM

D ESCEND ING INTO SLOPE

P ROP OSED GRAD

OVEREXCAV ATION OF P AD, AS RECOMMENDE D
4 INCH
PERFOR A 1'E D P VC

BACKDRAI N

OMPACTE D FILL
n

BY GEOTECHNICAL C ONS ULTA NT
11111
F-15.0 FEET MIN
- 30 FEE
M AX

PROJECTED PLANE NO
STEEPER TH AN 1:1
A�RIC (MIRAFI 140N OR APPROVE D EQUIVALENT)
FIL1ERF

RFO RAIEDPVC PIPE WITH

PE RATIONS FACI NG DOWN
12 INCH MIN O VERLAP,
SECURED EVER Y 6FLE'
SCHEDULE 40 SOLID PVC OU TLET PIPE,\ I
SURROUNDED BY COMPACTED FILL. OUTLETS
100 FEET ON CEN TER OR IFS
5 CU BIC FEET / FOO T OF % -1 INCH OPEN

G RAD ED RO CK

TYPIC AL BENC HING
MIN
SOI LS

TYPICAL KEYWAY & BENCHING DETAIL

FILL OVER CUT SLOPE

PROP OSE D GR ADE

N ATURAL GR ADE

CONTACT BETWEEN SUITABLE A ND UNSUITABLE

EA RTH MATERIA LS TO BE REMOV ED

CUT SLOPE

PLEASE SEE N OTES -
III
1111
N414 � Jr COMPA CTE D FILL ti,
/.. 0
1T
rTITT=fTi
- VARIES
(4 FEET TYPICAL)
nfl _:s h'i ll�I _
II
III

15.0 FEET -I

KEYWA Y D IMENSIONS PER G EOTECHNICAL CO NSULTA NT /
GEOLOGIST (TYPICA LLY H/2 OR 15 FEET MIN.)

K EYWAY BOTTOM SHOULD D ESCEND INTO SLOPE
NOTES:

Iln
-VARIES (8 FEET TYPICAL)- ,
NATURAL SLOPES STEEPER THA N 5:1 (H:V) M UST BE KEYE D

A ND BEN CHED INTO COMPETENT EARTH MATERIALS

THE CU T SLO PE MU ST BE CO NSTRU CTED FIRST

TYPICAL CANYON S UBDRAIN SYSTEM DETAIL
ULV

PROPOSED GRA DE

NATURAL G RADE

U NSU ITABLE MA TERIALS TO BE REMOVED

TYPICA L BENCHING
TYPICALLY 10. 0 FEET

BU T VA RIES
6 IN CH SO LID PVC PIPE

C ONTACT BETWEEN SUIT ABLE AN D

UNSUIT ABLE MATERIAL TO BE REM OVE

COMPETENT MATERIA
•• Mill— I I J n n l
FILTER FABRIC (MIR AFI 140N OR APPR OVED EQ UIVALENT)
6 INCH C OLLE CT OR PIPE
(SCHE DULE 40 PERF OR ATED PVC PIPE

WITH PERF OR ATI ONS FACING
12 INCHES MIN . OVERL AP, SE CURED E V1�RY MIN
6 FEET _�Ss `=: .^-'1� 6 INC
9 CUBIC FEE _ I / F OOT OF % -1 3 IN CH

OPE N GRA DED ROCK

TYPICAL CANYON SUBDR AIN OUTLET

20.0 FEET MIN _
6 INCH SOLID PVC PIPE
FILTER FABRIC (MIRAFI 140N OR A PPROVED EQUIVALENT)

PR OPOSED GR ADE

5. 0 FEET M IN
-1X INC H

OPEN GRADED
ROCK
6 INCH PERFORATED SC HEDULE 40 PVC PIPE.

NOTES:
1- CONTINUOUS RUNS IN E XCESS OF 500 FEET
LONG WILL REQUIRE AN 8 I NCH DI AMETER PIPE
2 - FINAL 20 FEET OF PIPE AT OUTLET WILL BE
S OLID AND BAC KFILLE D WITH COMP AC I El)

FINE-GRAINED MATERIALS

INCH MD

FOUNDATION CLEA RANCES F ROM SLOPES DETAIL
UGUG/ l• I4VU
-o
2 FACE OF

STRU CTURE
AT LEAST THE SMA LLER OF H/2 AND
15 FEET
m rm-„TT - rm

AT LE AST THE SMALLER OF
H/3 AND 40 FEET
TOP OF SLOPE- \
,fr r 11111 11111
- 11111 11111 - IIIII

TOE OF SLOPE
(CBC, 2010)
-11111=IIIII -
FACE OF FOOTIN G -N.1/4 .,
1111-111-1111- rm A-TR
_
•
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H

a)
N
cW
Co
al

15.5•
S89'17'04"E 87.68'

ACC VALLEY
GUTTER
rn
l
M

41.8'

15.5'
N.

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0 11
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0 L=95.24, 50.00
D=5'43'55" T D=5'441-373"
L=105.04 , =1050.00
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2 493'
-!V12'
0 N

HOA ACCESS AND

LANDSCAPE EASEMENT
N
r 24'
0 P
TP-3.0 _
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1433 j'
TP-4
• 143.8
CJ
143.8
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0 N
TP-5
1418'

Y OF VISTA
• 61QhLIRATTON BASMI
LOT 22
h
N
16 R
0,
N
l 1.
20'

ACC VALLEY
GUTTER

62.7'
❑ , \
4 35.7
N86' 7.04"W 2$7.67'
II

ON BASIN
P— IJrx-1
l
a
N

KNOLL CF -L ST
TRACT .\JO. :45-J
WAX WING DR Geologic Units
LEGEND
Locations are Approximate
u
ADD
ADU
ADU
ADU
HOA ACCESS AND _ _

LAND EASEMENT
Kt — Cretaceous Tonalite
Symbols
>Q
TP-7
HA -1
— Exploratory Test Pit
N
LA
— Exploratory Hand Auger
5'
J
CW
Proposed Vista

GEOTECHNICAL MAP
23185-10
1" = 40`
SOILS
2024
PLATE 1
Uti/'I "I /LU1b 1-'111
�(1 OT t5/b

April 25, 2024 Project No. 23185-10
Mr. Michael Schweitzer, P.E.

SWS ENGINEERING, INC.
1635 Lake San Marcos Drive, Suite 200
San Marcos, CA 92078
Subject: Infiltration System Design Interpretive Report, Proposed Vista Project, South side of West Bobier Drive and East of Sports Park Way, Oceanside, San Diego County, California In accordance with your request, CW Soils is pleased to present this infiltration system interpretive report for the proposed Vista Project, located on the south side of West Bobier Drive and east of Sports Park Way, Oceanside, San Diego County, California. The purpose of our feasibility study was to determine the onsite infiltration rates and physical characteristics of the subsurface soils within the vicinity of the proposed infiltration systems. We have provided guidelines for the design of onsite infiltration systems. This interpretive report is intended to provide onsite infiltration rates for the existing soils.

PROPOSED DEVELOPMENT
Based on our understanding of the proposed project, will include three main buildings consisting of 14 units along with 3 ADU buildings consisting of 6 units, private streets, interior driveways, utilities, and on -site infiltration areas.

INFILTRATION TESTING

INFILTRATION TESTING
Aardvark Permeameter testing was utilized to conduct in -situ infiltration tests within the proposed basins on April 11, 2024, to evaluate the infiltration rate(s) in order to estimate the amount of storm water runoff that can infiltrate into the proposed systems. The testing utilizes the constant head method with extremely accurate (0.2 ml resolution) hydraulic conductivity testing under saturated conditions, for the determination of reliable in -situ infiltration rates. Automated readings are taken at 1 minute intervals until the rate becomes constant and saturated hydraulic conductivity for the particular soil has been reached. This is reflected by the flattening of the curve generated by sample test data as shown on the Water Consumption Rate graph (Plot of Water Consumption Rate 08/11/2026 " CW SOILS, 23251 Kent Court, p,QWrpeta, CA 92562.951-304-3935 . 373 of 876

vs. Time) in the Appendices herein. Steady Flow Rate is achieved when the Water Consumption Rate changes less than +/- 5% for 3 consecutive readings.

The Aardvark Permeameter was utilized in replacement of the Guelph Permeameter as recommended by Soil Moisture Equipment
Corporation, due to the higher reliability, accuracy, and ease of use.

The Aardvark Permeameter is the latest version of the Guelph Permeameter.

Infiltration testing was conducted in a 3 -inch diameter test hole, at depths of 3.5 to 4 feet deep. The approximate location of infiltration testing is indicated on the attached Infiltration Map, Plate 1.

Infiltration testing was located by property boundary measurement on the site plan and/or by using geographic features.

Relatively shallow Aardvark Permeameter testing (P-1 & P-2) was conducted using the guidelines of the product instruction manuals.

Stabilized infiltration test readings are summarized in the following table and more detailed test data recorded in the field can be found in Appendix A. The test results are anticipated to be representative of the soils found in the vicinity of the test locations.

INFILTRATION TEST SUMMARY
TEST
NUMBER

TEST HOLE

DIAMETER
(in)
HOLE
DEPTH
(in)

SOIL DESCRIPTION

INFILTRATION
RATE (in/hr)
P-1
3 48

0.19 Claey SAND
P-2
3 42

0.18 Claey SAND

FINDINGS
SOILS
A general description of the soils observed on site is provided below:

Cretaceous Tonalite (map symbol Kt): Cretaceous age plutonic rock consisting of tonalite was mapped throughout the site. The tonalite was observed to be light grayish brown, slightly moist to moist, and in a moderately hard to very hard state. Typically, the upper 1 to 3 feet of this unit is more weathered and not as hard.
08/11/2026 " CW SOILS, 23251 Kent Court, p,QWr eta, CA 92562.951-304-3935 ' 374 of 876

CONCLUSIONS AND RECOMMENDATIONS

GENERAL
The shallow in -situ soils have an average infiltration rate of 0.185 in/hr. in the aeras tested, with no additional factor of safety being applied.

PLAN REVIEW AND CONSTRUCTION SERVICES
This report has been prepared for the exclusive use of SWS and their authorized representative. It is unlikely to contain sufficient information for other parties or other uses. CW Soils should be provided the opportunity to review the final design plans and specifications prior to construction, in order to verify that the recommendations have been properly incorporated into the project plans and specifications. If CW Soils is not accorded the opportunity to review the project plans and specifications, we are not responsibility for misinterpretation of our recommendations.

We recommend that CW Soils be retained to provide soils engineering and engineering geologic services during the grading and foundation excavation phases of work, in order to allow for design changes in the event that the subsurface conditions differ from those anticipated prior to construction.

CW Soils should review any changes in the project and modify the conclusions and recommendations of this report in writing. This report along with the drawings contained within are intended for design input purposes only and are not intended to act as construction drawings or specifications. In the event that conditions during grading or construction operations appear to differ from those indicated in this report, our office should be notified immediately, as appropriate revisions may be required.

REPORT LIMITATIONS
Our services were performed using the degree of care and skill ordinarily exercised, under similar circumstances, by reputable soils engineers and geologists, practicing at the time and location this report was prepared. No warranty, expressed or implied, is made as to the conclusions and professional advice included in this report.

Soils vary in type, strength, and other engineering properties between points of observation and exploration.

Groundwater and moisture conditions can also vary due to natural processes or the works of man on this or adjacent properties. As a result, we do not and cannot have complete knowledge of the subsurface conditions beneath the proposed project. No practical study can completely eliminate uncertainty with regard to the anticipated geologic and soils engineering conditions in connection with a proposed project. The conclusions and recommendations within this report are based upon the findings at the points of observation and are subject to confirmation by CW Soils based on the conditions revealed during grading and construction operations. 08/11/2026 " CW SOILS, 23251 Kent Court, p,QWrpeta, CA 92562.951-304-3935 . 375 of 876

This report was prepared with the understanding that it is the responsibility of the owner, to ensure that the conclusions and recommendations contained herein are brought to the attention of the other project consultants and are incorporated into the plans and specifications. The owners' contractor should implement the recommendations in this report and notify the owner as well as our office if they consider any of the recommendations presented herein to be unsafe or unsuitable.

CW Soils appreciates the opportunity to otter our services on this project. If' we can be of further assistance, please do not hesitate to contact the undersigned at your convenience.

Respectfully submitted,
CW Soils
Chad E. Welke, PG, CEG, PE
Principal Geologist/Engineer
Distribution: (1) Addressee (email)
Attachments: Appendix A — Infiltration Test Results
Plate 1 — Infiltration Map (Rear of text)
08/11/2026
sO LS, 23251
PH2 376 of 876

APPENDIX A

INFILTRATION TEST RESULTS
CW SOILS, 23251 Kent Court, Murrieta, CA 92562 - 951-304-3935 08/11/2026
PH2 377 of 876

Aarclvarl< rermeamete s
Location: 23185
Site: P1
Time interval between readings: 1 minute
Steady Flow Rate achieved when Water
Consumption Rate changes less than
+/- 10 % for 3 consecutive readings
Notes:

Ksat Method:

Glover Solution
Steady Flow Rate:

Temp. Adj. FR:

Percolation Rate:

Ksat:

39.800 ml/min

39.880 ml/min

1.260 min/cm

0.19 Inches / hour
-41=

3.1 inches
70°F
48 inches

16.1 inches
Soil Texture -Structure Category:

Hole Diameter
Water Temperature
Hole Depth
Water Height in Hole
Water Table Depth
Longitude:

Latitude:

Degrees Minutes Seconds
0 0
0 0
0 0
East
North
08/11/2026
PH2
378 of 876

Water Consumption Rate
500
•
400
300
E
a
E
200
0 E
100
0 3:50 PM
2000
1500
1000
500
0 3:55 PM
4:00 PM
4:05 PM
4:10 PM
Total Water Consumed
4:15 PM
3:5C PM 3:55 PM
4:00 PM
4 05 PM
4:10 PM
4:15 PM
08/11/2026
PH2 379 of 876

Time
Reservoir Water
Level
Elapsed Time Interval Water Total Water
Interval Consumed Consumed
Water
Consumption
Rate
3:46:31 PM 7352.8 ml
3:47:31 PM 6884.8 ml 1 minute 468.0 ml 468.0 ml 468.000 ml/min 3:48:31 PM 6787.8 ml 1 minute 97.0 ml 565.0 ml 97.000 ml/min 3:49:32 PM 6719.4 ml 1 minute 68A ml 633.4 ml 67.279 ml/min 3:50:31 PM 6663.4 ml 59 seconds 56.0 ml 689.4 ml 56.949 ml/min 3:51:32 PM 6612.0 ml 1 minute 51.4 ml 740.8 ml 50.557 ml/min 3:52:32 PM 6564.6 ml 1 minute 47.4 ml 788.2 ml 47.400 ml/min 3:53:32 PM 6522.0 ml 1 minute 42.6 ml 830.8 ml 42.600 ml/min 3:54:32 PM 6479.4 ml 1 minute 42.6 ml 873.4 ml 42.600 ml/min 3:55:32 PM 6440.6 ml 1 minute 38.8 ml 912.2 ml 38.800 ml/min 3:56:32 PM 6402.6 ml 1 minute 38.0 ml 950.2 ml 38.000 ml/min 3:57:32 PM 6365.0 ml 1 minute 37.6 ml 987.8 ml 37.600 ml/min 3:58:32 PM 6326.0 ml 1 minute 39.0 ml 1026.8 ml 39.000 ml/min 3:59:33 PM 6287.8 ml 1 minute 38.2 ml 1065.0 ml 37.574 ml/min 4:00:33 PM 6249.4 ml 1 minute 38.4 ml 1103.4 ml 38.400 ml/min 4:01:33 PM 6212.6 ml 1 minute 36.8 ml 1140.2 ml 36.800 ml/min 4:02:33 PM 6178.2 ml 1 minute 34.4 ml 1174.6 ml 34.400 ml/min 4:03:33 PM 6142.2 ml 1 minute 36.0 ml 1210.6 ml 36.000 ml/min 4:04:33 PM 6106.6 ml 1 minute 35.6 ml 1246.2 ml 35.600 ml/min 4:05:33 PM 6073.4 ml 1 minute 33.2 ml 1279.4 ml 33.200 ml/min 4:06:34 PM 6042.2 ml 1 minute 31.2 ml 1310.6 ml 30.689 ml/min 4:07:33 PM 6009.6 ml 59 seconds 32.6 ml 1343.2 ml 33.153 ml/min 4:08:34 PM 5976.6 ml 1 minute 33.0 ml 1376.2 ml 32.459 ml/min 4:09:34 PM 5945.6 ml 1 minute 31.0 ml 1407.2 ml 31.000 ml/min 4:10:34 PM 5914.8 ml 1 minute 30.8 ml 1438.0 ml 30.800 ml/min 4:11:34 PM 5885.0 ml 1 minute 29.8 ml 1467.8 ml 29.800 ml/min 4:12:34 PM 5854.6 ml 1 minute 30.4 ml 1498.2 ml 30.400 ml/min 4:13:34 PM 5826.8 ml 1 minute 27.8 ml 1526.0 ml 27.800 ml/min 4:14:34 PM 5795.8 ml 1 minute 31.0 ml 1557.0 ml 31.000 ml/min 4:15:35 PM 5766.0 ml 1 minute 29.8 ml 1586.8 ml 29.311 ml/min 4:16:35 PM 5737.0 ml 1 minute 29.0 ml 1615.8 ml 29.000 ml/min 4:17:35 PM 5708.4 ml 1 minute 28.6 ml 1644.4 ml 28.600 ml/min 4:18:35 PM 5680.6 ml 1 minute 27.8 ml 1672.2 ml 27.800 ml/min Ignore
Reading
08/11/2026
PH2 380 of 876

Aarclvarl< rermeamete s
Location: 23185
Site: P2
Time interval between readings: 1 minute
Steady Flow Rate achieved when Water
Consumption Rate changes less than
+/- 10 % for 3 consecutive readings
Notes:

Ksat Method:

Glover Solution
Steady Flow Rate:

Temp. Adj. FR:

Percolation Rate:

Ksat:

38.000 ml/min

38.076 ml/min
L320 min/cm

0.18 Inches / hour
-41=

3.1 inches
70°F

42.1 inches

16.1 inches
Soil Texture -Structure Category:

Hole Diameter
Water Temperature
Hole Depth
Water Height in Hole
Water Table Depth
Longitude:

Latitude:

Degrees Minutes Seconds
0 0
0 0
0 0
East
North
08/11/2026
PH2
381 of 876

Water Consumption Rate
1200
1000
SOD
600
a
E
0 E
400
200
2500
200C
150C
1000
500
4:35 PM
4:40 PM
4:45 PM
4:5C PM
4:55 PM
5:D0 PM
4:35 PM
4:40 PM
4:45 PM
4:50 PM
4:55 PM
5:D0 PM
Total Water Consumed
08/11/2026
PH2 382 of 876

