Riverside City Council
April 22, 2025

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Project Specific Water Quality Management Plan
A Template for Projects located within the Santa Ana Watershed Region of Riverside County

Project Title: TRACT 38921
Development No : P24-XXXX
Design Review/Case No: DP-2023-01293

Original Date Prepared
: February 22, 2024
Revision Date(s) : Insert text here
Prepared for Compliance with
Regional Board Order No . R8-2010-0033
Template revised June 30, 2016

Contact Information:

Prepared for:

La Sierra Victoria Development LLC
19215 Wild Mustang Court
Apple Valley, CA 92307

Prepared by:

6879 AIRPORT DRIVE
RIVERSIDE, CA, 92504
TEL: 951.688.0241
EMAIL:
[email protected]
Michael R. Brendecke
Preliminary
Final
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OWNER’S CERTIFICATION

This Project-Specific Water Quality Management Plan (WQMP) has been prepared for La Sierra Victoria Development LLC by Adkan Engineers for the Tract 38921, located on southeast corner of Victoria Avenue and La Sierra Avenue.

This WQMP is intended to comply with the requirements of City of Riverside for Tentative tract map. Planning Case No. DP-2023-01293 which includes the requirement for the preparation and implementation of a Project-Specif ic WQMP.

The undersigned, while owning the property/project described in the preceding paragraph, shall be responsible for the implementation and funding of this WQMP and will ensure that this WQMP is amended as appropriate to reflect up-to-date conditions on the site. In addition, th e property owner accepts responsibility for interim operation and maintenance of Stormwater BMPs until such time as t his responsibility is formally transferred to a sub sequent owner. This WQMP will be reviewed with the facility operator, facility supervisors, employees, tenants, maintenance and service contractors, or any other party (or par ties) having responsibility for implementing portio ns of this WQMP. At least one copy of this WQMP will be maint ained at the project site or project office in perp etuity. The undersigned is authorized to certify and to approve implementation of this WQMP. The undersigned is a ware that implementation of this WQMP is enforceable under
city of riverside Water Quality Ordinance (Municipal Code Section 14.12.315).
"I, the undersigned, certify under penalty of law that the provisions of this WQMP have been reviewed and accepted and that the WQMP will be transferred to future successors in interest."

Owner’s Signature Date

Owner’s Printed Name Owner’s Title/Position

PREPARER’S CERTIFICATION

“The selection, sizing and design of stormwater tre atment and other stormwater quality and quantity co ntrol measures in this plan meet the requirements of Regional Water Quality Control Board Order No. R8-2010-0033 and any subsequent amendments thereto.”

Preparer’s Signature Date

Michael Brendecke Senior Project Manager
Preparer’s Printed Name Preparer’s Title/Posi tion

Preparer’s Licensure:

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Table of Contents
Section A: Project and Site Information........................................................................................................ 6 A.1 Maps and Site Plans ............................................................................................................................ 6 A.2 Identify Receiving Waters ................................................................................................................... 7 A.3 Additional Permits/Approvals required for the Project: .................................................................... 7 Section B: Optimize Site Utilization (LID Principles) ..................................................................................... 8 Section C: Delineate Drainage Management Areas (DMAs) ......................................................................... 9 Section D: Implement LID BMPs ................................................................................................................. 11 D.1 Infiltration Applicability .................................................................................................................... 11 D.2 Harvest and Use Assessment ............................................................................................................ 12 D.3 Bioretention and Biotreatment Assessment .................................................................................... 14 D.4 Feasibility Assessment Summaries ................................................................................................... 15 D.5 LID BMP Sizing .................................................................................................................................. 16 Section E: Alternative Compliance (LID Waiver Program) .......................................................................... 17 E.1 Identify Pollutants of Concern .......................................................................................................... 18 E.2 Stormwater Credits ........................................................................................................................... 19 E.3 Sizing Criteria ..................................................................................................................................... 19 E.4 Treatment Control BMP Selection .................................................................................................... 20 Section F: Hydromodification ..................................................................................................................... 21 F.1 Hydrologic Conditions of Concern (HCOC) Analysis .......................................................................... 21 F.2 HCOC Mitigation ................................................................................................................................ 22 Section G: Source Control BMPs ................................................................................................................. 23 Section H: Construction Plan Checklist ....................................................................................................... 25 Section I: Operation, Maintenance and Funding ........................................................................................ 26