Time
Reservoir Water
Level

4.31:45 PM 8338.0 ml
4:32:45 PM 7189.8 ml
4:33:45 PM 7016.4 ml
4:34:45 PM 6940.8 ml
4:35:45 PM 6885.6 ml
4:36:45 PM 6840.4 ml
4:37:46 PM 6801.0 ml
4:38:46 PM 6760.8 ml
4:39:46 PM 6724.6 ml
4:40:46 PM 6687.0 ml
4:41:46 PM 6647.6 ml
4:42:46 PM 6611.6 ml
4:43:46 PM 6572.8 ml
4:44:46 PM 6533.2 ml
4:45:47 PM 6497.6 ml
4:46:47 PM 6459.4 ml
4:47:47 PM 6424.0 ml
4:48:47 PM 6390.8 ml
4:49:47 PM 6357.0 ml
4:50:47 PM 6323.0 ml
4:51:48 PM 6287.2 ml
4:52:48 PM 6252.8 ml
4:53:48 PM 6220.4 ml
4:54:48 PM 6188.2 ml
4:55:48 PM 6155.8 ml
4:56:48 PM 6121.0 ml
4:57:48 PM 6089.6 ml
4:58:48 PM 6057.4 ml
4:59:48 PM 6024.8 ml
5:00:48 PM 5994.0 ml
5:01:48 PM 5962.0 ml
Elapsed Time Interval Water Total Water
Interval Consumed Consumed
minute
minute
minute
minute
minute
minute
minute
minute
minute
minute
minute
minute
minute
minute
minute
minute
minute
minute
minute
minute
minute
minute
minute
minute
minute
minute
minute
minute
minute
minute
1148.2 ml
173.4 ml

75.6 ml

55.2 ml

45.2 ml

39.4 ml

40.2 ml

36.2 ml

37.6 ml

39.4 ml

36.0 ml

38.8 ml

39.6 ml

35.6 ml

38.2 ml

35.4 ml

33.2 ml

33.8 ml

34.0 ml

35.8 ml

34.4 ml

32.4 ml

32.2 ml

32.4 ml

34.8 ml

31.4 ml

32.2 ml

32.6 ml

30.8 ml

32.0 ml
1148.2 ml
1321.6 ml
1397.2 ml
1452.4 ml
1497.6 ml
1537.0 ml
1577.2 ml
1613.4 ml
1651.0 ml
1690.4 ml
1726.4 ml
1765.2 ml
1804.8 ml
1840.4 ml
1878.6 ml
1914.0 ml
1947.2 ml
1981.0 ml
2015.0 ml
2050.8 ml
2085.2 ml
2117.6 ml
2149.8 ml
2182.2 ml
2217.0 ml
2248.4 ml
2280.6 ml
2313.2 ml
2344.0 ml
2376.0 ml
Water
Consumption
Rate
1148.200 ml/min
173.400 ml/min

75.600 ml/min

55.200 ml/min

45.200 ml/min

38.754 ml/min

40.200 ml/min

36.200 ml/min

37.600 ml/min

39.400 ml/min

36.000 ml/min

38.800 ml/min

39.600 ml/min

35.016 ml/min

38.200 ml/min

35.400 ml/min

33.200 ml/min

33.800 ml/min

34.000 ml/min

35.213 ml/min

34.400 ml/min

32.400 ml/min

32.200 ml/min

32.400 ml/min

34.800 ml/min

31.400 ml/min

32.200 ml/min

32.600 ml/min

30.800 ml/min

32.000 ml/min
Ignore
Reading
08/11/2026
PH2 383 of 876

C)
0 Y OF VISTA
cwISOILS
V
O
Lor 22
I I
iJ
0 L=95.24, 50.00
D=5'43'55" T D=5'441-373"
L=105.04 , =1050.00
12'
24' —1/
7 c; rl lV L o
N85''
Is!
143.8'
7'04"W 27.67' 1
KNOLL CR S r
7RACr .VD, 4TJ
WAX WING DR Geologic Units
Kt
Symbols
P-2
N

HOA ACCESS AND

LANDSCAPE EASEMENT
CD
CD
14,18'
14,38'
12 1418 Kt
1418'
ON BASIN •
P4 _
LEGEND
Locations are Approximate
— Cretaceous Tonalite
— Infiltration Test

ACC VALLEY
g1T1ER
1 5'
5'
Proposed Vista

INFILTRATION MAP
23185-10A
1"=40`
2024
PLATE 1
lib/"I "I/LULb x'112
364OT i(b

March 25, 2025 Project No. 23185-10
Mr. Michael Schweitzer, P.E.

SWS ENGINEERING, INC.
1635 Lake San Marcos Drive, Suite 200
San Marcos, CA 92078
Subject:

References:

Biofiltration Basin Plan Review Letter, Proposed Bobier Drive 15 Lot Project, 552 West Bobier Drive, City of Vista, San Diego County, California SWS Engineering, Inc., 2025. Grading, Drainage and Utility Plan, Sheet 3 of 20, March 13, 2025
CW Soils, Inc., 2024, Preliminary Geotechnical Interpretive Report, Vista Project, South side of West Bobier Drive and East of Sports Park Way, Oceanside, San Diego County, California, dated April 25, 2024.

Pursuant to your request, CW Soils performed a plan review of the biofiltration basins with regard to the references above. The proposed Bobier Drive 15 Lot Project is located at 552 West Bobier Drive in the City of Vista, San Diego County, California. It is our opinion that the proposed biofiltration basins with 2:1 (horizontal:vertical) side slopes up to 21 inches in depth are acceptable and have been planned in general conformance with the referenced geotechnical report.

All structure foundation and biofiltration basin excavations near structures should be observed by project geologist/engineer of CW Soils, Inc. prior to infilling.

CW Soils appreciates the opportunity to offer our services on this project. If we can be of further assistance, please do not hesitate to contact the undersigned at your convenience.

Respectfully submitted,
CW Soils
ad E. Welke. PG. CEG, PE
Principal Geologist/Engineer
Distribution: (1) Addressee (email)
232'31 Kent Court, Murrieta, CA 92562 951 )(.14-39-3"-_, 08/11/2026
PH2
385 of 876

Appendix E
Drainage Study
08/11/2026
PH2 386 of 876

PRELIMINARY DRAINAGE STUDY
FOR
Waxwing Drive Subdivision
552 W Bobier Drive
Vista, CA 92083
APN: 161-030-07
Prepared for:

SWS Engineering, Inc.
1635 Lake San Marcos Drive, Suite 200
San Marcos, CA 92078
Engineer:

SWS
ENGINEERING, INC.
engineering. made. passible.

SWS Engineering, Inc.
1635 Lake San Marcos Drive, Suite 200
San Marcos, California 92078
760-744-0011
PN: 23-299

I HEREBY DECLARE THAT I AM THE ENGINEER OF WORK FOR THIS PROJECT, THAT I

HAVE EXERCISED RESPONSIBLE CHARGE OVER THE DESIGN OF THE PROJECT AS DEFINED IN SECTION 6703 OF THE BUSINESS AND PROFESSIONAL CODE, AND THAT THE DESIGN IN CONSISTENT WITH CURRENT STANDARDS.

I UNDERSTAND THAT THE CHECK OF PROJECT DRAWINGS AND SPECIFICATIONS BY

THE COUNTY OF SAN DIEGO IS CONFINED TO A REVIEW ONLY AND DOES NOT

RELIEVE ME, AS ENGINEER OF WORK, OF MY RESPONSIBILITIES FOR THE PROJECT DESIGN.

Prepared by: Date:

Michael D. Schweitzer RCE# 59658 Exp. 12-31-25
Date Comments
4/23/2024 1st
11/04/2024 2nd
1/08/2025 3rd
3/17/2025 4th
4/17/2025 5th
08/11/2026
PH2 387 of 876

TABLE OF CONTENTS

1.0 PROJECT DESCRIPTION 1

2.0 PURPOSE 1

3.0 METHODOLOGY 1

4.0 HYDROLOGY 2

4.1 Pre -Development Condition 2

4.2 Post -Development Conditions 3

4.3 FEMA NFIP 4

5.0 CONCLUSION 4

APPENDICES
Appendix A — Reference Charts
Table 3-1 — Runoff Coefficients for Urban Areas
Figure 3-1 — Intensity- Duration Design Chart
Soil Hydrologic Groups Map
100 Year Rainfall Event — 6 Hours (P6 Rainfall Isopluvials) 100 Year Rainfall Event — 24 Hours (P24 Rainfall Isopluvials Appendix B — Pre -Development Hydrology Calculations
Appendix C — Post -Development Hydrology Calculations
Appendix D — Attenuation/Hydraulic Analysis

EXHIBITS
Exhibit "A" — Pre -Development Hydrology Map
Exhibit "B" — Post -Development Hydrology Map
Associated General Contractors - i -
08/11/2026
PH2
County of San Diego
388 of 876

1.0 PROJECT DESCRIPTION
The proposed project site consists of 15 townhomes (two-story structure) with associated driveway, private street, utilities, and other associated improvements and treatment basins. The project site is one parcel with a total area of 1.67 ac that is located south of West Bobier Drive and at the north end of the current extent of Waxwing Drive in the City of Vista, California. The site is located on R -1-B (7.5) Single -Family Residential zone. It is an exciting improvement to be demolished. The proposed land use for this project is MDR (Medium Density Residential).

The Church of 4
Jesus Christ of Latter
,--- s --.r

2.0 PURPOSE
The purpose of this study is to determine the peak runoff rates and velocities for the pre - development and post -development conditions. Comparisons will be made between each condition to determine the extent of the effects of the proposed improvements on site drainage and adjacent properties. The adequacy of proposed conveyance facilities (riser structures for 100-yr flow and available freeboard of equal or greater than 6") will also be determined. Refer to section 5 (conclusion) for more detail and attenuation analysis in appendix D.

Waxwing
08/11/2026
-1-
PH2
City of Vista
389 of 876

3.0 METHODOLOGY
The Rational Method as outlined in the San Diego County Hydrology Manual, dated June 2003, was used to determine the runoff flow rate. The 100 -year frequency storm event was analyzed to determine peak runoff rates discharging the site for both the existing and post -development condition.

Soil type was determined to be type D from the Soil Hydrologic Groups map, NRCS Web Soil Survey (see Appendix A). Per the Web Soil Survey, the site has Bonsall sandy loam and Diablo clay, with slopes ranging from 2-15 percent. The runoff coefficient "C" was determined by using the closes matching land use category in Table 3-1 (Appendix A). The exhibits have been prepared for the pre -development and post -development conditions and are attached as Exhibits "A" and "B".

Runoff coefficients, "C" are summarized below.
• Pre -Development
o Undisturbed Natural Terrain C = 0.35 (soil type D)
• Post -Development
o From the table 3-1, the nearest weighted C coefficient was selected per %impervious area for each basin and sub -basin. Due to site limited available space, 100 sf future impervious contingency has been accounted for each lot.

Basin
Area
Impervious
Area (ac)
% IMP
HSG
Weighted C*
1 0.14

0.03 21.1
D

0.47 2

0.09 0.019

20.2 D

0.46 3

0.11 0.065

57.1 D

0.66 4i

0.038

0.00 0.00
D

0.35 4.2

0.022

0.00 0.00
D

0.35 4.3

0.028

0.00 0.00
D

0.35 5

0.26 0.22

84.3 D

0.81 6

0.17 0.059

35.6 D

0.55 7

0.78 0.54

70.0 D

0.73 8

0.03 0.00

0.00 D

0.35 * weighted C factor [(0.9 x impervious A) + (0.35 pervious A)]/Total Area

4.0 HYDROLOGY

4.1 Pre -Development Conditions
The project is situated on one parcel of total area 1.67 ac undeveloped land. The site had an existing structure that has been demolished around 2008-2009 with no new development. The site slopes range from 2-25%. Runoff from Basin 1 of the project site will surface flow from the undisturbed natural terrain north onto West Bobier Drive, where it enters the existing storm drain system located on the west of the high point on Bobier that drains to Guajome Lake and ultimately into San Luis Rey River. Basin 2 also drains into W Bobier Drive where it also enters into existing storm drain systems located on Moa Dr (east of Marabou Ln) and ultimately Waxwing
08/11/2026
-2-
PH2
City of Vista
390 of 876

discharges into Buena Vista Creek. Runoff from basins (3-5) sheet flow along natural terrain in the southeasterly direction (not concentrated) towards the existing residential development on Waxwing Drive and Mynah Place which then discharge into existing storm drain systems located on Moa Dr (east of Marabou Ln) and ultimately into Buena Vista Creek. (See attached exhibit for the confluence point).

Runoff from Basin 6 surface flows along the natural terrain that discharges offsite (adjacent property) in the southwesterly direction into existing concrete lined channel along the southern portion of the adjacent property then into public storm drain system and ultimately into Loam Alta Creek and finally into Pacific Ocean.

Majority of the site runoffs discharge into Loma Alta Creek and smaller area into Buena Vista Creek and ultimately into the Pacific Ocean. The small area draining toward Guajome Lake will be routed toward Buena Vista Creek in post condition.

The development of the site will not have any negative impact to the adjacent properties on the east, west and south as the development of the site will reduce the site runoff below the existing condition by constructing multiple basins to detain any excess water onsite. Also, much of the existing runoff to the east toward adjacent properties will be routed to the southwest in post condition. Rip rap will be added at the discharge point of each basin and POC points to reduce the runoff velocity of the discharge. The discharge points of the site will also be reduced.

There is no offsite run on in the existing condition. The improvement of the adjacent property on the west won't have any negative impact to our site as there is slope along site the project site drains away from out site and therefore there won't be any offsite draining to our project stie.

A pre -development hydrology map delineating basin areas, flow paths, and concentration points has been prepared and is attached to this report as Exhibit "A". Pre -development hydrology calculations can be found in Appendix "B)

4.2 Post -Development Conditions
The proposed site is undeveloped land that consists of 15 townhomes (two-story structure) with associated driveway, private street, utilities, and other associated improvements and treatment basins. The project site is one parcel with a total area of 1.67 ac that is located south of West Bobier Drive, and on the north end of the existing Waxwing Drive within the City of Vista, California.

The proposed site drainage from Basins 1 and 3 will surface flow via proposed site roofs, hardscape, and curb -gutter into a proposed treatment basins located in the north and northeast portion of the site prior to discharging into W Bobier Drive east of high point. Basin 2 that has small improvement will also surface flow in northerly direction into W Bobier Drive east of high point. Basins (4.1, 4.2, 4.3) which are landscape area will sheet flow offsite in the easterly direction as it does in the existing condition with very minor runoffs less/equal than 0.1 cfs. All the runoff from basins (1-4) ultimately discharge into existing storm drain systems located on Moa Dr (east of Marabou Ln) similar to the existing condition prior to discharging in Buena Vista Creek.

Basin 5 will sheet flow in the easterly direction into proposed treatment basin and then routed offsite via proposed storm drain system into southwest corner of the site. Basins 6 and 7 will discharge via curb gutter and catch basins into proposed treatment basins located on the west Waxwing
08/11/2026
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PH2
City of Vista
391 of 876

north and south side of the project site prior to discharging toward southwest offsite corner of the site via proposed storm drain systems. All the discharge runoff from basins (5-8) will discharge into existing lined channel along southern portion of the adjacent property on the west via concrete ditch that is built along eastside of the adjacent property (after the adjacent property development is completed). Basin 8 is a small landscape area that will sheet flow offsite on the westerly direction.

Majority of the site 1.24 ac (basins 5-8) runoffs will discharge into Loma Alta Creek and smaller area on the east portion of the site 0.43 ac (basins 1-4) into Buena Vista Creek via sheet flow and existing public storm drain systems and ultimately discharge into the Pacific Ocean.

The discharging runoff from basins 1-3 into W Babier Drive, will confluence with the runoff from basins (4.1, 4.2, 4.3) at Mynah PI and Marabou Ln which ultimately discharge in an existing storm drain systems located on Moa Dr (east of Marabou Ln).

The proposed project site will have an increase in flow compared to the existing condition due to the coefficient C, diversion and time of concentration. The excess Q will be detained by multiple proposed biofiltration basins to reduce the Q below the existing condition at the two POCs, one from basins (1-4) at the confluence point of Mynah PI and Marabou Ln and the second at the southwest corner of the site from basins (5-8).

There is no offsite run-on in the post -condition. The improvement of the adjacent property on the west won't have any negative impact to our site as there is slope along site the project site drains away from our site and therefore there won't be any offsite draining to our project site.

The development of our project site won't have any negative impact to the adjacent property since the excess runoff compared to existing condition will be detained onsite. The attenuated runoff will discharge into existing lined channel along the southern portion of the adjacent property via concrete ditch that is built along eastside of the adjacent property (after the property development is completed).

A post -development hydrology map delineating basin area, flow paths, concentration points, and proposed drainage facilities has been prepared and is attached to this report as Exhibit "B".

Post -development hydrology calculations can be found in Appendix C.

4.3 FEMA NFIP
Per FEMA-NFIP Map (Panel 0757, Map Number 06073C -0757G), the project is located within Zone X (0.2% annual chance flood, 1% annual chance flood with average depth of less than 1 foot or with drainage areas less than 1 square mile, and areas protected by levees from 1% annual chance flood).

5.0 CONCLUSION
The proposed project will change the flow patterns from that of the pre -developed site, while maintaining the discharge points from the site. Development of the project site will increase the runoff compared to the pre -developed condition with the addition of imperviousness. Table 1 provides a summary of the pre -development areas and flows. Table 2 provides a summary of the post -development areas and flows before and after attenuation analysis. Table 3 provides the total Q comparison between the pre and post -development conditions.

Waxwing
08/11/2026
-4-
PH2
City of Vista
392 of 876

Table 1 — Pre -Development Areas and Flows
Basins
Node
#
Area Pre
(ac)
Pre Q100
(cfs)
Basin -100
100*
102

0.034

0.10 POC-1
200**
202

0.056

0.16 300**
303

0.13 0.33
400**
402

0.19 0.49
500**
502

0.27 0.67
Total
-
-

1.65 POC-2
600***
603

0.99 2.20
Total
-
-

2.20 Basin 100 + POC-1 + POC-2
-
-

1.67 3.95
* Basin 100 drains into San Luis Rey River which will be routed to Buena Vista Creek in post condition (The Q not included at POC-1)
** POC-1: Q from basins (200-500) conferencing at Mynah PI and Marabou Ln =

0.16 + 0.33 + 0.49 + 0.67 = 1.65 cfs
*** POC-2: Q from basin 600 = 2.2 cfs
Table 2 — Post -Development Areas and Flows
Basins
Node
#
Area Post
(ac)
Post Q100
(cfs)
Attenuated Q
Before
Confluence (cfs)
Attenuated Q
@ POCs
(cfs)
POC-1
100
104

0.14 0.54

0.31 200
202

0.09 0.35

0.35 300
304

0.11 0.57

0.31 400.1
402

0.038

0.11 0.11
400.2
404

0.022

0.06 0.06
400.3
406

0.028

0.08 0.08
Total
-
-

1.71 1.22

1.22*
POC-2
500
503

0.26 1.79

1.01 600
602

0.17 0.73

0.38 700
703

0.78 4.88

0.90 800
802

0.03 0.09

0.09 Total
-
-

6.22 -

2.2**
POC-1 + POC-2
-
-

1.67 7.93

3.42<3.95 (ex)
* POC-1: Attenuated Q from basins (100-400) confluence at Mynah PI and Marabou Ln = 0.31 + 0.35 + 0.31 + 0.11 + 0.06 + 0.08= 1.22 cfs (post) < 1.65 cfs (Ex) **
POC-2: Attenuated Q from basin 500-800 = 2.2 cfs (post) =< 2.2 cfs (Ex), See mitigated drainage analysis for confluence point at nodes 802-704 Waxwing
08/11/2026
-5-
PH2
City of Vista
393 of 876

Table 3 — Increase in Q Between Pre and Post -Condition Condition
Area
(ac)
Total Q100
(cfs)
Pre -Development

1.67 3.95
Post Development

1.67 7.93
Increased Q ± (cfs)
-
+3.98
Attenuated Q
-

3.42 Results
-

3.42<3.95*
*Construction of onsite five biofiltration basins will reduce the site overall post Q below pre Q for 100-yr, reduction at the POC points (1 and 2) as well as satisfying the WQ and HMP requirements. There will be riser structure constructed on each basin to convey the 100-yr storm runoff offsite via proposed SD outlet in emergencies and failure. The provided freeboard in each basin is equal or greater than 6 -inch. Multiple Tree -Wells will be proposed to treat the site frontage improvement area as well as the frontage half street in exchange to the basin 2 that won't be treated. Tree -Well will also help further reduction on discharge runoff flow into W Bobier Drive.

The development of the site will not have any negative impact to the adjacent properties on the east, west and south as the development of the site will reduce the site runoff below the existing condition by constructing multiple basins to detain any excess water onsite. Rip rap will be added at the discharge point of each basin to reduce the velocity of runoffs as well as the discharge point into offsite.

Waxwing
08/11/2026
-6-
PH2
City of Vista
394 of 876

REFERENCES
CivilDesign Corporation. San Diego County Rational Method. (Software Version 7.7) County of San Diego Department of Public Works Flood Control Section. San Diego County Hydrology Manual. (2003)
County of San Diego Department of Public Works Flood Control Section. San Diego County Drainage Design Manual. (2005)
Waxwing
08/11/2026
5 PH2
City of Vista
395 of 876

APPENDIX A

REFERENCE CHARTS
08/11/2026
PH2 396 of 876

9Z0Z/ I 1. /80
San Diego County Hydrology Ma nual
Date: JLme 2003
Section:

Page:
3 6 of 26
Table 3-1

RUN OFF COEFFICIE NTS FOR URBA N AREAS
Land Use
Ru noff Coefficie nt "C"
NRCS Elements
Undisturbed Natural Terrain (N atural)
Low Den sity Residential (LD R)
Low Density R esidential (LDR)
Low D ensity Residential (LDR)
Medium Den sity Residential (MDR)
Mediu m Den sity Residen tial (MDR )
Medium Den sity Residential (MD R)
Mediu m Density R esidential (MDR)
High Den sity Residential (HDR)
High Density Residential (HDR )
Commercial/Industrial (N. Com)
Commercial/In dustrial (G. Com)
Co mmercial/Industrial (O. P. Com)
Commercial/Industrial (Limited I. )
Commercial/Industrial (General I. )
County Eleme nts
Permanent Open Space
Residential, 1.0 DU/A or less
Residen tial, 2.0 DU/A or less
Residential, 2.9 DU/A or less
Residential, 4. 3 DU/A or less
Residential, 7. 3 DU/A or less
Residential, 10.9 DU/A or less
Residential, 14.5 DU/A or less
Residen tial, 24.0 DU/A or less
Residential, 43. 0 DU/A or less
N eighborhood Commercial
General Com mercial
Office Profession al/Commercial
Limited Industrial
Gen eral Indu strial
Soil Tvoe
% IMPER. A
0* 0 .20
10 0.27
20 0.34
25 0 .38
30 0 .41
40 0 .48
45 0.52
50 0.55
65 0 .66
80 0 .76
80 0 .76
85 0 .80
90 0 .83
90 0 .83
95 0 .87
B

0.25 0.32

0.38 0 .41
0 .45
0 .51

0.54 0 .58
0 .67
0 .77
0 .77
0 .80
0 .84
0 .84
0 .87
C

0.30 0 .36

0.42 0.45

0.48 0.54
0 .57

0.60 0.69

0.78 0.78

0.81 0.84

0.84 0.87
D
0 .35

0.41 0.46
0 .49

0.52 0.57
0 .60

0.63 0.71

0.79 0.79

0.82 0.85

0.85 0.87
*The v alu es associated with 0% impervious may be used for direct calcu lation of the runoff coefficien t as described in Section 3 .1 .2 (representing the per vious ru noff coefficient, Cp, for the soil type), or for areas that will remain undisturbed in perpetu ity. Ju stification mu st be given that the area will remai n natural forever (e.g ., the area is located in Clevelan d N ation al Forest).

DU/A = dwelling un its per acre
NRCS = Nation al R esou rces Conservation Service
3-6

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a)
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10.0 9.0

Dire ctions for Applic ati on:

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i
(1) precipitation
for the selected frequency . These maps are included in the

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FIGURE
3- 1

9Z0Z/ I 1. /80
33° 13'16'N
✓
2 N P.-
.9
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CO
O
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33° 13'13" N
3 476130
476140
476150
476160
Mon Nab oin8$ 610a-u b1oo ocg,209.
1 476133
476140
476150
476160
Hydrologic Soil Group —San Diego County Area, California 476170
I �
476170
Map Scale: 1:681 if printed on A landscape (11" x 8. 5") sheet. 476180
476180
476190
4/ h
476210
476220
476230

I I I I I
476190
O
10 20
40 O 33 60
Map pro jectlon: Web M ercator Co rne r coordinates: WGS84 Edge tics: UTM Zo ne 11N WCS 84 Meters
60 Feet
120 180
476200
476210
476220
475230
476240
476240
476250
476250
476260
476260
117° 16 16' W
4ro2/0
33 ° 13'16"N
_
_�
0 I 33 ° 13' 13" N
4/t2/0
3 10
10 USDA Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
4/1/2024

Hydrologic Soil Group —San Diego County Area, California 9Z0Z/ I. 1. /80
918 40 0017

MAP LEGEND MAP INFOR MATION
Area of Interest (AOI)
I-7 Area of Interest (AOI)
Soils
Soil Rating Polygons
O A
F-7 A/D
O B
B/D
O C
O C/D
Not ra te d or no t available
Soil Rating Lines
r.o A
,. ,X A/D
▪ B/D
- C
ryr C/D
,y D
r Not rated or not available
So il Rating Po ints
© A
▪ A/D
D B
D B/D
© C
C/D
D D
• Not rated or not available
Water Features
Streams and Canals
Transp ortation
Rails
Int erstate Highways
US Routes
Major Roads
Local Roads
Background
Aerial Photography
The soil surveys that comprise your AOI were mapped at
1:24,000.

Warning: S oil Map may not be valid at this s cal e.

Enlargement of maps beyond the scale of mapping can cause misunderstanding of the d etail of mapping and ac cura cy of soil line placem ent. The maps do not sh ow the small areas of contrasting soils that could have been shown at a more det ailed scale.

Pleas e rely on the bar scale on each map sheet for map measurements .

Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:

Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required.

This product is generated from the USDA-NRCS certified data as of the version date(s) listed below.

Soil Survey Area: San Diego County Area, California
Survey Area Data: Version 19, Aug 30, 2023
Soil map units are labeled (as space allows) for map scales 1:50,000 or larger .

Date(s) aerial images were photographed: Mar 14, 2022 — Mar 17, 2022
The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps . As a result, some minor shifting of map unit boundaries may be evident.
tile,\ Natural Reso urces
Co nse rva tion Service
Web Soil Survey
National Cooperative Soil Survey
4/1/2024

Hydrologic Soil Group —San Diego County Area, California Hydrologic Soil Group
Map unit symbol
Map unit name
Rating
Acres in AOI
Percent of AOI
hb8n
Bonsall sandy loam, 9 to
15 percent slopes,
eroded
D

0.0 0.0%
hbb8
Diablo clay, 2 to 9
percent slopes
D

1.7 100.0%
Totals for Area of Interest

1.7 100.0%
Description
Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long -duration storms.

The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows:

Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission.

Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture.

These soils have a moderate rate of water transmission.

Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission.

Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink -swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission.

If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. usiD;\ Natural Resources Web Soil Survey
Conservation Service National Cooperative Soil Survey
4/1/2024

08/11/2026
PH2 401 of 876

Hydrologic Soil Group —San Diego County Area, California Rating Options
Aggregation Method: Dominant Condition
Component Percent Cutoff: None Specified
Tie -break Rule: Higher
USDA Natural Resources Web Soil Survey
Conservation Service National Cooperative Soil Survey
4/1/2024

08/11/2026
PH2 402 of 876

County of San Diego
Hydrology Ma nual
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County of San Diego
Hydr ology Manual
be yr ,�. m We Have ti xn Dieg o Covered!

THIS M AP IS PR OVIDE D WH HC UTWRRRRNLY OF TNT KIND, EITHER E XPRESS OR IMPLIED. uTNOT UMITED TO, THE IMPLIED WARRANTIES
OF MERCHA NTABILITY A ND FITNESS FOR A PARTICULAR PURP OSE.

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APPENDIX B -

PRE -DEVELOPMENT

HYDROLOGY CALCULATIONS
08/11/2026
PH2 405 of 876

San Diego County Rational Hydrology Program
CIVILCADD/CIVILDESIGN Engineering Software,(c)1991-2006 Version 7.7 Rational method hydrology program based on
San Diego County Flood Control Division 2003 hydrology manual Rational Hydrology Study Date: 02/24/25
23-299 Pre Development Condition
100 -Year Pre Development
Basin 100-600
Onsite Area
+++
*********
Hydrology Study Control Information **********
Program License Serial Number 6144
Rational hydrology study storm event year is 100.0
English (in -lb) input data Units used
Map data precipitation entered:
6 hour, precipitation(inches) = 3.200
24 hour precipitation(inches) = 5.600
P6/P24 = 57.1%
San Diego hydrology manual 'C' values used
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 101.000 to Point/Station
102.000
**** INITIAL AREA EVALUATION ****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[UNDISTURBED NATURAL TERRAIN
(Permanent Open Space )
Impervious value, Ai = 0.000
Sub -Area C Value = 0.350
Initial subarea total flow distance = 35.000(Ft.)
Highest elevation = 464.880(Ft.)
Lowest elevation = 459.000(Ft.)
08/11/2026
PH2 406 of 876

Elevation difference = 5.880(Ft.) Slope = 16.800 %
Top of Initial Area Slope adjusted by User to 30.000 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:

The maximum overland flow distance is 100.00 (Ft)
for the top area slope value of 30.00 %, in a development type of Permanent Open Space
In Accordance With Figure 3-3
Initial Area Time of Concentration = 4.34 minutes
TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)]
TC = [1.8*(1.1-0.3500)*( 100.000".5)/( 30.000^(1/3)]= 4.34 Calculated TC of 4.345 minutes is less than 5 minutes,
resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 8.431(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.350 Subarea runoff = 0.027(CFS)
Total initial stream area = 0.009(Ac.)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station
202.000
**** INITIAL AREA EVALUATION
201.000 to Point/Station
****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[MEDIUM DENSITY RESIDENTIAL
(4.3 DU/A or Less
Impervious value, Ai = 0.300
Sub -Area C Value = 0.520
Initial subarea total flow distance = 71.000(Ft.)
Highest elevation = 468.000(Ft.)
Lowest elevation = 458.170(Ft.)
Elevation difference = 9.830(Ft.) Slope 13.845 %
Top of Initial Area Slope adjusted by User to 25.000 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:

The maximum overland flow distance is 100.00 (Ft)
for the top area slope value of 25.00 %, in a development type of

4.3 DU/A or Less
In Accordance With Figure 3-3
Initial Area Time of Concentration = 3.57 minutes
TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)]
TC = [1.8*(1.1-0.5200)*( 100.000".5)/( 25.000^(1/3)]= 3.57 Calculated TC of 3.570 minutes is less than 5 minutes,
resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 8.431(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.520 Subarea runoff = 0.614(CFS)
Total initial stream area = 0.140(Ac.)
08/11/2026
PH2 407 of 876

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station
302.000
**** INITIAL AREA EVALUATION
+++
301.000 to Point/Station
* * * *
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[MEDIUM DENSITY RESIDENTIAL
(4.3 DU/A or Less
Impervious value, Ai = 0.300
Sub -Area C Value = 0.520
Initial subarea total flow distance = 92.000(Ft.)
Highest elevation = 467.640(Ft.)
Lowest elevation = 457.430(Ft.)
Elevation difference = 10.210(Ft.) Slope 11.098 %
Top of Initial Area Slope adjusted by User to 11.000 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:

The maximum overland flow distance is 100.00 (Ft)
for the top area slope value of 11.00 %, in a development type of

4.3 DU/A or Less
In Accordance With Figure 3-3
Initial Area Time of Concentration = 4.69 minutes
TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)]
TC = [1.8*(1.1-0.5200)*( 100.000".5)/( 11.000^(1/3)]= 4.69 Calculated TC of 4.694 minutes is less than 5 minutes,
resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 8.431(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.520 Subarea runoff = 0.395(CFS)
Total initial stream area = 0.090(Ac.)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 401.000 to Point/Station
402.000
**** INITIAL AREA EVALUATION ****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[MEDIUM DENSITY RESIDENTIAL
(7.3 DU/A or Less
Impervious value, Ai = 0.400
Sub -Area C Value = 0.570
Initial subarea total flow distance = 116.000(Ft.)
Highest elevation = 467.000(Ft.)
Lowest elevation = 454.530(Ft.)
08/11/2026
PH2 408 of 876

Elevation difference = 12.470(Ft.) Slope = 10.750 %
Top of Initial Area Slope adjusted by User to 11.000 %
Bottom of Initial Area Slope adjusted by User to 11.000 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:

The maximum overland flow distance is 100.00 (Ft)
for the top area slope value of 11.00 %, in a development type of

7.3 DU/A or Less
In Accordance With Figure 3-3
Initial Area Time of Concentration = 4.29 minutes
TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)]
TC = [1.8*(1.1-0.5700)*( 100.000".5)/( 11.000^(1/3)]= 4.29 The initial area total distance of 116.00 (Ft.) entered leaves a remaining distance of 16.00 (Ft.)
Using Figure 3-4, the travel time for this distance is 0.15 minutes
for a distance of 16.00 (Ft.) and a slope of 11.00 %
with an elevation difference of 1.76(Ft.) from the end of the top area
Tt = [11.9*length(Mi)^3)/(elevation change(Ft.))]A.385 *60(min/hr)

0.154 Minutes
Tt=[(11.9*0.0030^3)/( 1.76)]".385= 0.15
Total initial area Ti = 4.29 minutes from Figure 3-3 formula plus

0.15 minutes from the Figure 3-4 formula = 4.44 minutes Calculated TC of 4.444 minutes is less than 5 minutes,
resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 8.431(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.570 Subarea runoff = 0.913(CFS)
Total initial stream area = 0.190(Ac.)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station
502.000
**** INITIAL AREA EVALUATION
501.000 to Point/Station
****
Decimal fraction
Decimal fraction
Decimal fraction
Decimal fraction
[LOW DENSITY
(1.0 DU/A or
soil group A
soil group
soil group
soil group

RESIDENTIAL
Less
B
C
D

0.000

0.000

0.000

1.000
Impervious value, Ai = 0.100
Sub -Area C Value = 0.410
Initial subarea total flow distance = 133.000(Ft.)
Highest elevation = 462.830(Ft.)
Lowest elevation = 451.150(Ft.)
Elevation difference = 11.680(Ft.) Slope 8.782 %
Top of Initial Area Slope adjusted by User to 10.000 %
Bottom of Initial Area Slope adjusted by User to 10.000 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:

The maximum overland flow distance is 100.00 (Ft)
08/11/2026
PH2 409 of 876

for the top area slope value of 10.00 %, in a development type of

1.0 DU/A or Less
In Accordance With Figure 3-3
Initial Area Time of Concentration = 5.76 minutes
TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)]
TC = [1.8*(1.1-0.4100)*( 100.000".5)/( 10.000^(1/3)]= 5.76 The initial area total distance of 133.00 (Ft.) entered leaves a remaining distance of 33.00 (Ft.)
Using Figure 3-4, the travel time for this distance is 0.28 minutes
for a distance of 33.00 (Ft ) and a slope of 10.00 %
with an elevation difference of 3.30(Ft.) from the end of the top area
Tt = [11.9*length(Mi)^3)/(elevation change(Ft.))]^.385 *60(min/hr)

0.280 Minutes
Tt=[(11.9*0.0063^3)/( 3.30)]".385= 0.28
Total initial area Ti = 5.76 minutes from Figure 3-3 formula plus

0.28 minutes from the Figure 3-4 formula = 6.04 minutes Rainfall intensity (I) = 7.460(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.410 Subarea runoff = 0.826(CFS)
Total initial stream area = 0.270(Ac.)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station
602.000
**** INITIAL AREA EVALUATION
601.000 to Point/Station
****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[UNDISTURBED NATURAL TERRAIN
(Permanent Open Space )
Impervious value, Ai = 0.000
Sub -Area C Value = 0.350
Initial subarea total flow distance = 86.000(Ft.)
Highest elevation = 467.990(Ft.)
Lowest elevation = 464.060(Ft.)
Elevation difference = 3.930(Ft.) Slope = 4.570 %
Top of Initial Area Slope adjusted by User to 5.300 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:

The maximum overland flow distance is 100.00 (Ft)
for the top area slope value of 5.30 %, in a development type of Permanent Open Space
In Accordance With Figure 3-3
Initial Area Time of Concentration = 7.74 minutes
TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)]
TC = [1.8* (1.1-0.3500) * ( 100.000".5)/( 5.300A(1/3)]= 7.74 Rainfall intensity (I) = 6.359(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.350 08/11/2026
PH2 410 of 876

Subarea runoff = 0.378(CFS)
Total initial stream area = 0.170(Ac.)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station
603.000
**** SUBAREA FLOW ADDITION ****
602.000 to Point/Station
Rainfall intensity (I) = 6.359(In/Hr) for a 100.0 year storm Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[UNDISTURBED NATURAL TERRAIN
(Permanent Open Space )
Impervious value, Ai = 0.000
Sub -Area C Value = 0.350
Time of concentration = 7.74 min.