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List of Tables
Table A.1 Identification of Receiving Waters ................................................................................................ 7 Table A.2 Other Applicable Permits .............................................................................................................. 7 Table C.1 DMA Classifications ....................................................................................................................... 9 Table C.2 Type ‘A’, Self-Treating Areas ......................................................................................................... 9 Table C.3 Type ‘B’, Self-Retaining Areas ....................................................................................................... 9 Table C.4 Type ‘C’, Areas that Drain to Self-Retaining Areas ...................................................................... 10 Table C.5 Type ‘D’, Areas Draining to BMPs ............................................................................................... 10 Table D.1 Infiltration Feasibility .................................................................................................................. 11 Table D.2 LID Prioritization Summary Matrix ............................................................................................. 15 Table D.3 DCV Calculations for LID BMPs ................................................................................................... 16 Table E.1 Potential Pollutants by Land Use Type ........................................................................................ 18 Table E.2 Water Quality Credits .................................................................................................................. 19 Table E.3 Treatment Control BMP Sizing .................................................................................................... 19 Table E.4 Treatment Control BMP Selection .............................................................................................. 20 Table F.1 Hydrologic Conditions of Concern Summary .............................................................................. 21 Table G.1 Permanent and Operational Source Control Measures ............................................................. 24 Table H.1 Construction Plan Cross-reference ............................................................................................. 25

List of Appendices
Appendix 1: Maps and Site Plans ................................................................................................................ 27 Appendix 2: Construction Plans .................................................................................................................. 28 Appendix 3: Soils Information ..................................................................................................................... 29 Appendix 4: Historical Site Conditions ........................................................................................................ 30 Appendix 5: LID Infeasibility ........................................................................................................................ 31 Appendix 6: BMP Design Details ................................................................................................................. 32 Appendix 7: Hydromodification .................................................................................................................. 33 Appendix 8: Source Control ........................................................................................................................ 34 Appendix 9: O&M ....................................................................................................................................... 35 Appendix 10: Educational Materials ....................................................................................................... - 36 -

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Section A: Project and Site Information

PROJECT INFORMATION
Type of Project: Residential
Planning Area: La Sierra South
Community Name: La Sierra South
Development Name: TRACT 38921

PROJECT LOCATION
Latitude & Longitude (DMS): 33°88’76”N 117°27’43”W
Project Watershed and Sub-Watershed: Prado Basin/Temescal Creek, Reach 1 Gross Acres: 10.8
APN(s): 136-220-016
Map Book and Page No.: Thomas Guide 2008 Edition, Page 744, Grid G-3

PROJECT CHARACTERISTICS
Proposed or Potential Land Use(s) Residential
Proposed or Potential SIC Code(s) 1521
Area of Impervious Project Footprint (SF) 341,993
Total Area of proposed Impervious Surfaces within the Project Footprint (SF)/or Replacement 341,993 Does the project consist of offsite road improvements? Y N Does the project propose to construct unpaved roads? Y N Is the project part of a larger common plan of development (phased project)? Y N

EXISTING SITE CHARACTERISTICS
Total area of existing Impervious Surfaces within the Project limits Footprint (SF) 4943 Is the project located within any MSHCP Criteria Cell? Y N If so, identify the Cell number:

Are there any natural hydrologic features on the project site? Y N Is a Geotechnical Report attached? Y N
If no Geotech. Report, list the NRCS soils type(s) present on the site (A, B, C and/or D) What is the Water Quality Design Storm Depth for the project? 0.56 in

A.1 Maps and Site Plans
When completing your Project-Specific WQMP, include a map of the local vicinity and existing site. In addition, include all grading, drainage, landscape/plant palette and other pertinent construction plans in Appendix 2. At a minimum , your WQMP Site Plan should include the following:

• Drainage Management Areas
• Proposed Structural BMPs
• Drainage Path
• Drainage Infrastructure, Inlets, Overflows
• Source Control BMPs
• Buildings, Roof Lines, Downspouts
• Impervious Surfaces
• Standard Labeling
• BMP Locations (Lat/Long)
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A.2 Identify Receiving Waters
Using Table A.1 below, list in order of upstream to downstream, the receiving waters that the project site is tributary to. Continue to fill each row with the Receiving Water’s 303(d) listed impairments (if an y), designated beneficial uses, and proximity, if any, to a RARE beneficial use. Include a map of the receiving waters in Appendix 1.

Table A.1 Identification of Receiving Waters
Receiving Waters EPA Approved 303(d) List
Impairments
Designated
Beneficial Uses
Proximity to RARE
Beneficial Use
Arizona Channel 8.8 mi
Arlington Channel 7.5 mi
Temescal Creek, Reach 1 pH REC1. REC2. WARM, WILD 2 .7 mi Prado Creek Basin Nutrients, Pathogens, TSS REC1. REC2. WARM, WILD, RARE

A.3 Additional Permits/Approvals required for the Project:

Table A.2 Other Applicable Permits
Agency Permit Required
State Department of Fish and Game, 1602 Streambed Alteration Agreement Y N State Water Resources Control Board, Clean Water Act (CWA) Section 401 Water Quality Cert. Y N US Army Corps of Engineers, CWA Section 404 Permit Y N US Fish and Wildlife, Endangered Species Act Section 7 Biological Opinion Y N Statewide Construction General Permit Coverage Y N
Statewide Industrial General Permit Coverage Y N
Western Riverside MSHCP Consistency Approval (e.g., JPR, DBESP) Y N Other (please list in the space below as required)
City of Riverside Building permit
City of Riverside Grading permit
City of Riverside Construction Permit
Y N
If yes is answered to any of the questions above, t he Co-Permittee may require proof of approval/coverage from those agencies as applicable including documentation of any associated requirements that may affect this Project-Specific WQMP.

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Section B: Optimize Site Utilization (LID Principles)
Site Optimization
Did you identify and preserve existing drainage patterns? If so, how? If not, why? Yes, the grading design preserves the historic drainage patterns north to Victoria Avenue.

Did you identify and protect existing vegetation? If so, how? If not, why? Some, where possible. The project site is currently orange groves which will need to be removed in order to develop the site. The orange groves will b e preserved at the northerly edge of site along Victoria Ave up to 100’ from the edge of roadway in accordance with the Victoria Ave policy.

Did you identify and preserve natural infiltration capacity? If so, how? If not, why? Natural infiltration capacity was preserved with the implementation of an onsite infiltration basin.

Did you identify and minimize impervious area? If so, how? If not, why? Impervious areas were minimized to the maximum exte nt practicable. Landscaping is being incorporated into the site in all feasible areas.

Did you identify and disperse runoff to adjacent pervious areas? If so, how? If not, why? Onsite drainage will be conveyed to a proposed infiltration basin at the north east corner of the site via surface drainage and a storm drain system.

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Section C: Delineate Drainage Management Areas
(DMAs)
Utilizing the procedure in Section 3.3 of the WQMP Guidance Document which discusses the methods of delineating and mapping your project site into indi vidual DMAs, complete Table C.1 below to appropriately categorize the types of classificatio n (e.g., Type A, Type B, etc.) per DMA for your pro ject site. Upon completion of this table, this informati on will then be used to populate and tabulate the corresponding tables for their respective DMA classifications.