Rainfall intensity = 6.359(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.350 CA = 0.339
Subarea runoff = 1.780(CFS) for 0.800(Ac.)
Total runoff = 2.159(CFS) Total area = 0.970(Ac.)
End of computations, total study area = 1.669 (Ac.)
08/11/2026
PH2 411 of 876

APPENDIX C -

POST -DEVELOPMENT

HYDROLOGY CALCULATIONS
08/11/2026
PH2 412 of 876

UNMITIGATED
08/11/2026
PH2 413 of 876

San Diego County Rational Hydrology Program
CIVILCADD/CIVILDESIGN Engineering Software,(c)1991-2006 Version 7.7 Rational method hydrology program based on
San Diego County Flood Control Division 2003 hydrology manual Rational Hydrology Study Date: 03/10/25
23-299 Post Development Condition
100 -Year Post Development
Basins 100-800
Onsite Area
+++
*********
Hydrology Study Control Information **********
Program License Serial Number 6144
Rational hydrology study storm event year is 100.0
English (in -lb) input data Units used
Map data precipitation entered:
6 hour, precipitation(inches) = 3.200
24 hour precipitation(inches) = 5.600
P6/P24 = 57.1%
San Diego hydrology manual 'C' values used
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 101.000 to Point/Station
102.000
**** INITIAL AREA EVALUATION ****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[HIGH DENSITY RESIDENTIAL
(24.0 DU/A or Less
Impervious value, Ai = 0.650
Sub -Area C Value = 0.710
Initial subarea total flow distance = 39.000(Ft.)
Highest elevation = 465.100(Ft.)
Lowest elevation = 464.300(Ft.)
08/11/2026
PH2 414 of 876

Elevation difference = 0.800(Ft.) Slope = 2.051 %
Top of Initial Area Slope adjusted by User to 2.000 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:

The maximum overland flow distance is 75.00 (Ft)
for the top area slope value of 2.00 %, in a development type of

24.0 DU/A or Less
In Accordance With Figure 3-3
Initial Area Time of Concentration = 4.83 minutes
TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)]
TC = [1.8*(1.1-0.7100)*( 75.000^.5)/( 2.000^(1/3)]= 4.83 Calculated TC of 4.825 minutes is less than 5 minutes,
resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 8.431(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = 0.251(CFS)
Total initial stream area = 0.042(Ac.)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station
103.000
**** SUBAREA FLOW ADDITION ****
+++
102.000 to Point/Station
Calculated TC of 4.825 minutes is less than 5 minutes,
resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) =
Decimal fraction soil group A
Decimal fraction soil group B
Decimal fraction soil group C
Decimal fraction soil group D
[UNDISTURBED NATURAL TERRAIN
(Permanent Open Space )
Impervious value, Ai = 0.000
Sub -Area C Value = 0.350
Time of concentration =

8.431(In/Hr)
= 0.000
= 0.000
= 0.000
= 1.000

4.83 min.
for a 100.0 year storm
Rainfall intensity = 8.431(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.458 CA = 0.064
Subarea runoff = 0.289(CFS) for 0.098(Ac.)
Total runoff = 0.541(CFS) Total area = 0.140(Ac.)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 103.000 to Point/Station
104.000
**** PIPEFLOW TRAVEL TIME (User specified size) ****
Upstream point/station elevation = 495.250(Ft.)
Downstream point/station elevation = 495.000(Ft.)
Pipe length = 44.65(Ft.) Slope = 0.0056 Manning's N = 0.009 08/11/2026
PH2 415 of 876

No. of pipes = 1 Required pipe flow = 0.541(CFS)
Given pipe size = 6.00(In.)
Calculated individual pipe flow = 0.541(CFS)
Normal flow depth in pipe = 4.42(In.)
Flow top width inside pipe = 5.29(In.)
Critical Depth = 4.50(In.)
Pipe flow velocity = 3.49(Ft/s)
Travel time through pipe = 0.21 min.

Time of concentration (TC) = 5.04 min.
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station
202.000
**** INITIAL AREA EVALUATION
+++
201.000 to Point/Station
****
Decimal fraction
Decimal fraction
Decimal fraction
Decimal fraction
[LOW DENSITY
(2.0 DU/A or
soil group
soil group
soil group
soil group

RESIDENTIAL
Less
A
B
C
D

0.000

0.000

0.000

1.000
Impervious value, Ai = 0.200
Sub -Area C Value = 0.460
Initial subarea total flow distance = 62.000(Ft.)
Highest elevation = 475.000(Ft.)
Lowest elevation = 459.500(Ft.)
Elevation difference = 15.500(Ft.) Slope 25.000 %
Top of Initial Area Slope adjusted by User to 26.000 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:

The maximum overland flow distance is 100.00 (Ft)
for the top area slope value of 26.00 %, in a development type of

2.0 DU/A or Less
In Accordance With Figure 3-3
Initial Area Time of Concentration = 3.89 minutes
TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)]
TC = [1.8*(1.1-0.4600)*( 100.000".5)/( 26.000^(1/3)]= 3.89 Calculated TC of 3.889 minutes is less than 5 minutes,
resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 8.431(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.460 Subarea runoff = 0.349(CFS)
Total initial stream area = 0.090(Ac.)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station
304.000
**** IMPROVED CHANNEL TRAVEL TIME ****
202.000 to Point/Station
08/11/2026
PH2 416 of 876

Upstream point elevation = 457.450(Ft.)
Downstream point elevation = 456.260(Ft.)
Channel length thru subarea = 47.900(Ft.)
Channel base width = 1.500(Ft.)
Slope or 'Z' of left channel bank = 0.000
Slope or 'Z' of right channel bank = 1.000
Manning's 'N' = 0.015
Maximum depth of channel = 0.330(Ft.)
Flow(q) thru subarea = 0.349(CFS)
Depth of flow = 0.082(Ft.), Average velocity
Channel flow top width = 1.582(Ft.)
Flow Velocity = 2.76(Ft/s)
Travel time = 0.29 min.

Time of concentration = 4.18 min.

Critical depth = 0.117(Ft.)

2.762(Ft/s)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station 202.000 to Point/Station
304.000
**** CONFLUENCE OF MINOR STREAMS ****
Along Main Stream number: 1 in normal stream number 1
Stream flow area = 0.090(Ac.)
Runoff from this stream = 0.349(CFS)
Time of concentration = 4.18 min.

Rainfall intensity = 8.431(In/Hr)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station
302.000
**** INITIAL AREA EVALUATION
301.000 to Point/Station
****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[MEDIUM DENSITY RESIDENTIAL
(14.5 DU/A or Less
Impervious value, Ai = 0.500
Sub -Area C Value = 0.630
Initial subarea total flow distance = 50.000(Ft.)
Highest elevation = 465.100(Ft.)
Lowest elevation = 464.000(Ft.)
Elevation difference = 1.100(Ft.) Slope = 2.200 %
Top of Initial Area Slope adjusted by User to 2.000 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:

The maximum overland flow distance is 80.00 (Ft)
for the top area slope value of 2.00 %, in a development type of 08/11/2026
PH2 417 of 876

14.5 DU/A or Less
In Accordance With Figure 3-3
Initial Area Time of Concentration = 6.01 minutes
TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)]
TC = [1.8*(1.1-0.6300)*( 80.000".5)/( 2.000^(1/3)]=
Rainfall intensity (I) = 7.491(In/Hr) for a 100.0
Effective runoff coefficient used for area (Q=KCIA) is C Subarea runoff = 0.250(CFS)
Total initial stream area = 0.053(Ac.)

6.01 year storm
= 0.630
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station
303.000
**** SUBAREA FLOW ADDITION ****
+++
302.000 to Point/Station
Rainfall intensity (I) = 7.491(In/Hr) for a 100.0 year storm User specified 'C' value of 0.760 given for subarea
Time of concentration = 6.01 min.

Rainfall intensity = 7.491(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.697 CA = 0.077
Subarea runoff = 0.325(CFS) for 0.057(Ac.)
Total runoff = 0.575(CFS) Total area = 0.110(Ac.)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 303.000 to Point/Station
304.000
**** PIPEFLOW TRAVEL TIME (User specified size) ****
+++
Upstream point/station elevation =
Downstream point/station elevation =
Pipe length = 22.40(Ft.) Slope =
No. of pipes = 1 Required pipe flow
Given pipe size = 6.00(In.)
Calculated individual pipe flow = 0.575(CFS)
Normal flow depth in pipe = 2.40(In.)
Flow top width inside pipe = 5.88(In.)
Critical Depth = 4.63(In.)
Pipe flow velocity = 7.83(Ft/s)
Travel time through pipe = 0.05 min.

Time of concentration (TC) = 6.05 min
457.250(Ft.)
456.260(Ft.)

0.0442 Manning's N = 0.009

0.575(CFS)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station
304.000
**** CONFLUENCE OF MINOR STREAMS ****
303.000 to Point/Station
08/11/2026
PH2 418 of 876

Along Main Stream number: 1 in normal stream number 2
Stream flow area = 0.110(Ac.)
Runoff from this stream = 0.575(CFS)
Time of concentration =
Rainfall intensity =
Summary of stream data:

6.05 min.

7.453(In/Hr)
Stream Flow rate TC
No. (CFS) (min)
1 2
Qmax (1)

1.000

1.000
Qmax(2) _

0.884

1.000

0.349

0.575

4.18 6.05
* 1.000 *
* 0.690 *
* 1.000 *
* 1.000 *
Rainfall Intensity
(In/Hr)

8.431

7.453

0.349) +

0.575) +

0.349) +

0.575) +

0.746

0.883
Total of 2 streams to confluence:

Flow rates before confluence point:

0.349 0.575
Maximum flow rates at confluence using above data:

0.746 0.883
Area of streams before confluence:

0.090 0.110
Results of confluence:

Total flow rate = 0.883(CFS)
Time of concentration = 6.053 min.

Effective stream area after confluence = 0.200(Ac.)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station
402.000
**** INITIAL AREA EVALUATION
401.000 to Point/Station
****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[UNDISTURBED NATURAL TERRAIN
(Permanent Open Space )
Impervious value, Ai = 0.000
Sub -Area C Value = 0.350
Initial subarea total flow distance = 23.000(Ft.)
Highest elevation = 462.300(Ft.)
Lowest elevation = 458.000(Ft.)
Elevation difference = 4.300(Ft.) Slope 18.696 %
08/11/2026
PH2 419 of 876

Top of Initial Area Slope adjusted by User to 19.200 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:

The maximum overland flow distance is 100.00 (Ft)
for the top area slope value of 19.20 %, in a development type of Permanent Open Space
In Accordance With Figure 3-3
Initial Area Time of Concentration = 5.04 minutes
TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)]
TC = [1.8*(1.1-0.3500)*( 100.000^.5)/( 19.200"(1/3)]= 5.04 Rainfall intensity (I) = 8.386(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.350 Subarea runoff = 0.112(CFS)
Total initial stream area = 0.038(Ac.)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station
404.000
**** INITIAL AREA EVALUATION
+++
403.000 to Point/Station
****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[UNDISTURBED NATURAL TERRAIN
(Permanent Open Space )
Impervious value, Ai = 0.000
Sub -Area C Value = 0.350
Initial subarea total flow distance = 13.000(Ft.)
Highest elevation = 459.600(Ft.)
Lowest elevation = 453.500(Ft.)
Elevation difference = 6.100(Ft.) Slope 46.923 %
Top of Initial Area Slope adjusted by User to 30.000 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:

The maximum overland flow distance is 100.00 (Ft)
for the top area slope value of 30.00 %, in a development type of Permanent Open Space
In Accordance With Figure 3-3
Initial Area Time of Concentration = 4.34 minutes
TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)]
TC = [1.8*(1.1-0.3500)*( 100.000".5)/( 30.000^(1/3)]= 4.34 Calculated TC of 4.345 minutes is less than 5 minutes,
resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 8.431(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.350 Subarea runoff = 0.065(CFS)
Total initial stream area = 0.022(Ac.)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 08/11/2026
PH2 420 of 876

Process from Point/Station
406.000
**** INITIAL AREA EVALUATION
+++
405.000 to Point/Station
****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[UNDISTURBED NATURAL TERRAIN
(Permanent Open Space )
Impervious value, Ai = 0.000
Sub -Area C Value = 0.350
Initial subarea total flow distance = 16.000(Ft.)
Highest elevation = 461.000(Ft.)
Lowest elevation = 452.100(Ft.)
Elevation difference = 8.900(Ft.) Slope 55.625 %
Top of Initial Area Slope adjusted by User to 30.000 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:

The maximum overland flow distance is 100.00 (Ft)
for the top area slope value of 30.00 %, in a development type of Permanent Open Space
In Accordance With Figure 3-3
Initial Area Time of Concentration = 4.34 minutes
TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slopeA(1/3)]
TC = [1.8*(1.1-0.3500)*( 100.000".5)/( 30.000^(1/3)]= 4.34 Calculated TC of 4.345 minutes is less than 5 minutes,
resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 8.431(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.350 Subarea runoff = 0.083(CFS)
Total initial stream area = 0.028(Ac.)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 501.000 to Point/Station
502.000
**** INITIAL AREA EVALUATION ****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[INDUSTRIAL area type
(General Industrial
Impervious value, Ai = 0.950
Sub -Area C Value = 0.870
Initial subarea total flow distance = 45.000(Ft.)
Highest elevation = 463.200(Ft.)
Lowest elevation = 462.200(Ft.)
Elevation difference = 1.000(Ft.) Slope = 2.222 %
Top of Initial Area Slope adjusted by User to 2.000 %
08/11/2026
PH2 421 of 876

INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:

The maximum overland flow distance is 70.00 (Ft)
for the top area slope value of 2.00 %, in a development type of General Industrial
In Accordance With Figure 3-3
Initial Area Time of Concentration = 2.75 minutes
TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(o slope^(1/3)]
TC = [1.8*(1.1-0.8700)*( 70.000".5)/( 2.000^(1/3)]= 2.75 Calculated TC of 2.749 minutes is less than 5 minutes,
resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 8.431(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.870 Subarea runoff = 0.587(CFS)
Total initial stream area = 0.080(Ac.)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station
503.000
**** SUBAREA FLOW ADDITION
+++
502.000 to Point/Station
* * * *
Calculated TC of 2.749 minutes is less than 5 minutes,
resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 8.431(In/Hr) for a 100.0 year storm Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[HIGH DENSITY RESIDENTIAL
(43.0 DU/A or Less
Impervious value, Ai = 0.800
Sub -Area C Value = 0.790
Time of concentration = 2.75 min.

Rainfall intensity = 8.431(In/Hr) for a 100 0 year storm Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.815 CA = 0.212
Subarea runoff = 1.199(CFS) for 0.180(Ac.)
Total runoff = 1.786(CFS) Total area = 0.260(Ac.)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 503.000 to Point/Station
603.000
**** PIPEFLOW TRAVEL TIME (User specified size) ****
Upstream point/station elevation = 455.250(Ft.)
Downstream point/station elevation = 450.500(Ft.)
Pipe length = 255.11(Ft.) Slope = 0.0186 Manning's N = 0.009 No. of pipes = 1 Required pipe flow = 1.786(CFS)
Given pipe size = 10.00(In.)
08/11/2026
PH2 422 of 876

Calculated individual pipe flow = 1.786(CFS)
Normal flow depth in pipe = 4.48(In.)
Flow top width inside pipe = 9.95(In.)
Critical Depth = 7.20(In.)
Pipe flow velocity = 7.54(Ft/s)
Travel time through pipe = 0.56 min.

Time of concentration (TC) = 3.31 min.
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station
603.000
**** CONFLUENCE OF MINOR STREAMS
+++
503.000 to Point/Station
****
Along Main Stream number: 1 in normal stream number 1
Stream flow area = 0.260(Ac.)
Runoff from this stream = 1.786(CFS)
Time of concentration = 3.31 min.

Rainfall intensity = 8.431(In/Hr)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station
602.000
**** INITIAL AREA EVALUATION
601.000 to Point/Station
****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[MEDIUM DENSITY RESIDENTIAL
(7.3 DU/A or Less
Impervious value, Ai = 0.400
Sub -Area C Value = 0.570
Initial subarea total flow distance = 49.000(Ft.)
Highest elevation = 457.800(Ft.)
Lowest elevation = 455.500(Ft.)
Elevation difference = 2.300(Ft.) Slope = 4.694 %
Top of Initial Area Slope adjusted by User to 4.000 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:

The maximum overland flow distance is 100.00 (Ft)
for the top area slope value of 4.00 %, in a development type of

7.3 DU/A or Less
In Accordance With Figure 3-3
Initial Area Time of Concentration = 6.01 minutes
TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)]
TC = [1.8*(1.1-0.5700)*( 100.000".5)/( 4.000^(1/3)]= 6.01 Rainfall intensity (I) = 7.488(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.570 Subarea runoff = 0.726(CFS)
08/11/2026
PH2 423 of 876

Total initial stream area = 0.170(Ac.)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station 602.000 to Point/Station
603.000
**** PIPEFLOW TRAVEL TIME (User specified size) ****
Upstream point/station elevation = 450.750(Ft.)
Downstream point/station elevation = 450.500(Ft.)
Pipe length = 95.60(Ft.) Slope = 0.0026 Manning's N = 0.009 No. of pipes = 1 Required pipe flow = 0.726(CFS)
Given pipe size = 10.00(In.)
Calculated individual pipe flow = 0.726(CFS)
Normal flow depth in pipe = 4.69(In.)
Flow top width inside pipe = 9.98(In.)
Critical Depth = 4.51(In.)
Pipe flow velocity = 2.89(Ft/s)
Travel time through pipe = 0.55 min.

Time of concentration (TC) = 6.56 min.
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station
603.000
**** CONFLUENCE OF MINOR STREAMS
603.000 to Point/Station
****
Along Main Stream number: 1 in normal stream number 2
Stream flow area = 0.170(Ac.)
Runoff from this stream = 0.726(CFS)
Time of concentration = 6.56 min.

Rainfall intensity = 7.075(In/Hr)
Summary of stream data:

Stream Flow rate TC
No. (CFS) (min)
Rainfall Intensity
(In/Hr)
1 1.786 3.31 8.431
2 0.726 6.56 7.075
Qmax(1) =

1.000 * 1.000 * 1.786) +

1.000 * 0.505 * 0.726) + = 2.152
Qmax(2) =

0.839 * 1.000 * 1.786) +

1.000 * 1.000 * 0.726) + = 2.224
Total of 2 streams to confluence:

Flow rates before confluence point:

1.786 0.726
08/11/2026
PH2 424 of 876

Maximum flow rates at confluence using above data:

2.152 2.224
Area of streams before confluence:

0.260 0.170
Results of confluence:

Total flow rate = 2.224(CFS)
Time of concentration = 6.562 min.

Effective stream area after confluence = 0.430(Ac.)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +
Process from Point/Station 603.000 to Point/Station
703.000
**** PIPEFLOW TRAVEL TIME (User specified size) ****
Upstream point/station elevation = 450.500(Ft.)
Downstream point/station elevation = 450.170(Ft.)
Pipe length = 109.32(Ft.) Slope = 0.0030 Manning's N = 0.009 No. of pipes = 1 Required pipe flow = 2.224(CFS)
Given pipe size = 10.00(In.)
NOTE: Normal flow is pressure flow in user selected pipe size.

The approximate hydraulic grade line above the pipe invert is

0.597(Ft.) at the headworks or inlet of the pipe(s)
Pipe friction loss = 0.540(Ft.)
Minor friction loss = 0.387(Ft.) K -factor = 1.50
Pipe flow velocity = 4.08(Ft/s)
Travel time through pipe = 0.45 min.

Time of concentration (TC) = 7.01 min.
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station 603.000 to Point/Station
703.000
**** CONFLUENCE OF MINOR STREAMS ****
Along Main Stream number: 1 in normal stream number 1
Stream flow area = 0.430(Ac.)
Runoff from this stream = 2.224(CFS)
Time of concentration = 7.01 min.

Rainfall intensity = 6.781(In/Hr)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station
702.000
**** INITIAL AREA EVALUATION
701.000 to Point/Station
* * * *
Decimal fraction soil group A = 0.000
08/11/2026
PH2 425 of 876

Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[HIGH DENSITY RESIDENTIAL
(43.0 DU/A or Less
Impervious value, Ai = 0.800
Sub -Area C Value = 0.790
Initial subarea total flow distance = 45.000(Ft.)
Highest elevation = 465.100(Ft.)
Lowest elevation = 463.200(Ft.)
Elevation difference = 1.900(Ft.) Slope = 4.222 %
Top of Initial Area Slope adjusted by User to 4.200 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:

The maximum overland flow distance is 95.00 (Ft)
for the top area slope value of 4.20 %, in a development type of

43.0 DU/A or Less
In Accordance With Figure 3-3
Initial Area Time of Concentration = 3.37 minutes
TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)]
TC = [1.8*(1.1-0.7900)*( 95.000".5)/( 4.200^(1/3)]= 3.37 Calculated TC of 3.371 minutes is less than 5 minutes,
resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 8.431(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.790 Subarea runoff = 1.066(CFS)
Total initial stream area = 0.160(Ac.)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station
703.000
**** SUBAREA FLOW ADDITION ****
+++
702.000 to Point/Station
Calculated TC of 3.371 minutes is less than 5 minutes,
resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 8.431(In/Hr) for a 100.0 year storm User specified 'C' value of 0.730 given for subarea
Time of concentration = 3.37 min.

Rainfall intensity = 8.431(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.742 CA = 0.579
Subarea runoff = 3.816(CFS) for 0.620(Ac.)
Total runoff = 4.882(CFS) Total area = 0.780(Ac.)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 703.000 to Point/Station
703.000
**** CONFLUENCE OF MINOR STREAMS ****
08/11/2026
PH2 426 of 876

Along Main Stream number: 1 in normal stream number 2
Stream flow area = 0.780(Ac.)
Runoff from this stream = 4.882(CFS)
Time of concentration = 3.37 min.

Rainfall intensity = 8.431(In/Hr)
Summary of stream data:

Stream
No.
1 2
Qmax (1)
Qmax (2)
Flow rate
(CFS)

2.224

4.882

1.000

0.804

1.000

1.000
TC
(min)

7.01 3.37
* 1.000 *
* 1.000 *
* 0.481 *
* 1.000 *
Rainfall Intensity
(In/Hr)

6.781

8.431

2.224) +

4.882) +

2.224) +

4.882) +

6.150

5.951
Total of 2 streams to confluence:

Flow rates before confluence point:

2.224 4.882
Maximum flow rates at confluence using above data:

6.150 5.951
Area of streams before confluence:

0.430 0.780
Results of confluence:

Total flow rate = 6.150(CFS)
Time of concentration = 7.009 min.

Effective stream area after confluence = 1.210(Ac.)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station
704 000
**** PIPEFLOW TRAVEL TIME (User specified size) ****
703.000 to Point/Station
Upstream point/station elevation =
Downstream point/station elevation =
Pipe length = 7.98(Ft.) Slope =
No. of pipes = 1 Required pipe flow
Given pipe size = 12.00(In.)
Calculated individual pipe flow = 6.150(CFS)
Normal flow depth in pipe = 8.26(In.)
Flow top width inside pipe = 11.11(In.)
Critical depth could not be calculated.

Pipe flow velocity = 10.67(Ft/s)
Travel time through pipe = 0.01 min.

Time of concentration (TC) = 7.02 min.
450.170(Ft.)
450.000(Ft.)

0.0213 Manning's N = 0.009

6.150(CFS)
08/11/2026
PH2 427 of 876

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station
802.000
**** INITIAL AREA EVALUATION
801.000 to Point/Station
* * * *
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[UNDISTURBED NATURAL TERRAIN
(Permanent Open Space )
Impervious value, Ai = 0.000
Sub -Area C Value = 0.350
Initial subarea total flow distance = 16.000(Ft.)
Highest elevation = 457.700(Ft.)
Lowest elevation = 450.500(Ft.)
Elevation difference = 7.200(Ft.) Slope 45.000 %
Top of Initial Area Slope adjusted by User to 30.000 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:

The maximum overland flow distance is 100.00 (Ft)
for the top area slope value of 30.00 %, in a development type of Permanent Open Space
In Accordance With Figure 3-3
Initial Area Time of Concentration = 4.34 minutes
TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)]
TC = [1.8*(1.1-0.3500)*( 100.000".5)/( 30.000^(1/3)]= 4.34 Calculated TC of 4.345 minutes is less than 5 minutes,
resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 8.431(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.350 Subarea runoff = 0.091(CFS)
Total initial stream area = 0.031(Ac.)
End of computations, total study area = 1.669 (Ac.)
08/11/2026
PH2 428 of 876

MITIGATED
08/11/2026
PH2 429 of 876

San Diego County Rational Hydrology Program
CIVILCADD/CIVILDESIGN Engineering Software,(c)1991-2006 Version 7.7 Rational method hydrology program based on
San Diego County Flood Control Division 2003 hydrology manual Rational Hydrology Study Date: 03/13/25
23-299 Post Development Condition
100 -Year Post Development
Basins 100-800
Onsite Area
+++
*********
Hydrology Study Control Information **********
Program License Serial Number 6144
Rational hydrology study storm event year is 100.0
English (in -lb) input data Units used
Map data precipitation entered:
6 hour, precipitation(inches) = 3.200
24 hour precipitation(inches) = 5.600
P6/P24 = 57.1%
San Diego hydrology manual 'C' values used
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 101.000 to Point/Station
102.000
**** INITIAL AREA EVALUATION ****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[HIGH DENSITY RESIDENTIAL
(24.0 DU/A or Less
Impervious value, Ai = 0.650
Sub -Area C Value = 0.710
Initial subarea total flow distance = 39.000(Ft.)
Highest elevation = 465.100(Ft.)
Lowest elevation = 464.300(Ft.)
08/11/2026
PH2 430 of 876

Elevation difference = 0.800(Ft.) Slope = 2.051 %
Top of Initial Area Slope adjusted by User to 2.000 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:

The maximum overland flow distance is 75.00 (Ft)
for the top area slope value of 2.00 %, in a development type of

24.0 DU/A or Less
In Accordance With Figure 3-3
Initial Area Time of Concentration = 4.83 minutes
TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)]
TC = [1.8*(1.1-0.7100)*( 75.000^.5)/( 2.000^(1/3)]= 4.83 Calculated TC of 4.825 minutes is less than 5 minutes,
resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 8.431(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = 0.251(CFS)
Total initial stream area = 0.042(Ac.)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station
103.000
**** SUBAREA FLOW ADDITION ****
+++
102.000 to Point/Station
Calculated TC of 4.825 minutes is less than 5 minutes,
resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) =
Decimal fraction soil group A
Decimal fraction soil group B
Decimal fraction soil group C
Decimal fraction soil group D
[UNDISTURBED NATURAL TERRAIN
(Permanent Open Space )
Impervious value, Ai = 0.000
Sub -Area C Value = 0.350
Time of concentration =

8.431(In/Hr)
= 0.000
= 0.000
= 0.000
= 1.000

4.83 min.
for a 100.0 year storm
Rainfall intensity = 8.431(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.458 CA = 0.064
Subarea runoff = 0.289(CFS) for 0.098(Ac.)
Total runoff = 0.541(CFS) Total area = 0.140(Ac.)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 103.000 to Point/Station
104.000
**** USER DEFINED FLOW INFORMATION AT A POINT ****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
08/11/2026
PH2 431 of 876

Decimal fraction soil group D = 1.000
[HIGH DENSITY RESIDENTIAL
(24.0 DU/A or Less
Impervious value, Ai = 0.650
Sub -Area C Value = 0.710
Rainfall intensity (I) = 8.431(In/Hr) for a 100.0 year storm User specified values are as follows:

TC = 5.00 min. Rain intensity = 8.43(In/Hr)
Total area = 0.014(Ac.) Total runoff = 0.370(CFS)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station 103.000 to Point/Station
104.000
**** PIPEFLOW TRAVEL TIME (User specified size) ****
Upstream point/station elevation =
Downstream point/station elevation =
Pipe length = 44.65(Ft.) Slope =
No. of pipes = 1 Required pipe flow
Given pipe size = 6.00(In.)
Calculated individual pipe flow =
Normal flow depth in pipe =
Flow top width inside pipe =
Critical Depth = 3.71(In.)
Pipe flow velocity = 3.24(Ft/s)
Travel time through pipe = 0.23 min.

Time of concentration (TC) = 5.23 min.
495.250(Ft.)
495.000(Ft.)

0.0056 Manning's N = 0.009

0.370(CFS)

0.370(CFS)

3.39(In.)

5.95(In.)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station
202.000
**** INITIAL AREA EVALUATION ****
201.000 to Point/Station
Decimal fraction soil group
Decimal fraction soil group
Decimal fraction soil group
Decimal fraction soil group
[LOW DENSITY RESIDENTIAL
(2.0 DU/A or Less
Impervious value, Ai = 0.200
Sub -Area C Value = 0.460
Initial subarea total flow distance = 62.000(Ft.)
Highest elevation = 475.000(Ft.)
Lowest elevation = 459.500(Ft.)
Elevation difference = 15.500(Ft.) Slope 25.000 %
Top of Initial Area Slope adjusted by User to 26.000 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:

The maximum overland flow distance is 100.00 (Ft)
A
B
C
D

0.000

0.000

0.000

1.000
08/11/2026
PH2 432 of 876

for the top area slope value of 26.00 %, in a development type of

2.0 DU/A or Less
In Accordance With Figure 3-3
Initial Area Time of Concentration = 3.89 minutes
TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(o slope^(1/3)]
TC = [1.8*(1.1-0.4600)*( 100.000".5)/( 26.000^(1/3)]= 3.89 Calculated TC of 3.889 minutes is less than 5 minutes,
resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 8.431(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.460 Subarea runoff = 0.349(CFS)
Total initial stream area = 0.090(Ac.)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station 202.000 to Point/Station
304.000
**** IMPROVED CHANNEL TRAVEL TIME ****
Upstream point elevation = 457.450(Ft.)
Downstream point elevation = 456.260(Ft.)
Channel length thru subarea = 47.900(Ft.)
Channel base width = 1.500(Ft.)
Slope or 'Z' of left channel bank = 0.000
Slope or 'Z' of right channel bank = 1.000
Manning's 'N' = 0.015
Maximum depth of channel = 0.330(Ft.)
Flow(q) thru subarea = 0.349(CFS)
Depth of flow = 0.082(Ft.), Average velocity
Channel flow top width = 1.582(Ft.)
Flow Velocity = 2.76(Ft/s)
Travel time = 0.29 min.

Time of concentration = 4.18 min.

Critical depth = 0.117(Ft.)

2.762(Ft/s)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station 202.000 to Point/Station
304.000
**** CONFLUENCE OF MINOR STREAMS ****
Along Main Stream number: 1 in normal stream number 1
Stream flow area = 0.090(Ac.)
Runoff from this stream = 0.349(CFS)
Time of concentration = 4.18 min.

Rainfall intensity = 8.431(In/Hr)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
08/11/2026
PH2 433 of 876

Process from Point/Station
302.000
**** INITIAL AREA EVALUATION
+++
301.000 to Point/Station
****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[MEDIUM DENSITY RESIDENTIAL
(14.5 DU/A or Less
Impervious value, Ai = 0.500
Sub -Area C Value = 0.630
Initial subarea total flow distance = 50.000(Ft.)
Highest elevation = 465.100(Ft.)
Lowest elevation = 464.000(Ft.)
Elevation difference = 1.100(Ft.) Slope = 2.200 %
Top of Initial Area Slope adjusted by User to 2.000 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:

The maximum overland flow distance is 80.00 (Ft)
for the top area slope value of 2.00 %, in a development type of

14.5 DU/A or Less
In Accordance With Figure 3-3
Initial Area Time of Concentration = 6.01 minutes
TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)]
TC = [1.8*(1.1-0.6300)*( 80.000".5)/( 2.000^(1/3)]= 6.01 Rainfall intensity (I) = 7.491(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.630 Subarea runoff = 0.250(CFS)
Total initial stream area = 0.053(Ac.)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station
303.000
**** SUBAREA FLOW ADDITION ****
+++
302.000 to Point/Station
Rainfall intensity (I) = 7.491(In/Hr) for a 100.0 year storm User specified 'C' value of 0.760 given for subarea
Time of concentration = 6.01 min.

Rainfall intensity = 7.491(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.697 CA = 0.077
Subarea runoff = 0.325(CFS) for 0.057(Ac.)
Total runoff = 0.575(CFS) Total area = 0.110(Ac.)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 303.000 to Point/Station
304.000
**** USER DEFINED FLOW INFORMATION AT A POINT ****
08/11/2026
PH2 434 of 876

User specified 'C' value of 0.760 given for subarea
Rainfall intensity (I) = 7.496(In/Hr) for a 100.0 year storm User specified values are as follows:

TC = 6.00 min. Rain intensity = 7.50(In/Hr)
Total area =

0.110(Ac.) Total runoff = 0.360(CFS)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station 303.000 to Point/Station
304.000
**** PIPEFLOW TRAVEL TIME (User specified size) ****
Upstream point/station elevation = 457.250(Ft.)
Downstream point/station elevation = 456.260(Ft.)
Pipe length = 22.40(Ft.) Slope = 0.0442 Manning's N = 0.009 No. of pipes = 1 Required pipe flow = 0.360(CFS)
Given pipe size = 6.00(In.)
Calculated individual pipe flow = 0.360(CFS)
Normal flow depth in pipe = 1.87(In.)
Flow top width inside pipe = 5.56(In.)
Critical Depth = 3.65(In.)
Pipe flow velocity = 6.88(Ft/s)
Travel time through pipe = 0.05 min.

Time of concentration (TC) = 6.05 min
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station 303.000 to Point/Station
304.000
**** CONFLUENCE OF MINOR STREAMS ****
Along Main Stream number: 1 in normal stream number 2
Stream flow area = 0.110(Ac.)
Runoff from this stream = 0.360(CFS)
Time of concentration = 6.05 min.

Rainfall intensity = 7.452(In/Hr)
Summary of stream data:

Stream Flow rate TC
No. (CFS) (min)
Rainfall Intensity
(In/Hr)
1 0.349 4.18 8.431
2 0.360 6.05 7.452
Qmax(1) =

1.000 * 1.000 * 0.349) +

1.000 * 0.690 * 0.360) + =
Qmax(2) =

0.597
08/11/2026
PH2 435 of 876

0.884 * 1.000 * 0.349) +

1.000 * 1.000 * 0.360) + =

0.669
Total of 2 streams to confluence:

Flow rates before confluence point:

0.349 0.360
Maximum flow rates at confluence using above data:

0.597 0.669
Area of streams before confluence:

0.090 0.110
Results of confluence:

Total flow rate = 0.669(CFS)
Time of concentration = 6.054 min.

Effective stream area after confluence = 0.200(Ac.)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station
402.000
**** INITIAL AREA EVALUATION
+++
401.000 to Point/Station
****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[UNDISTURBED NATURAL TERRAIN
(Permanent Open Space )
Impervious value, Ai = 0.000
Sub -Area C Value = 0.350
Initial subarea total flow distance = 23.000(Ft.)
Highest elevation = 462.300(Ft.)
Lowest elevation = 458.000(Ft.)
Elevation difference = 4.300(Ft.) Slope 18.696 %
Top of Initial Area Slope adjusted by User to 19.200 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:

The maximum overland flow distance is 100.00 (Ft)
for the top area slope value of 19.20 %, in a development type of Permanent Open Space
In Accordance With Figure 3-3
Initial Area Time of Concentration = 5.04 minutes
TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)]
TC = [1.8*(1.1-0.3500)*( 100.000".5)/( 19.200^(1/3)]= 5.04 Rainfall intensity (I) = 8.386(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.350 Subarea runoff = 0.112(CFS)
Total initial stream area = 0.038(Ac.)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 403.000 to Point/Station
404.000
08/11/2026
PH2 436 of 876

**** INITIAL AREA EVALUATION ****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[UNDISTURBED NATURAL TERRAIN
(Permanent Open Space )
Impervious value, Ai = 0.000
Sub -Area C Value = 0.350
Initial subarea total flow distance = 13.000(Ft.)
Highest elevation = 459.600(Ft.)
Lowest elevation = 453.500(Ft.)
Elevation difference = 6.100(Ft.) Slope 46.923 %
Top of Initial Area Slope adjusted by User to 30.000 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:

The maximum overland flow distance is 100.00 (Ft)
for the top area slope value of 30.00 %, in a development type of Permanent Open Space
In Accordance With Figure 3-3
Initial Area Time of Concentration = 4.34 minutes
TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)]
TC = [1.8*(1.1-0.3500)*( 100.000".5)/( 30.000^(1/3)]= 4.34 Calculated TC of 4.345 minutes is less than 5 minutes,
resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 8.431(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.350 Subarea runoff = 0.065(CFS)
Total initial stream area = 0.022(Ac.)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station
406.000
**** INITIAL AREA EVALUATION
405.000 to Point/Station
****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[UNDISTURBED NATURAL TERRAIN
(Permanent Open Space )
Impervious value, Ai = 0.000
Sub -Area C Value = 0.350
Initial subarea total flow distance = 16.000(Ft.)
Highest elevation = 461.000(Ft.)
Lowest elevation = 452.100(Ft.)
Elevation difference = 8.900(Ft.) Slope 55.625 %
Top of Initial Area Slope adjusted by User to 30.000 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:

The maximum overland flow distance is 100.00 (Ft)
08/11/2026
PH2 437 of 876

for the top area slope value of 30.00 %, in a development type of Permanent Open Space
In Accordance With Figure 3-3
Initial Area Time of Concentration = 4.34 minutes
TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)]
TC = [1.8*(1.1-0.3500)*( 100.000".5)/( 30.000^(1/3)]= 4.34 Calculated TC of 4.345 minutes is less than 5 minutes,
resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 8.431(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.350 Subarea runoff = 0.083(CFS)
Total initial stream area = 0.028(Ac.)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station
502.000
**** INITIAL AREA EVALUATION
+++
501.000 to Point/Station
****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[INDUSTRIAL area type
(General Industrial
Impervious value, Ai = 0.950
Sub -Area C Value = 0.870
Initial subarea total flow distance = 45.000(Ft.)
Highest elevation = 463.200(Ft.)
Lowest elevation = 462.200(Ft.)
Elevation difference = 1.000(Ft.) Slope = 2.222 %
Top of Initial Area Slope adjusted by User to 2.000 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:

The maximum overland flow distance is 70.00 (Ft)
for the top area slope value of 2.00 %, in a development type of General Industrial
In Accordance With Figure 3-3
Initial Area Time of Concentration = 2.75 minutes
TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)]
TC = [1.8*(1.1-0.8700)*( 70.000".5)/( 2.000"(1/3)]= 2.75 Calculated TC of 2.749 minutes is less than 5 minutes,
resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 8.431(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.870 Subarea runoff = 0.587(CFS)
Total initial stream area = 0.080(Ac.)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 502.000 to Point/Station
503.000
08/11/2026
PH2 438 of 876

**** SUBAREA FLOW ADDITION ****
Calculated TC of 2.749 minutes is less than 5 minutes,
resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 8.431(In/Hr) for a 100.0 year storm Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[HIGH DENSITY RESIDENTIAL
(43.0 DU/A or Less
Impervious value, Ai = 0.800
Sub -Area C Value = 0.790
Time of concentration = 2.75 min.

Rainfall intensity = 8.431(In/Hr) for a 100 0 year storm Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.815 CA = 0.212
Subarea runoff = 1.199(CFS) for 0.180(Ac.)
Total runoff = 1.786(CFS) Total area = 0.260(Ac.)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station 503.000 to Point/Station
603.000
**** USER DEFINED FLOW INFORMATION AT A POINT ****
User specified 'C' value of 0.790 given for subarea
Rainfall intensity (I) = 8.431(In/Hr) for a 100.0 year storm User specified values are as follows:

TC = 5.00 min. Rain intensity = 8.43(In/Hr)
Total area = 0.260(Ac.) Total runoff = 1.010(CFS)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station 503.000 to Point/Station
603.000
**** PIPEFLOW TRAVEL TIME (User specified size) ****
Upstream point/station elevation = 455.250(Ft.)
Downstream point/station elevation = 450.500(Ft.)
Pipe length = 255.11(Ft.) Slope = 0.0186 Manning's N = 0.009 No. of pipes = 1 Required pipe flow = 1.010(CFS)
Given pipe size = 10.00(In.)
Calculated individual pipe flow = 1.010(CFS)
Normal flow depth in pipe = 3.29(In.)
Flow top width inside pipe = 9.40(In.)
Critical Depth = 5.35(In.)
Pipe flow velocity = 6.46(Ft/s)
Travel time through pipe = 0.66 min.
08/11/2026
PH2 439 of 876

Time of concentration (TC) = 5.66 min.
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station 503.000 to Point/Station
603.000
**** CONFLUENCE OF MINOR STREAMS ****
Along Main Stream number: 1 in normal stream number 1
Stream flow area = 0.260(Ac.)
Runoff from this stream = 1.010(CFS)
Time of concentration = 5.66 min.