Table C.1 DMA Classifications
DMA Name or ID Surface Type(s) 12 Area (Sq. Ft.) DMA Type C1 Roofs 132,538 C
C2 Streets 65,141 C
C3 Landscaping 111,239 C
B1 Natural A Soil (infiltration
basin)
3,674 B

1Reference Table 2-1 in the WQMP Guidance Document to populate this column 2If multi-surface provide back-up

Table C.2 Type ‘A’, Self-Treating Areas
DMA Name or ID Area (Sq. Ft.) Stabilization Type Irrigation Type (if any) A1 29,400 Existing orange groves

Table C.3 Type ‘B’, Self-Retaining Areas
Self-Retaining Area
Type ‘C’ DMAs that are draining to the Self- Retaining
Area
DMA
Name/ ID
Post-project
surface type
Area
(square
feet)
Storm
Depth
(inches) DMA Name /
ID
[C] from Table C.4 =
Required Retention Depth
(inches)
[A] [B] [C] [D]
B1
Natural A Soil
(infiltration
basin)
3674 0.56 C1 132538 11.3
C2 65141 5.6
C3 11123.9 0.9
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 =
 +

 ∙




Table C.4 Type ‘C’, Areas that Drain to Self-Retaining Areas DMA Receiving Self-Retaining DMA
DMA Name/ ID
Area
(square feet)
Post -project
surface type
Impervious
fraction
Product
DMA name /ID
Area (square
feet) Ratio
[A] [B] [C] = [A] x [B] [D] [C]/[D]
C1 132538 Roofs 1.00 132538 B1 3674 36.07
C2 65141 Concrete/Asphalt1.00 65141 B1 3674 17.73
C3 11139 Ornamental
Landscaping

0.10 11123.9 B1 3674 3.03

Table C.5 Type ‘D’, Areas Draining to BMPs
DMA Name or ID BMP Name or ID

Note: More than one drainage management area can drain to a single LID BMP, however, one drainage management area may not drain to more than one BMP.

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Section D: Implement LID BMPs
D.1 Infiltration Applicability
Is there an approved downstream ‘Highest and Best Use’ for stormwater runoff (see discussion in Chapter

2.4.4 of the WQMP Guidance Document for further details)? Y N If yes has been checked, Infiltration BMPs shall not be used for the site; proceed to section D.3 If no, continue working through this section to imp lement your LID BMPs. It is recommended that you contact your Co-Permittee to verify whether or not your project discharges to an approved downstream ‘Highest and Best Use’ feature.

Geotechnical Report
A Geotechnical Report or Phase I Environmental Site Assessment may be required by the Copermittee to confirm present and past site characteristics that may affect the use of Infiltration BMPs. In addition, the Co-Permittee, at their discretion, may not require a geotechnical report for small projects as described in Chapter 2 of the WQMP Guidance Document. If a geote chnical report has been prepared, include it in Appendix 3. In addition, if a Phase I Environmental Site Assessment has been prepared, include it in Appendix 4.

Is this project classified as a small project consi stent with the requirements of Chapter 2 of the WQM P Guidance Document?
Y N
Infiltration Feasibility
Table D.1 below is meant to provide a simple means of assessing which DMAs on your site support Infiltration BMPs and is discussed in the WQMP Guid ance Document in Chapter 2.4.5. Check the appropriate box for each question and then list affected DMAs as applicable. If additional space is needed, add a row below the corresponding answer.

Table D.1 Infiltration Feasibility
Does the project site… YES NO
…have any DMAs with a seasonal high groundwater mark shallower than 10 feet? X If Yes, list affected DMAs:
…have any DMAs located within 100 feet of a water supply well? X If Yes, list affected DMAs:
…have any areas identified by the geotechnical report as posing a public safety risk where infiltration of stormwater could have a negative impact?
X
If Yes, list affected DMAs:
…have measured in-situ infiltration rates of less than 1.6 inches / hour? X If Yes, list affected DMAs:
…have significant cut and/or fill conditions that w ould preclude in-situ testing of infiltration rates at the final infiltration surface?
X
If Yes, list affected DMAs:
…geotechnical report identify other site-specific factors that would preclude effective and safe infiltration? X Describe here:

If you answered “Yes” to any of the questions above for any DMA, Infiltration BMPs should not be used for those DMAs and you should proceed to the assessment for Harvest and Use below.