Rainfall intensity = 7.785(In/Hr)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station
602.000
**** INITIAL AREA EVALUATION
+++
601.000 to Point/Station
****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[MEDIUM DENSITY RESIDENTIAL
(7.3 DU/A or Less
Impervious value, Ai = 0.400
Sub -Area C Value = 0.570
Initial subarea total flow distance = 49.000(Ft.)
Highest elevation = 457.800(Ft.)
Lowest elevation = 455.500(Ft.)
Elevation difference = 2.300(Ft.) Slope = 4.694 %
Top of Initial Area Slope adjusted by User to 4.000 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:

The maximum overland flow distance is 100.00 (Ft)
for the top area slope value of 4.00 %, in a development type of

7.3 DU/A or Less
In Accordance With Figure 3-3
Initial Area Time of Concentration = 6.01 minutes
TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)]
TC = [1.8*(1.1-0.5700)*( 100.000^.5)/( 4.000^(1/3)]= 6.01 Rainfall intensity (I) = 7.488(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.570 Subarea runoff = 0.726(CFS)
Total initial stream area = 0.170(Ac.)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 08/11/2026
PH2 440 of 876

Process from Point/Station 602.000 to Point/Station
603.000
**** USER DEFINED FLOW INFORMATION AT A POINT ****
User specified 'C' value of 0.570 given for subarea
Rainfall intensity (I) = 7.496(In/Hr) for a 100.0 year storm User specified values are as follows:

TC = 6.00 min. Rain intensity = 7.50(In/Hr)
Total area = 0.170(Ac.) Total runoff = 0.420(CFS)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station 602.000 to Point/Station
603 000
**** PIPEFLOW TRAVEL TIME (User specified size) ****
Upstream point/station elevation = 450.750(Ft.)
Downstream point/station elevation = 450.500(Ft.)
Pipe length = 95.60(Ft.) Slope = 0.0026 Manning's N = 0.009 No. of pipes = 1 Required pipe flow = 0.420(CFS)
Given pipe size = 10.00(In.)
Calculated individual pipe flow = 0.420(CFS)
Normal flow depth in pipe = 3.47(In.)
Flow top width inside pipe = 9.52(In.)
Critical Depth = 3.39(In.)
Pipe flow velocity = 2.49(Ft/s)
Travel time through pipe = 0.64 min.

Time of concentration (TC) = 6.64 min.
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station 603.000 to Point/Station
603.000
**** CONFLUENCE OF MINOR STREAMS ****
Along Main Stream number: 1 in normal stream number 2
Stream flow area = 0.170(Ac.)
Runoff from this stream = 0.420(CFS)
Time of concentration = 6.64 min.

Rainfall intensity = 7.022(In/Hr)
Summary of stream data:

Stream Flow rate TC
No. (CFS) (min)
1 1.010 5.66 7.785
2 0.420 6.64 7.022
Qmax(1) =
Rainfall Intensity
(In/Hr)
08/11/2026
PH2 441 of 876

1.000

1.000
Qmax(2) =

0.902

1.000
* 1.000
* 0.852 *
* 1.000 *
* 1.000 *

1.010) +

0.420) + = 1.368

1.010) +

0.420) + = 1.331
Total of 2 streams to confluence:

Flow rates before confluence point:

1.010 0.420
Maximum flow rates at confluence using above data:

1.368 1.331
Area of streams before confluence:

0.260 0.170
Results of confluence:

Total flow rate = 1.368(CFS)
Time of concentration = 5.658 min.

Effective stream area after confluence = 0.430(Ac.)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station 603.000 to Point/Station
703.000
**** PIPEFLOW TRAVEL TIME (User specified size) ****
+++
Upstream point/station elevation = 450.500(Ft.)
Downstream point/station elevation = 450.170(Ft.)
Pipe length = 109.32(Ft.) Slope = 0.0030 Manning
No. of pipes = 1 Required pipe flow = 1.368(CFS)
Given pipe size = 10.00(In.)
Calculated individual pipe flow = 1.368(CFS)
Normal flow depth in pipe = 6.68(In.)
Flow top width inside pipe = 9.42(In.)
Critical Depth = 6.27(In.)
Pipe flow velocity = 3.53(Ft/s)
Travel time through pipe = 0.52 min.

Time of concentration (TC) = 6.17 min.
s N = 0.009
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station
703.000
**** CONFLUENCE OF MINOR STREAMS
603.000 to Point/Station
****
Along Main Stream number: 1 in normal stream number 1
Stream flow area = 0.430(Ac.)
Runoff from this stream = 1.368(CFS)
Time of concentration = 6.17 min.

Rainfall intensity = 7.359(In/Hr)
08/11/2026
PH2 442 of 876

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station
702.000
**** INITIAL AREA EVALUATION
+++
701.000 to Point/Station
* * * *
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[HIGH DENSITY RESIDENTIAL
(43.0 DU/A or Less
Impervious value, Ai = 0.800
Sub -Area C Value = 0.790
Initial subarea total flow distance = 45.000(Ft.)
Highest elevation = 465.100(Ft.)
Lowest elevation = 463.200(Ft.)
Elevation difference = 1.900(Ft.) Slope = 4.222 %
Top of Initial Area Slope adjusted by User to 4.200 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:

The maximum overland flow distance is 95.00 (Ft)
for the top area slope value of 4.20 %, in a development type of

43.0 DU/A or Less
In Accordance With Figure 3-3
Initial Area Time of Concentration = 3.37 minutes
TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)]
TC = [1.8*(1.1-0.7900)*( 95.000".5)/( 4.200^(1/3)]= 3.37 Calculated TC of 3.371 minutes is less than 5 minutes,
resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 8.431(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.790 Subarea runoff = 1.066(CFS)
Total initial stream area = 0.160(Ac.)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station
703.000
**** SUBAREA FLOW ADDITION
****
702.000 to Point/Station
Calculated TC of 3.371 minutes is less than 5 minutes,
resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 8.431(In/Hr) for a 100.0 year storm User specified 'C' value of 0.730 given for subarea
Time of concentration = 3.37 min.

Rainfall intensity = 8.431(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.742 CA = 0.579
Subarea runoff = 3.816(CFS) for 0.620(Ac.)
Total runoff = 4.882(CFS) Total area = 0.780(Ac.)
08/11/2026
PH2 443 of 876

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station 702.000 to Point/Station
703.000
**** USER DEFINED FLOW INFORMATION AT A POINT ****
User specified 'C' value of 0.740 given for subarea
Rainfall intensity (I) = 8.431(In/Hr) for a 100.0 year storm User specified values are as follows:

TC = 5.00 min. Rain intensity = 8.43(In/Hr)
Total area = 0.780(Ac.) Total runoff = 0.590(CFS)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station 703.000 to Point/Station
703.000
**** CONFLUENCE OF MINOR STREAMS ****
Along Main Stream number: 1 in normal stream number 2
Stream flow area = 0.780(Ac.)
Runoff from this stream = 0.590(CFS)
Time of concentration = 5.00 min.

Rainfall intensity = 8.431(In/Hr)
Summary of stream data:

Stream Flow rate TC Rainfall Intensity
No. (CFS) (min) (In/Hr)
1 1.368 6.17 7.359
2 0.590 5.00 8.431
Qmax(1) =

1.000 * 1.000 * 1.368) +

0.873 * 1.000 * 0.590) + = 1.883
Qmax(2) =

1.000 * 0.810 * 1.368) +

1.000 * 1.000 * 0.590) + 1.698
Total of 2 streams to confluence:

Flow rates before confluence point:

1.368 0.590
Maximum flow rates at confluence using above data:

1.883 1.698
Area of streams before confluence:

0.430 0.780
Results of confluence:

Total flow rate = 1.883(CFS)
Time of concentration = 6.174 min.

Effective stream area after confluence = 1.210(Ac.)
08/11/2026
PH2 444 of 876

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station 703.000 to Point/Station
704 000
**** PIPEFLOW TRAVEL TIME (User specified size) ****
Upstream point/station elevation = 450.170(Ft.)
Downstream point/station elevation = 450.000(Ft.)
Pipe length = 7.98(Ft.) Slope = 0.0213 Manning's N = 0.009 No. of pipes = 1 Required pipe flow = 1.883(CFS)
Given pipe size = 12.00(In.)
Calculated individual pipe flow = 1.883(CFS)
Normal flow depth in pipe = 4.10(In.)
Flow top width inside pipe = 11.38(In.)
Critical Depth = 7.02(In.)
Pipe flow velocity = 7.96(Ft/s)
Travel time through pipe = 0.02 min.

Time of concentration (TC) = 6.19 min.
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++
Process from Point/Station 801.000 to Point/Station
802.000
**** INITIAL AREA EVALUATION ****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[UNDISTURBED NATURAL TERRAIN
(Permanent Open Space )
Impervious value, Ai = 0.000
Sub -Area C Value = 0.350
Initial subarea total flow distance = 16.000(Ft.)
Highest elevation = 457.700(Ft.)
Lowest elevation = 450.500(Ft.)
Elevation difference = 7.200(Ft.) Slope 45.000 %
Top of Initial Area Slope adjusted by User to 30.000 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:

The maximum overland flow distance is 100.00 (Ft)
for the top area slope value of 30.00 %, in a development type of Permanent Open Space
In Accordance With Figure 3-3
Initial Area Time of Concentration = 4.34 minutes
TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)]
TC = [1.8*(1.1-0.3500)*( 100.000".5)/( 30.000^(1/3)]= 4.34 Calculated TC of 4.345 minutes is less than 5 minutes,
resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 8.431(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.350 08/11/2026
PH2 445 of 876

Subarea runoff = 0.091(CFS)
Total initial stream area = 0.031(Ac.)
End of computations, total study area =

3.003 (Ac.)
08/11/2026
PH2 446 of 876

APPENDIX D -

ATTENUATION/HYDRAULIC

ANALYSIS
08/11/2026
PH2 447 of 876

1 Watershed Model Schematic
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 9�- asin-1
Air - IMP -1
Legend
Hvd. Ori in Description
1 Manual Basin -1
2 Manual Basin -3
3 Reservoir IMP -3
4 Reservoir IMP -1
5 Manual Basin -5
6 Manual Basin -6
7 Manual Basin -7
8 Reservoir IMP -5
9 Reservoir IMP -4
10 Reservoir IMP -6
iiiasin-3
�- asin-5 asin-6 asin-7
liir -IMP-3 -IMP-4 -IMP-5 WI0-IMP-6
Project: 23-299-Attenuation-100yr-IMP-6-AQS-21 in Rim.gpw 08/11/2026 PH2
Tuesday, 03 / 11 / 2025
448 of 876

2 Hydrograph Return Period Recall
draflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Hyd.

No.

Hydrograph
type
(origin)
Inflow
hyd(s)
Peak Outflow (cfs)
Hydrograph
Description
1-yr
2-yr
3-yr
5-yr
10-yr
25-yr
50-yr
100-yr
1 Manual

0.540
Basin -1
2 Manual

0.570
Basin -3
3 Reservoir
2 0.364
IMP -3
4 Reservoir
1 0.367
IMP -1
5 Manual

1.790
Basin -5
6 Manual
------

0.730
Basin -6
7 Manual

4.880
Basin -7
8 Reservoir
6 0.418
IMP -5
9 Reservoir
5 ------
------

1.007
IMP -4
10 Reservoir
7 0.593
IMP -6
Proj. file: 23-299-Attenuation-100yr-IMP-6-AQS-21 in Rim.gpw Tuesday, 03 / 11 / 2025
08/11/2026 PH2
449 of 876

3 Hydrograph Summary Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Hyd.

No.

Hydrograph
type
(origin)
Peak
flow
(cfs)
Time
interval
(min)
Time to
Peak
(min)
Hyd.
volume
(cuft)
Inflow
hyd(s)
Maximum
elevation
(ft)
Total
strge used
(cuft)
Hydrograph
Description
1 Manual

0.540
5 245
750
Basin -1
2 Manual

0.570
6 246
853
Basin -3
3 Reservoir

0.364
6 246
853
2 461.53
315
IMP -3
4 Reservoir

0.367
5 245
749
1 463.54
196
IMP -1
5 Manual

1.790
5 245
2,433
-----
Basin -5
6 Manual

0.730
6 246
1,084
-----
-----
Basin -6
7 Manual

4.880
5 245
6,594
Basin -7
8 Reservoir

0.418
6 252
1,083
6 456.63
264
IMP -5
9 Reservoir

1.007
5 250
2,432
5 459.60
548
IMP -4
10 Reservoir

0.593
5 255
6,554
7 456.04
4,834
IMP -6
23-299-Attenuation-100yr-IMP-6-AQS-21in RirROluin
Period: 100 Year
Tuesday, 03 / 11 / 2025
08/11/2026
PH2
450 of 876

Time(min) Q(cfs)
0 0
5 0.01
10 0.01
15 0.01
20 0.01
25 0.01
30 0.01
35 0.01
40 0.01
45 0.01
50 0.01
55 0.01
60 0.01
65 0.02
70 0.02
75 0.02
80 0.02
85 0.02
90 0.02
95 0.02
100 0.02
105 0.02
110 0.02
115 0.02
120 0.02
125 0.02
130 0.02
135 0.02
140 0.02
145 0.02
150 0.02
155 0.02
160 0.02
165 0.03
170 0.03
175 0.03
180 0.03
185 0.03
190 0.03
195 0.04
200 0.04
205 0.04
210 0.04
BASIN -1:

TIME OF CONCENTRATION = 5 MIN.
6 HOUR RAINFALL = 3.2 INCHES
BASIN AREA = 0.14 ACRES
RUNOFF COEFFICIENT = 0.47
PEAK DISCHARGE = 0.54 CFS
08/11/2026
PH2 451 of 876

215 0.05
220 0.05
225 0.07
230 0.07
235 0.11
240 0.15
245 0.54
250 0.09
255 0.06
260 0.05
265 0.04
270 0.03
275 0.03
280 0.03
285 0.03
290 0.02
295 0.02
300 0.02
305 0.02
310 0.02
315 0.02
320 0.02
325 0.02
330 0.02
335 0.01
340 0.01
345 0.01
350 0.01
355 0.01
360 0.01
08/11/2026
PH2 452 of 876

4 Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Tuesday, 03 / 11 / 2025 Hyd. No. 1
Basin -1
Hydrograph type
Storm frequency
Time interval
= Manual
= 100 yrs
= 5 min
Peak discharge
Time to peak
Hyd. volume
= 0.540 cfs
= 4.08 hrs
= 750 cuft
Q (cfs)

1.00 _

0.90 0.80

0.70 0.60

0.50 0.40

0.30 0.20

0.10 0.00
Basin -1
Hyd. No. 1 -- 100 Year

0.0 1.0 2.0
Hyd No. 1
Q (cfs)

1.00 0.90

0.80 0.70

0.60 0.50

0.40 0.30

0.20 0.10

0.00 3.0 4.0 5.0 6.0 7.0
Time (hrs)
08/11/2026
PH2 453 of 876

8 Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Tuesday, 03 / 11 / 2025 Hyd. No. 4
IMP -1
Hydrograph type
Storm frequency
Time interval
Inflow hyd. No.

Reservoir name
= Reservoir
= 100 yrs
= 5 min
= 1 - Basin -1
= IMP -1
Peak discharge
Time to peak
Hyd. volume
Max. Elevation
Max. Storage
= 0.367 cfs
= 4.08 hrs
= 749 cuft
= 463.54 ft
= 196 tuft
Storage Indication method used.

Q (cfs)

1.00 _

0.90 0.80

0.70 0.60

0.50 0.40

0.30 0.20

0.10 0.00
IMP -1
Hyd. No. 4 -- 100 Year
Il 1 1 1 1 1 f l l
V

0.0 1.0 2.0 3.0 4.0 5.0 6.0
Hyd No. 4
Hyd No. 1 I Total storage used = 196 cuft
Q (cfs)

1.00 0.90

0.80 0.70

0.60 0.50

0.40 0.30

0.20 0.10

0.00 7.0
Time (hrs)
08/11/2026
PH2 454 of 876

Pond Report
9 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Pond No. 5 - IMP -1
Pond Data
Contours -User-defined contour areas. Average end area method used for volume calculation. Begining Elevation = 459.25 ft Stage / Storage Table
Stage (ft)
Elevation (ft) Contour area (sqft)

0.00 459.25 01

1.25 460.50 01

1.25 460.50 UNDERGROUND 01

3.25 462.50 01

3.25 462.50 SURFACE 121

4.25 463.50 239

5.00 464.25 345
Incr. Storage (cuft) Total storage (cuft)
140% VOID
100% VOID
0 1
0 2
0 180
219
0 1
1 3
3 183
402
Tuesday, 03 / 11 / 2025
Culvert / Orifice Structures Weir Structures
[A] [B] [C] [PrfRsr]
[A] [B] [C] [D]
Rise (in) = 6.00 0.25 0.00 0.00 Crest Len (ft) = 1.50 0.00 0.00 0.00 Span (in) = 6.00 0.25 0.00 0.00 Crest EI. (ft) = 463.33 0.00 0.00 0.00 N6. Barrels = 1 1 0 Weir Coeff. = 3.33 3.33 3.33 3.33
Invert EI. (ft) = 459.25 459.50 0.00 0.00 Weir Type = 1 Length (ft) = 45.61 0.00 0.00 0.00 Multi -Stage = Yes No No No Slope (%) = 0.50 0.00 0.00 n/a
N -Value = .013 .013 .013 n/a
Orifice Coeff. = 0.60 0.60 0.60 0.60 Exfil.(in/hr) = 0.000 (by Wet area) Multi -Stage = n/a Yes No No TW Elev. (ft) = 0.00
Stage (ft)

5.00 _

4.00 3.00

2.00 1.00

0.00 Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s).

Stage / Discharge

0.00 0.08 0.16 0.24
Total Q Culv A
Struct HG WeirA

0.32 Culv B
Elev (ft)
464.25
463.25
462.25
461.25
460.25
459.25

0.40 0.48 0.56 0.64 0.72 0.80
Discharge (cfs)
08/11/2026
PH2 455 of 876

Pond N o. 5 - IMP -1
Hydraflow Hydrographs Extension for Autodesk ® Civil 3D ® by Autodesk, Inc . v2023 9Z0Z/ L- L-/80
-o
2 O1
O
Co
Q)
- 6.00
- 5.00
- 4.00
- 3.00
- 2.00
- 1. 00
- 0. 00
Stage (ft)
Top of pond
Elev . 464 .25

1.50 ft Riser
WeirA - Elev. 463 .33
45 .6 LF of 6.0 in @ 0.50%
CulvA - Inv. 459.25

0.25 in orifice
CulvB - Inv. 459.50
IX'//'' / \\\.\\� \.� \ Bottom of pond
Front View Elev. 459.25
NTS - Looking Downstream
100-yr
Inflow hydrograph = 1. Manual - Basin -1
Project: 23-299-Attenuation-100yr-IMP-6-AQS-21 in Rim.gpw Tuesday, 03 / 11 / 2025

Time(min) Q(cfs)
0 0
6 0.01
12 0.01
18 0.01
24 0.01
30 0.01
36 0.02
42 0.02
48 0.02
54 0.02
60 0.02
66 0.02
72 0.02
78 0.02
84 0.02
90 0.02
96 0.02
102 0.02
108 0.02
114 0.02
120 0.02
126 0.02
132 0.02
138 0.02
144 0.02
150 0.03
156 0.03
162 0.03
168 0.03
174 0.03
180 0.03
186 0.03
192 0.04
198 0.04
204 0.04
210 0.05
216 0.05
222 0.06
228 0.07
234 0.11
240 0.15
246 0.57
252 0.09
BASIN -3:

TIME OF CONCENTRATION = 6 MIN.
6 HOUR RAINFALL = 3.2 INCHES
BASIN AREA = 0.11 ACRES
RUNOFF COEFFICIENT = 0.66
PEAK DISCHARGE = 0.57 CFS
08/11/2026
PH2 457 of 876

258 0.06
264 0.05
270 0.04
276 0.03
282 0.03
288 0.03
294 0.02
300 0.02
306 0.02
312 0.02
318 0.02
324 0.02
330 0.02
336 0.02
342 0.02
348 0.02
354 0.01
360 0.01
08/11/2026
PH2 458 of 876

5 Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Tuesday, 03 / 11 / 2025 Hyd. No. 2
Basin -3
Hydrograph type
Storm frequency
Time interval
= Manual
= 100 yrs
= 6 min
Peak discharge
Time to peak
Hyd. volume
= 0.570 cfs
= 4.10 hrs
= 853 cuft
Q (cfs)

1.00 _

0.90 0.80

0.70 0.60

0.50 0.40

0.30 0.20

0.10 0.00
Basin -3
Hyd. No. 2 -- 100 Year

0.0 1.0 2.0
Hyd No. 2
Q (cfs)

1.00 0.90

0.80 0.70

0.60 0.50

0.40 0.30

0.20 0.10

0.00 3.0 4.0 5.0 6.0 7.0
Time (hrs)
08/11/2026
PH2 459 of 876

6 Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Tuesday, 03 / 11 / 2025 Hyd. No. 3
IMP -3
Hydrograph type
Storm frequency
Time interval
Inflow hyd. No.

Reservoir name
= Reservoir
= 100 yrs
= 6 min
= 2 - Basin -3
= IMP -3
Peak discharge
Time to peak
Hyd. volume
Max. Elevation
Max. Storage
= 0.364 cfs
= 4.10 hrs
= 853 cuft
= 461.53 ft
= 315 cuft
Storage Indication method used.

Q (cfs)

1.00 0.90

0.80 0.70

0.60 0.50

0.40 0.30

0.20 0.10

0.00 IMP -3
Hyd. No. 3 -- 100 Year

1.0 2.0

3.0 4.0

5.0 6.0

0.0 Hyd No. 3
r l r -I 1 1 1 1 1
Hyd No. 2
I Total storage used = 315 cuft
Q (cfs)

1.00 0.90

0.80 0.70

0.60 0.50

0.40 0.30

0.20 0.10

0.00 7.0
Time (hrs)
08/11/2026
PH2
460 of 876

Pond Report
7 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Pond No. 2 - IMP -3
Pond Data
Contours -User-defined contour areas. Average end area method used for volume calculation. Begining Elevation = 457.25 ft Stage / Storage Table
Stage (ft)
Elevation (ft) Contour area (sqft)
Incr. Storage (cuft) Total storage (cuft)

0.00 457.25 01 0

1.25 458.50 01 1

1.25 458.50 UNDERGROUND 01 40% VOID 0

3.25 460.50 01 2

3.25 460.50 218 0

4.25 461.50 SURFACE 377 100% VOID 297

5.00 462.25 512 333
0 1
1 3
3 301
634
Tuesday, 03 / 11 / 2025
Culvert / Orifice Structures Weir Structures
[A] [B] [C] [PrfRsr]
[A] [B] [C] [D]
Rise (in) = 8.00 0.25 0.00 0.00 Crest Len (ft) = 1.50 0.00 0.00 0.00 Span (in) = 8.00 0.25 0.00 0.00 Crest EI. (ft) = 461.33 0.00 0.00 0.00 N6. Barrels = 1 0 0 Weir Coeff. = 3.33 3.33 3.33 3.33
Invert EI. (ft) = 457.25 457.50 0.00 0.00 Weir Type = 1 Length (ft) = 22.40 0.00 0.00 0.00 Multi -Stage = Yes No No No Slope (%) = 0.50 0.00 0.00 n/a
N -Value = .013 .013 .013 n/a
Orifice Coeff. = 0.60 0.60 0.60 0.60 Exfil.(in/hr) = 0.000 (by Wet area) Multi -Stage = n/a Yes No No TW Elev. (ft) = 0.00
Stage (ft)

5.00 _

4.00 3.00

2.00 1.00

0.00 Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s).

Stage / Discharge

0.00 0.08 0.16 0.24
Total Q Culv A
Struct HG WeirA

0.32 Culv B
Elev (ft)
462.25
461.25
460.25
459.25
458.25
457.25

0.40 0.48 0.56 0.64 0.72 0.80
Discharge (cfs)
08/11/2026
PH2 461 of 876

Pond N o. 2 - IMP -3
Hydraflow Hydrographs Extension for Autodesk ® Civil 3D ® by Autodesk, Inc . v2023 9Z0Z/ L- L-/80
-o
2 - 6.00
- 5.00
- 4.00
- 3.00
- 2.00
- 1. 00
- 0. 00
Stage (ft)
Top of pond
Elev . 462 .25

1.50 ft Riser
WeirA - Elev. 461 .33
•

22.4 LF of 8.0 in @ 0.50%
CulvA - Inv. 457 .25

0.25 in orifice
CulvB - Inv. 457.50
IX'//'' / \\\.\\� \.� \ Bottom of pond
Front View Elev. 457.25
NTS - Looking Downstream
100-yr
Inflow hydrograph = 2. Manual - Basin -3
Project: 23-299-Attenuation-100yr-IMP-6-AQS-21 in Rim.gpw Tuesday, 03 / 11 / 2025

Time(min) Q(cfs)
0 0
5 0.04
10 0.04
15 0.04
20 0.04
25 0.04
30 0.04
35 0.04
40 0.04
45 0.05
50 0.05
55 0.05
60 0.05
65 0.05
70 0.05
75 0.05
80 0.05
85 0.05
90 0.05
95 0.05
100 0.06
105 0.06
110 0.06
115 0.06
120 0.06
125 0.06
130 0.06
135 0.07
140 0.07
145 0.07
150 0.07
155 0.08
160 0.08
165 0.08
170 0.08
175 0.09
180 0.09
185 0.1
190 0.1
195 0.11
200 0.12
205 0.13
210 0.14
BASIN -5:

TIME OF CONCENTRATION = 5 MIN.
6 HOUR RAINFALL = 3.2 INCHES
BASIN AREA = 0.26 ACRES
RUNOFF COEFFICIENT = 0.81
PEAK DISCHARGE = 1.79 CFS
08/11/2026
PH2 463 of 876

215 0.16
220 0.17
225 0.21
230 0.24
235 0.35
240 0.5
245 1.79
250 0.28
255 0.19
260 0.15
265 0.12
270 0.11
275 0.1
280 0.09
285 0.08
290 0.07
295 0.07
300 0.07
305 0.06
310 0.06
315 0.06
320 0.05
325 0.05
330 0.05
335 0.05
340 0.05
345 0.04
350 0.04
355 0.04
360 0.04
08/11/2026
PH2 464 of 876

10 Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Tuesday, 03 / 11 / 2025 Hyd. No. 5
Basin -5
Hydrograph type
Storm frequency
Time interval
= Manual
= 100 yrs
= 5 min
Peak discharge
Time to peak
Hyd. volume
= 1.790 cfs
= 4.08 hrs
= 2,433 cuft
Basin -5
Q (cfs) Hyd. No. 5 -- 100 Year Q (cfs)

2.00 1.00

0.00 2.0

3.0 4.0

5.0 0.0

1.0 Hyd No. 5

6.0 2.00

1.00 0.00

7.0 Time (hrs)
08/11/2026
PH2
465 of 876

15 Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Tuesday, 03 / 11 / 2025 Hyd. No. 9
IMP -4
Hydrograph type
Storm frequency
Time interval
Inflow hyd. No.

Reservoir name
= Reservoir
= 100 yrs
= 5 min
= 5 - Basin -5
= IMP -4
Peak discharge
Time to peak
Hyd. volume
Max. Elevation
Max. Storage
= 1.007 cfs
= 4.17 hrs
= 2,432 cuft
= 459.60 ft
= 548 cuft
Storage Indication method used.

IMP -4
Q (cfs) Hyd. No. 9 -- 100 Year Q (cfs)

2.00 1.00

0.00 0.0 1.0 2.0 3.0 4.0 5.0 6.0
Hyd No. 9
Hyd No. 5 I Total storage used = 548 cuft

2.00 1.00

0.00 7.0
Time (hrs)
08/11/2026
PH2 466 of 876

Pond Report
16 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Pond No. 3 - IMP -4
Pond Data
Contours -User-defined contour areas. Average end area method used for volume calculation. Begining Elevation = 455.25 ft Stage / Storage Table
Stage (ft)
Elevation (ft) Contour area (sqft)
Incr. Storage (cuft) Total storage (cuft)

0.00 455.25 01 0

1.25 456.50 01 40% VOID 1

1.25 456.50 UNDERGROUND 01 o

3.25 458.50 01 2

3.25 458.50 318 0

4.25 459.50 SURFACE 500 100% VOID 409

4.75 460.00 600 275

5.00 460.25 654 157
0 1
1 3
3 412
687
844
Tuesday, 03 / 11 / 2025
Culvert / Orifice Structures Weir Structures
[A] [B] [C] [PrfRsr]
[A] [B] [C] [D]
Rise (in) = 10.00 0.26 0.00 0.00 Crest Len (ft) = 2.15 0.00 0.00 0.00 Span (in) = 10.00 0.26 0.00 0.00 Crest EI. (ft) = 459.33 0.00 0.00 0.00 N6. Barrels = 1 0 0 Weir Coeff. = 3.33 3.33 3.33 3.33
Invert EI. (ft) = 455.25 455.50 0.00 0.00 Weir Type = 1 --- --- --- Length (ft) = 77.07 0.00 0.00 0.00 Multi -Stage = Yes No No No Slope (%) = 0.30 0.00 0.00 n/a
N -Value = .013 .013 .013 n/a
Orifice Coeff. = 0.60 0.60 0.60 0.60 Exfil.(in/hr) = 0.000 (by Wet area) Multi -Stage = n/a Yes No No TW Elev. (ft) = 0.00
Note: CulverUOrifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s).

Stage (ft) Stage / Discharge

5.00 4.00

3.00 2.00

1.00 0.00

0.00 0.50 1.00 1.50
Total Q Culv A
Struct HG Weir A
Culv B
Elev (ft)
460.25
459.25
458.25
457.25
456.25
455.25

2.00 Discharge (cfs)
08/11/2026
PH2 467 of 876

Pond N o. 3 - IMP -4
Hydraflow Hydrographs Extension for Autodesk ® Civil 3D ® by Autodesk, Inc . v2023 9Z0Z/ L- L-/80
a,
Oo
O
Co
a)
- 6.00
- 5.00
- 4.00
- 3.00
- 2.00
- 1. 00
- 0. 00
Stage (ft)
Top of pond
Elev . 460 .25
WeirA - Elev . 459.33
\ •
77 .1 LF of 10.0 in @ 0.30%
CulvA - Inv. 455.25
.26 in orific e
ulvB - Inv. 455.50
Bottom of pond
Front View Elev. 455.25
NTS - Looking Downstream
100-yr
Inflow hydrograph = 5. Manual - Basin -5
Project: 23-299-Attenuation-100yr-IMP-6-AQS-21 in Rim.gpw Tuesday, 03 / 11 / 2025

Time(min) Q(cfs)
0 0
6 0.02
12 0.02
18 0.02
24 0.02
30 0.02
36 0.02
42 0.02
48 0.02
54 0.02
60 0.02
66 0.02
72 0.02
78 0.02
84 0.02
90 0.02
96 0.02
102 0.02
108 0.03
114 0.03
120 0.03
126 0.03
132 0.03
138 0.03
144 0.03
150 0.03
156 0.03
162 0.04
168 0.04
174 0.04
180 0.04
186 0.04
192 0.05
198 0.05
204 0.05
210 0.06
216 0.07
222 0.08
228 0.09
234 0.14
240 0.2
246 0.73
252 0.11
BASIN -6:

TIME OF CONCENTRATION = 6 MIN.
6 HOUR RAINFALL = 3.2 INCHES
BASIN AREA = 0.17 ACRES
RUNOFF COEFFICIENT = 0.55
PEAK DISCHARGE = 0.73 CFS
08/11/2026
PH2 469 of 876

258 0.07
264 0.06
270 0.05
276 0.04
282 0.04
288 0.03
294 0.03
300 0.03
306 0.03
312 0.03
318 0.02
324 0.02
330 0.02
336 0.02
342 0.02
348 0.02
354 0.02
360 0.02
08/11/2026
PH2 470 of 876

11 Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Tuesday, 03 / 11 / 2025 Hyd. No. 6
Basin -6
Hydrograph type
Storm frequency
Time interval
= Manual
= 100 yrs
= 6 min
Peak discharge
Time to peak
Hyd. volume
= 0.730 cfs
= 4.10 hrs
= 1,084 cuft
Q (cfs)

1.00 _

0.90 0.80

0.70 0.60

0.50 0.40

0.30 0.20

0.10 0.00
Basin -6
Hyd. No. 6 -- 100 Year

0.0 1.0 2.0
Hyd No. 6
Q (cfs)

1.00 0.90

0.80 0.70

0.60 0.50

0.40 0.30

0.20 0.10

0.00 3.0 4.0 5.0 6.0 7.0
Time (hrs)
08/11/2026
PH2 471 of 876

13 Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Tuesday, 03 / 11 / 2025 Hyd. No. 8
IMP -5
Hydrograph type
Storm frequency
Time interval
Inflow hyd. No.

Reservoir name
= Reservoir
= 100 yrs
= 6 min
= 6 - Basin -6
= IMP -5
Peak discharge
Time to peak
Hyd. volume
Max. Elevation
Max. Storage
= 0.418 cfs
= 4.20 hrs
= 1,083 cuft
= 456.63 ft
= 264 cuft
Storage Indication method used.

Q (cfs)

1.00 _

0.90 0.80

0.70 0.60

0.50 0.40

0.30 0.20

0.10 IMP -5
Hyd. No. 8 -- 100 Year

0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0
Hyd No. 8
Hyd No. 6 I Total storage used = 264 cuft
Q (cfs)

1.00 0.90

0.80 0.70

0.60 0.50

0.40 0.30

0.20 0.10

0.00 Time (hrs)
08/11/2026
PH2 472 of 876

Pond Report
14 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Pond No. 4 - IMP -5
Pond Data
Contours -User-defined contour areas. Average end area method used for volume calculation. Begining Elevation = 452.25 ft Stage / Storage Table
Stage (ft)
Elevation (ft) Contour area (sqft)

0.00 452.25 01

1.25 453.50 UNDERGROUND 01

1.25 453.50 01

3.25 455.50 01

3.25 455.50 141

4.25 456.50 SURFACE 288

5.00 457.25 414
Incr. Storage (cuft) Total storage (cuft)
40% VOID
100% VOID
0 1
0 2
0 214
263
0 1
1 3
3 218
481
Tuesday, 03 / 11 / 2025
Culvert / Orifice Structures Weir Structures
[A] [B] [C] [PrfRsr]
[A] [B] [C] [D]
Rise (in) = 10.00 0.25 0.00 0.00 Crest Len (ft) = 1.50 0.00 0.00 0.00 Span (in) = 10.00 0.25 0.00 0.00 Crest EI. (ft) = 456.33 0.00 0.00 0.00 N6. Barrels = 1 0 0 Weir Coeff. = 3.33 3.33 3.33 3.33
Invert EI. (ft) = 450.75 451.00 0.00 0.00 Weir Type = 1 Length (ft) = 204.96 0.00 0.00 0.00 Multi -Stage = Yes No No No Slope (%) = 0.30 0.00 0.00 n/a
N -Value = .013 .013 .013 n/a
Orifice Coeff. = 0.60 0.60 0.60 0.60 Exfil.(in/hr) = 0.000 (by Wet area) Multi -Stage = n/a Yes No No TW Elev. (ft) = 0.00
Stage (ft)

5.00 4.00

3.00 2.00

1.00 0.00

0.08 0.16

0.24 0.32

0.40 0.48

0.56 0.64

0.72 0.00
Total Q
Struct HG
Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s).

Culv A
WeirA
Stage / Discharge
Culv B
Elev (ft)
457.25
456.25
455.25
454.25
453.25
452.25

0.80 Discharge (cfs)
08/11/2026
PH2
473 of 876

Pond N o. 4 - IMP -5
Hydraflow Hydrographs Extension for Autodesk ® Civil 3D ® by Autodesk, Inc . v2023 9Z0Z/ L- L-/80
O
Co
Q)
- 6.00
- 5. 00
- 4. 00
- 3. 00
- 2.00
- 1. 00
- 0.00
Stage (ft)
Top of p ond
Elev . 457 .25

1.50 ft Riser
cu
205.0 LF of 10.0 in @ 0.30%
CulvA - Inv . 450.75

0.25 in orifice
CulvB - Inv . 451.00
Bottom of pond
El ev. 452.25
Front View
NTS - Looking Downstream
100-yr
Inflow hydrograph = 6. Manual - Basin -6
Project: 23-299-Attenuation-100yr-IMP-6-AQS-21 in Rim.gpw Tuesday, 03 / 11 / 2025

Time(hr) Q(cfs)
0 0
5 0.11
10 0.11
15 0.11
20 0.11
25 0.11
30 0.12
35 0.12
40 0.12
45 0.12
50 0.12
55 0.13
60 0.13
65 0.13
70 0.13
75 0.14
80 0.14
85 0.14
90 0.14
95 0.15
100 0.15
105 0.15
110 0.16
115 0.16
120 0.16
125 0.17
130 0.17
135 0.18
140 0.18
145 0.19
150 0.2
155 0.21
160 0.21
165 0.22
170 0.23
175 0.24
180 0.25
185 0.27
190 0.28
195 0.3
200 0.32
205 0.35
210 0.37
BASIN -7:

TIME OF CONCENTRATION = 5 MIN.
6 HOUR RAINFALL = 3.2 INCHES
BASIN AREA = 0.78 ACRES
RUNOFF COEFFICIENT = 0.73
PEAK DISCHARGE = 4.88 CFS
08/11/2026
PH2 475 of 876

215 0.43
220 0.47
225 0.57
230 0.65
235 0.95
240 1.34
245 4.88
250 0.76
255 0.51
260 0.4
265 0.33
270 0.29
275 0.26
280 0.24
285 0.22
290 0.2
295 0.19
300 0.18
305 0.17
310 0.16
315 0.15
320 0.15
325 0.14
330 0.13
335 0.13
340 0.12
345 0.12
350 0.12
355 0.11
360 0.11
08/11/2026
PH2 476 of 876

12 Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Tuesday, 03 / 11 / 2025 Hyd. No. 7
Basin -7
Hydrograph type
Storm frequency
Time interval
= Manual
= 100 yrs
= 5 min
Peak discharge
Time to peak
Hyd. volume
= 4.880 cfs
= 4.08 hrs
= 6,594 cuft
Basin -7
Q (cfs) Hyd. No. 7 -- 100 Year Q (cfs)

5.00 4.00

3.00 2.00

1.00 0.00

0.0 1.0 2.0 3.0 4.0 5.0 6.0
Hyd No. 7

5.00 4.00

3.00 2.00

1.00 0.00

7.0 Time (hrs)
08/11/2026
PH2 477 of 876

17 Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Tuesday, 03 / 11 / 2025 Hyd. No. 10
IMP -6
Hydrograph type
Storm frequency
Time interval
Inflow hyd. No.