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D.2 Harvest and Use Assessment
Please check what applies :
☐ Reclaimed water will be used for the non-potable water demands for the project. ☐Downstream water rights may be impacted by Harvest and Use as approved by the Regional Board (verify with the Copermittee).
☐The Design Capture Volume will be addressed using I nfiltration Only BMPs. In such a case, Harvest and Use BMPs are still encouraged, but it w ould not be required if the Design Capture Volume will be infiltrated or evapotranspired.

If any of the above boxes have been checked, Harvest and Use BMPs need not be assessed for the site. If none of the above criteria applies, follow the steps below to assess the feasibility of irrigation use, toilet use and other non-potable uses (e.g., industrial use).

Irrigation Use Feasibility
Complete the following steps to determine the feasi bility of harvesting stormwater runoff for Irrigati on Use BMPs on your site:

Step 1: Identify the total area of irrigated landsc ape on the site, and the type of landscaping used.

Total Area of Irrigated Landscape : n/a
Type of Landscaping (Conservation Design or Active Turf) : Conservation design Step 2: Identify the planned total of all imperviou s areas on the proposed project from which runoff might be feasibly captured and stored for irrigatio n use. Depending on the configuration of buildings and other impervious areas on the site, you may consider the site as a whole, or parts of the site, to evaluate reasonable scenarios for capturing and storing runoff and directing the stored runoff to the potential use(s) identified in Step 1 above.

Total Area of Impervious Surfaces: n/a
Step 3: Cross reference the Design Storm depth for the project site (see Exhibit A of the WQMP Guidance Document) with the left column of Table 2-3 in Chapter 2 to determine the minimum area of Effective Irrigated Area per Tributary Impervious Area (EIATIA).

Enter your EIATIA factor : n/a
Step 4: Multiply the unit value obtained from Step 3 by the total of impervious areas from Step 2 to develop the minimum irrigated area that would be required.

Minimum required irrigated area : n/a
Step 5: Determine if harvesting stormwater runoff f or irrigation use is feasible for the project by comparing the total area of irrigated landscape (Step 1) to the minimum required irrigated area (Step 4).

Minimum required irrigated area (Step 4) Available Irrigated Landscape (Step 1) n/a n/a

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Toilet Use Feasibility
Complete the following steps to determine the feasi bility of harvesting stormwater runoff for toilet flushing uses on your site:

Step 1: Identify the projected total number of dail y toilet users during the wet season, and account for any periodic shut downs or other lapses in occupancy:

Projected Number of Daily Toilet Users: n/a
Project Type: Residential
Step 2: Identify the planned total of all imperviou s areas on the proposed project from which runoff might be feasibly captured and stored for toilet us e. Depending on the configuration of buildings and other impervious areas on the site, you may consider the site as a whole, or parts of the site, to evaluate reasonable scenarios for capturing and storing runoff and directing the stored runoff to the potential use(s) identified in Step 1 above.

Total Area of Impervious Surfaces: n/a
Step 3: Enter the Design Storm depth for the projec t site (see Exhibit A) into the left column of Table 2- 2 in Chapter 2 to determine the minimum number or toilet users per tributary impervious acre (TUTIA).

Enter your TUTIA factor: n/a
Step 4: Multiply the unit value obtained from Step 3 by the total of impervious areas from Step 2 to develop the minimum number of toilet users that would be required.

Minimum number of toilet users: n/a
Step 5: Determine if harvesting stormwater runoff f or toilet flushing use is feasible for the project by comparing the Number of Daily Toilet Users (Step 1) to the minimum required number of toilet users (Step 4).

Minimum required Toilet Users (Step 4) Projected nu mber of toilet users (Step 1)

Other Non-Potable Use Feasibility

Are there other non-potable uses for stormwater runoff on the site (e.g. industrial use)? See Chapter 2 of the Guidance for further information. If yes, describe below. If no, write N/A.

N/A
Step 1: Identify the projected average daily non-po table demand, in gallons per day, during the wet season and accounting for any periodic shut downs or other lapses in occupancy or operation.