Reservoir name
= Reservoir
= 100 yrs
= 5 min
= 7 - Basin -7
= IMP -6
Peak discharge
Time to peak
Hyd. volume
Max. Elevation
Max. Storage
= 0.593 cfs
= 4.25 hrs
= 6,554 cuft
= 456.04 ft
= 4,834 cuft
Storage Indication method used.

IMP -6
Q (cfs) Q (cfs)
Hyd. No. 10 -- 100 Year

5.00 4.00

3.00 2.00

1.00 0.00
0 5

5.00 4.00

3.00 2.00

1.00 0.00
10 15 20 25 30 35 40 45 50 55 60 65
Time (hrs)
Hyd No. 10
Hyd No. 7 I Total storage used = 4,834 cuft
08/11/2026
PH2 478 of 876

Pond Report
18 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Pond No. 1 - IMP -6
Pond Data
Contours -User-defined contour areas. Average end area method used for volume calculation. Begining Elevation = 450.25 ft Stage / Storage Table
Stage (ft) Elevation (ft)
Contour area (sqft)
Incr. Storage (cuft) Total storage (cuft)

0.00 450.25 1,260

2.50 452.75

2.50 2.75

2.75 4.75

4.75 5.75

6.50 90% VOID

1.260 3.150
0 45215
452.05 UNDERGROUND (31 90% VOID
453.00 UNDERGROUND 01 40% VOID
455.00 01
455.00 1,400
456.00 SURFACE 1,821
456.75 2,160
100% VOID
f)
0 2
1 1,609
1,493
0 3.150
3,151
3 151
3,151
3,153
3,154
4,762
6,255
Tuesday, 03 / 11 / 2025

THIS DEPTH IS COUNTED FOR THE
100-YR STORAGE
Culvert / Orifice Structures Weir Structures
[A] [B] [C] [PrfRsr]
[A] [B] [C] [D]
Rise (in) = 12.00 0.80 3.00 0.00 Crest Len (ft) = 1.50 0.00 0.00 0.00 Span (in) = 12.00 0.80 3.00 0.00 Crest EI. (ft) = 455.83 0.00 0.00 0.00 N6. Barrels = 1 1 0 Weir Coeff. = 3.33 3.33 3.33 3.33
Invert EI. (ft) = 450.17 450.25 455.25 0.00 Weir Type = 1 --- --- --- Length (ft) = 7.98 0.00 0.00 0.00 Multi -Stage = Yes No No No Slope (%) = 2.00 0.00 0.00 n/a
N -Value = .013 .013 .013 n/a
Orifice Coeff. = 0.60 0.60 0.60 0.60 Exfil.(in/hr) = 0.000 (by Wet area) Multi -Stage = n/a Yes Yes No TW Elev. (ft) = 0.00
Stage (ft)

7.00 _

6.00 5.00

4.00 3.00

2.00 1.00

0.00 Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s).

Stage / Discharge

0.00 0.50 1.00 1.50
Total Q CuIv A
Struct HG Weir A
Cult' B Cult' C
Elev (ft)
457.25
456.25
455.25
454.25
453.25
452.25
451.25
450.25

2.00 Discharge (cfs)
08/11/2026
PH2 479 of 876

Pond N o. 1 - IMP -6
Hydraflow Hydrographs Extension for Autodesk ® Civil 3D ® by Autodesk, Inc . v2023 9Z0Z/ I L-/80
CO
0 Co
O
- 7.00
- 6. 00
- 5.00
- 4.00
- 3. 00
- 2.00
- 1.00
- 0.00
Stage (ft)

3.00 in orifice
A CS 9G
Top of pond
Elev. 456 .75

1.50 ft Riser
W eirA - Fl ev 455 83
2 8.0 LF of 12.0 in @ 2.00 %
CulvA - Inv. 450.17

0.80 in orifice
CulvB - Inv. 450.25
Bottom of pond
Elev . 450 .25
Front View
NTS - Looking Downstream
100-yr
Inflow hydrograph = 7. Manual - Basin -7
Project: 23-299-Attenuation-100yr-IMP-6-AQS-21 in Rim.gpw Tuesday, 03 / 11 / 2025

Channel Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc. Wednesday, Mar 12 2025 Basin -1
Circular
Diameter (ft)
Invert Elev (ft)
Slope (%)
N -Value
Calculations
Compute by:

Known Q (cfs)
Elev (ft)
460.00
459.75
459.50
459.25
459.00
= 0.50
= 459.25
= 0.50
= 0.009
Known Q
= 0.37
Highlighted
Depth (ft)
Q (cfs)
Area (sqft)
Velocity (ft/s)
Wetted Perim (ft)
Crit Depth, Yc (ft)
Top Width (ft)
EGL (ft)
= 0.30
= 0.370
= 0.12
= 3.00
= 0.89
= 0.31
= 0.49
= 0.44
0 1
08/11/2026
PH2
481 of 876

Channel Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc. Wednesday, Mar 12 2025 Basin -3
Circular
Diameter (ft)
Invert Elev (ft)
Slope (%)
N -Value
Calculations
Compute by:

Known Q (cfs)
Elev (ft)
458.00
457.75
457.50
457.25
457.00
= 0.50
= 457.25
= 0.50
= 0.009
Known Q
= 0.36
Highlighted
Depth (ft)
Q (cfs)
Area (sqft)
Velocity (ft/s)
Wetted Perim (ft)
Crit Depth, Yc (ft)
Top Width (ft)
EGL (ft)
= 0.29
= 0.360
= 0.12
= 3.04
= 0.87
= 0.31
= 0.49
= 0.43
0 1
08/11/2026
PH2 482 of 876

Channel Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc. Wednesday, Mar 12 2025 Basin -5
Circular
Diameter (ft)
Invert Elev (ft)
Slope (%)
N -Value
Calculations
Compute by:

Known Q (cfs)
Elev (ft)
457.00
456.50
456.00
455.50
455.00
454.50
= 0.83
= 455.25
= 0.30
= 0.009
Known Q
= 1.01
Highlighted
Depth (ft)
Q (cfs)
Area (sqft)
Velocity (ft/s)
Wetted Perim (ft)
Crit Depth, Yc (ft)
Top Width (ft)
EGL (ft)
Section
= 0.46
= 1.010
= 0.31
= 3.28
= 1.39
= 0.45
= 0.83
= 0.63
0 1
3 Depth (ft)

1.75 1.25

0.75 0.25
- 0.25
- 0.75
08/11/2026
PHReach (ft)
483 of 876

Channel Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc. Wednesday, Mar 12 2025 Basins 5+6
Circular
Diameter (ft)
Invert Elev (ft)
Slope (%)
N -Value
Calculations
Compute by:

Known Q (cfs)
Elev (ft)
452.00
451.50
451.00
450.50
450.00
= 0.83
= 450.50
= 0.30
= 0.009
Known Q
= 1.60
Highlighted
Depth (ft)
Q (cfs)
Area (sqft)
Velocity (ft/s)
Wetted Perim (ft)
Crit Depth, Yc (ft)
Top Width (ft)
EGL (ft)
Section
= 0.64
= 1.600
= 0.45
= 3.57
= 1.78
= 0.57
= 0.70
= 0.84
0 1 2
08/11/2026
PH2 Reach (ft) 484 of 876

Channel Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc. Wednesday, Mar 12 2025 Basins 5+6+7
Circular
Diameter (ft)
Invert Elev (ft)
Slope (%)
N -Value
Calculations
Compute by:

Known Q (cfs)
Elev (ft)
452.00
451.50
451.00
450.50
450.00
449.50
= 1.00
= 450.17
= 2.00
= 0.009
Known Q
= 2.02
Highlighted
Depth (ft)
Q (cfs)
Area (sqft)
Velocity (ft/s)
Wetted Perim (ft)
Crit Depth, Yc (ft)
Top Width (ft)
EGL (ft)
Section
= 0.36
= 2.020
= 0.26
= 7.89
= 1.29
= 0.61
= 0.96
= 1.33
0 1 2 3
Depth (ft)

1.83 1.33

0.83 0.33
- 0.17
- 0.67
08/11/2026
PHReach (ft) 485 of 876

Channel Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc. Wednesday, Mar 12 2025 Basin -6
Circular
Diameter (ft)
Invert Elev (ft)
Slope (%)
N -Value
Calculations
Compute by:

Known Q (cfs)
Elev (ft)
452.00
451.50
451.00
450.50
450.00
= 0.67
= 450.75
= 0.30
= 0.009
Known Q
= 0.42
Highlighted
Depth (ft)
Q (cfs)
Area (sqft)
Velocity (ft/s)
Wetted Perim (ft)
Crit Depth, Yc (ft)
Top Width (ft)
EGL (ft)
Section
= 0.31
= 0.420
= 0.16
= 2.62
= 1.00
= 0.31
= 0.67
= 0.42
0 1 2
08/11/2026
PH2 Reach (ft) 486 of 876

EXHIBITS
08/11/2026
PH2 487 of 876

9Z0Z/L- L-/80
2 fV
600
O100= 2.20
Tc = 7.74
I I = 0.99
OD
OD
0 03

W BOBIER DRIVE
100
0100= 0 .10
Tc = 5.00
BASIN -1 = 0.034 @

0.034 AC '
gm -
1 �I / I
r ,,r
`\
1 1 rJ ! iil'IL /
1 i ;. \ .,', -7-72- :(, 1 \
1 1, II ,, \, �\I �,I_z- --__ / I
\, `\ I\ ,, 1\ \I ,�\\` N
\
, '\ I \\ \\ 1t. \ \\\ \\
v, I '1 i 1
1 ,1 tl \ ,
1 1
I'I
, 1
I,
, fI
I, ,
`I `\ '',, ,J2••• •• II
A.y `... -,... .,.. .. 1i III_ ,',
\
1 POC-2
I FOR BASIN -600.
1 1
1 I
I
I
I
asa
•519=
lome
®
200
Q100= 0 .16
Tc = 5.06
= 0 .056
insi
,BASIN -3
0,13 AC
•
`
BASIN -5
0,27 AC
300
Q100= 0.33
Tc = 6.34
= 0 .13
400
0100= 0.49
Tc = 6.22
= 0.19
500
0100= 0.67
Tc = 6.55
= 0.27
__7
LEGEND
100
Q=-. *a
Tc = N/A
A = N/A
NODE
100 -YEAR FREQUENCY DISCHARGE

TIME OF CONCENTRATION
AREA

MAJOR BASIN BOUNDARY

SUB -BASIN BOUNDARY

FLOW PATH

SOIL TYPE
N
20 10 0 20 40 60

SCALE IN FEET

GRAP HIC SCALE
N0IVITTY MAP
POC-1 FOR BAS NS (200-500)

AT MYNAH PL & MARABOU LN

PRE DRAINAGE MAP
FOR

WAXWING SUBDIVISION
SWS E NGINEERING, INC .
['IS I AHI 1,, Emu, Dr op, Sv.�~u Yams.

ISO V1n01 , CA o:0'1
! 1M.'II-tl011 11111.'II,IOI.

LEGEND
ozozi j 1-I90
OL8 IQ 69V
MCIC0.
• 600
Q, m= 0. 73
Tc = 6.0
A = 0.17

ATTENUATED
0= 0. 42 cfs >}
V = 2.6 fls
BASINJ8

0.03 A
�$4s,
800 ,
0,== 0.09
Tc = 5.0
= 0.04
700
Q,m= 4.88
Tc = 5.0
=0. 78
ATTENUATED 0
=0.59 c is
E 15660
21 Oa
ASIN-6. ' 0 .

0.17 AC
ATTENUATED 0:
7500-700
Q.= 2.02
Tc = 7. 4
• = 1. 21
V= 7.9 Vs
POC-2
BASINS (500-800)

W BOBIER DRIVE

ATTENUATED
0=0.37 cfs
V=3.0 Ns
100
Q.= 0.54
i = 5 .0
E 593O'
200

0.35 i — 5.0
200+300 `
Q. 0.88
Tc = 6.4
A = 0.20
• 300
Qmo= 0 .57
Tc = 6.0
A = 0.11,

ATTENUATED
0 = 0.36 cfs
V= 3.0Vs
BASIN -4.1
0 .038 AC
400 .1
Qm= 0 .11
Tc = 5.0
4 =0.038

ATTENUATED
0 =1 .01 cis
V= 3 .3 Es
4ra}5$1
BASIN -4 .2
"Mi I�eJr
0 .022 AC
400,2
Q., 0.06
Tc =5.0
1 i A =0.027
- �
.411 FG71111
V� J,
BASIN -4.3

0.028 AC
400.3
Q.= 0. 08
Tc = 5.0
4 =0.028
POC-1 FOR BASINS (100-400)

AT MYNAH PL & MARABOU LN
(DOWNSTREEM OF THE COL —DE —SAC)
�100�
Dm= XXX
Tc = N/A
A = N/A,,
MMI
NODE
100 —YEAR FREQUENCY DISCHARGE

TIME OF CONCENTRATION
AREA

MAJOR BASIN BOUNDARY
SUB —BASIN BOUNDARY

FLOW PATH

SOIL TYPE

LANDSCAPE AREA

BIORLTRARON AREA

IMPERVIOUS AREA (BLDG)

IMPERVIOUS AREA (CONCRETE)
IMPERVIOUS . AREA (AC)

TABULAR SUMMARY OF BASINS
BASIN

AREA (AC)

IMPERVIOUS

AREA (AC)
% IMP
HSG
AREA WEIGHTED*

COEFFICIENT
1 0 .14

0.03 21.1
D
0 .47
2 0.09

0.019
20 .2
D

0.46 3
0 .11

0.065

57.1 0.

0.66 4.1

0.038 .
0 .00

0.0 D
0 .35.
4 .2

0.022

0.00 0.0
D
0 .35
4 .3

0.028

0.00 0.0
D
0 .35
5 0.26
0 .22
84 .0
D

0.81 6
0 .17

0.059
35 .6
0 0.55
7 0 .78

0.54 70.0
D

0.73 8

0.03 0 .00

0.0 D
035
*FOR CALCULATION OF WEIGHTED C COEFFICIENT, 0.35 (SOIL TYPE "0") IS USED FOR PERVIOUS AREA, PER SAN DIEGO COUNTY HYDROLOGY MANUAL, TABLE 3- )

POST DRAINAGE MAP
FOR

WAXWING DRIVE SUBDIVISION
N
20 10 0 20 40 60

SCALE IN FEET

GRAPHIC SCALE
SWS ENGINEERING, INC.
1613 L de So 191,959 Unm, EA, 20
Sao At,,,. CA 92528
P'. 760.144.11011 A760741046

RUN OFF CONFLUENCE POINT:

BASINS 200-500 (EXISTING)
BASINS 100-400 POST

CURB INLETS

CURB INLETS

Appendix F
Priority Development Project (PDP)
Storm Water Management Plan
(SWQMP)
08/11/2026
PH2 491 of 876

Project Number(s): PC P24-0164 LD
GP

CITY OF VISTA

C A L I F O R N I A

PRIORITY DEVELOPMENT PROJECT

STORM WATER QUALITY MANAGEMENT PLAN (SWAMP)
FOR
Waxwing Drive Subdivision
552 W Bobier Drive
Vista, CA 92083
PREPARED FOR:

SWS Engineering, Inc.
1635 Lake San Marcos Drive, Suite 200
San Marcos, CA 920%8
(760) 744-0011
[email protected]
March 17, 2025
NOTE: This Priority Development Project SWQMP Template and Instructions are offered as a tool to assist users in complying with RWQCB Order No. R9-2015-0001 (Permit), and is not intended to warrant or guarantee Permit compliance, which is the independent and sole responsibility of the user. This template is subject to revision without notice, at any time.
08/11/2026
PH2 492 of 876

ENGINEER OF WORK CERTIFICATION STATEMENT 3
CONTENTS PROJECT OWNER CERTIFICATION STATEMENT 4
CITY OF VISTA STAFF REVIEW 5
PROJECT VICINITY MAP 7
FORM 1- PROJECT CATEGORY DETERMINATION CHECKLIST 8
FORM 2 - PROJECT OVERVIEW 9
DESCRIPTION OF EXISTING SITE CONDITIONS 10
DESCRIPTION OF EXISTING SITE DRAINAGE PATTERNS 11
DESCRIPTION OF PROPOSED SITE DEVELOPMENT 12
DESCRIPTION OF PROPOSED SITE DRAINAGE PATTERNS 13
POTENTIAL POLLUTANT SOURCE AREAS 15
IDENTIFICATION AND NARRATIVE OF RECEIVING WATER AND POLLUTANTS OF CONCERN 16 HYDROMODIFICATION MANAGEMENT REQUIREMENTS 18
CRITICAL COARSE SEDIMENT YIELD AREAS 19
FLOW CONTROL FOR POST -PROJECT RUNOFF 20
OTHER SITE REQUIREMENTS AND CONSTRAINTS 21
FORM 3 - SOURCE CONTROL BMPS FOR ALL DEVELOPMENT PROJECTS 22 PROJECT IDENTIFICATION & SOURCE CONTROLS 22
FORM 4 - SITE DESIGN BMPS FOR ALL DEVELOPMENT PROJECTS 26 PROJECT IDENTIFICATION 26
FORM 5 - STRUCTURAL POLLUTANT CONTROL AND HYDROMODIFICATION MANAGEMENT BMPS 28 PROJECT IDENTIFICATION 28
PDP STRUCTURAL BMPS 28
FORM 6-STORMWATER BMP MAINTENANCE MECHANISM 29
PROJECT IDENTIFICATION 29
MAINTENANCE REQUIREMENTS 29
ATTACHMENT 1- POLLUTANT CONTROLS: SUPPORT DOCUMENT AND CHECKLIST 30 ATTACHMENT 1A - DMA EXHIBIT CHECKLIST 31
ATTACHMENT 1B - TEMPLATE TABULAR DMA SUMMARY 32
ATTACHMENT 2 - HYDROMODIFICATION MANAGEMENT CONTROLS: SUPPORT DOCUMENTATION & CHECKLIST 33 ATTACHMENT 2A - HYDROMODIFICATION MANAGEMENT EXHIBIT 34 ATTACHMENT 3 - BMP MAINTENANCE INFORMATION 35
ATTACHMENT 3A - MAINTENANCE PLAN REQUIREMENTS 36
ATTACHMENT 3B - MAINTENANCE AGREEMENT 37
ATTACHMENT 4 - REQUIREMENTS FOR CONSTRUCTION PLANS 38
08/11/2026