Average Daily Demand: N/A
Step 2: Identify the planned total of all imperviou s areas on the proposed project from which runoff might be feasibly captured and stored for the ident ified non-potable use. Depending on the configuration of buildings and other impervious areas on the site, you may consider the site as a whole, or parts of the site, to evaluate reasonable scenarios for capturing and storing runoff and directing the stored runoff to the potential use(s) identified in Step 1 above.

Total Area of Impervious Surfaces: N/A
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Step 3: Enter the Design Storm depth for the projec t site (see Exhibit A) into the left column of Table 2- 4 in Chapter 2 to determine the minimum demand for non-potable uses per tributary impervious acre.

Enter the factor from Table 2-4: N/A
Step 4: Multiply the unit value obtained from Step 3 by the total of impervious areas from Step 2 to develop the minimum number of gallons per day of non-potable use that would be required.

Minimum required use: N/A
Step 5: Determine if harvesting stormwater runoff f or other non-potable use is feasible for the project by comparing the projected average daily use (Step 1) to the minimum required non-potable use (Step 4).

Minimum required non-potable use (Step 4) Projected average daily use (Step 1)

N/A N/A

If Irrigation, Toilet and Other Use feasibility ant icipated demands are less than the applicable minim um values, Harvest and Use BMPs are not required and y ou should proceed to utilize LID Bioretention and Biotreatment per Section 3.4.2 of the WQMP Guidance Document.

D.3 Bioretention and Biotreatment Assessment
Other LID Bioretention and Biotreatment BMPs as des cribed in Chapter 2.4.7 of the WQMP Guidance Document are feasible on nearly all development sites with sufficient advance planning.

Select one of the following:
☐ LID Bioretention/Biotreatment BMPs will be used for some or all DMAs of the project as noted below in Section D.4 (note the requirements of Section 3.4.2 in the WQMP Guidance Document). ☐ A site-specific analysis demonstrating the technic al infeasibility of all LID BMPs has been performed and is included in Appendix 5. If you pla n to submit an analysis demonstrating the technical infeasibility of LID BMPs, request a pre- submittal meeting with the Copermittee to discuss this option. Proceed to Section E to document your alternative compliance measures.

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D.4 Feasibility Assessment Summaries
From the Infiltration, Harvest and Use, Bioretention and Biotreatment Sections above, complete Table D.2 below to summarize which LID BMPs are technically f easible, and which are not, based upon the established hierarchy.

Table D.2 LID Prioritization Summary Matrix
DMA
Name/ID
LID BMP Hierarchy No LID
(Alternative
Compliance) 1. Infiltration 2. Harvest and use 3. Bioretention 4. Biotreatment B1
C1
C2
C3

For those DMAs where LID BMPs are not feasible, provide a brief narrative below summarizing why they are not feasible, include your technical infeasibility criteria in Appendix 5, and proceed to Section E below to document Alternative Compliance measures for tho se DMAs. Recall that each proposed DMA must pass through the LID BMP hierarchy before alternative compliance measures may be considered.

N/A

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D.5 LID BMP Sizing
Each LID BMP must be designed to ensure that the De sign Capture Volume will be addressed by the selected BMPs. First , calculate the Design Capture Volume for each LID BMP using the V BMP worksheet in Appendix F of the LID BMP Design Handbook. Second , design the LID BMP to meet the required V BMP using a method approved by the Copermittee. Utilize the worksheets found in the LID BMP Design Handbook or consult with your Copermittee to assist you in correctly sizing your LID BMPs. Complete Table D.3 below to document the Design Capture Volume and the Propo sed Volume for each LID BMP. Provide the completed design procedure sheets for each LID BMP in Appendix 6. You may add additional rows to the table below as needed.

Table D.3 DCV Calculations for LID BMPs
DMA
Type/ID
DMA
Area
(square
feet)
Post-Project
Surface Type
Effective
Impervious
Fraction, I f
DMA
Runoff
Factor
DMA
Areas x
Runoff
Factor
B1: Infiltration Basin
[A] [B] [C] [A] x [C]
C1 132538 ROOFS 1.00 0. 89 118223.9
Design
Storm
Depth
(in)
Design
Capture
Volume,
VBMP (cubic
feet)
Proposed
Volume
on Plans
(cubic
feet)
C2 65141 CONCRETE OR

ASPHALT

1.00 0.89 58105.8
C3 111239 ORNAMENTAL

LANDSCAPING

0.10 0.11 12287.2
B1 3674 NATURAL
(A SOIL)

0.03 0.06 229.8

312592 188846.7 0.56 8812.8 9177.5
[B], [C] is obtained as described in Section 2.3.1 of the WQMP Guidance Document [E] is obtained from Exhibit A in the WQMP Guidance Document [G] is obtained from a design procedure sheet, such as in LID BMP Design Handbook and placed in Appendix 6

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Section E: Alternative Compliance (LID Waiver Program) LID BMPs are expected to be feasible on virtually all projects. Where LID BMPs have been demonstrated to be infeasible as documented in Section D, other Treatment Control BMPs must be used (subject to LID waiver approval by the Copermittee). Check one of the following Boxes:
☒ LID Principles and LID BMPs have been incorporated into the site design to fully address all Drainage Management Areas. No alternative compliance measures are required for this project and thus this Section is not required to be completed.
- Or -
☐ The following Drainage Management Areas are unable to be addressed using LID BMPs. A site- specific analysis demonstrating technical infeasibility of LID BMPs has been approved by the Co- Permittee and included in Appendix 5. Additionally, no downstream regional and/or sub-regional LID BMPs exist or are available for use by the proj ect. The following alternative compliance measures on the following pages are being implement ed to ensure that any pollutant loads expected to be discharged by not incorporating LID BMPs, are fully mitigated.

List DMAs here.

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E.1 Identify Pollutants of Concern
Utilizing Table A.1 from Section A above which noted your project’s receiving waters and their associated EPA approved 303(d) listed impairments, cross refer ence this information with that of your selected Priority Development Project Category in Table E.1 below. If the identified General Pollutant Categories are the same as those listed for your receiving waters, then these will be your Pollutants of Concern and the appropriate box or boxes will be checked on the last row. The purpose of this is to document compliance and to help you appropriately plan for m itigating your Pollutants of Concern in lieu of implementing LID BMPs.

Table E.1 Potential Pollutants by Land Use Type
Priority Development
Project Categories and/or
Project Features (check those
that apply)
General Pollutant Categories
Bacterial
Indicators Metals Nutrients Pesticides
Toxic
Organic
Compounds
Sediments Trash &
Debris
Oil &
Grease
Detached Residential
Development P N P P N P P P
Attached Residential
Development P N P P N P P P (2)
Commercial/Industrial
Development P
(3) P P (1) P (1) P (5) P (1) P P
Automotive Repair
Shops N P N N P (4, 5) N P P
Restaurants
(>5,000 ft
2) P N N N N N P P
Hillside Development
(>5,000 ft
2) P N P P N P P P
Parking Lots
(>5,000 ft
2) P(6) P P (1) P (1) P (4) P (1) P P
Retail Gasoline Outlets N P N N P N P P
Project Priority Pollutant(s)
of Concern
P = Potential
N = Not Potential
(1) A potential Pollutant if non-native landscaping exists or is proposed onsite; otherwise not expected (2) A potential Pollutant if the project includes uncovered parking areas; otherwise not expected (3) A potential Pollutant is land use involving animal waste (4) Specifically petroleum hydrocarbons
(5) Specifically solvents
(6) Bacterial indicators are routinely detected in pavement runoff

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E.2 Stormwater Credits
Projects that cannot implement LID BMPs but neverth eless implement smart growth principles are potentially eligible for Stormwater Credits. Utiliz e Table 3-8 within the WQMP Guidance Document to identify your Project Category and its associated Water Quality Credit. If not applicable, write N/A.

Table E.2 Water Quality Credits
Qualifying Project Categories Credit Percentage 2

Total Credit Percentage 1
1Cannot Exceed 50%
2Obtain corresponding data from Table 3-8 in the WQMP Guidance Document

E.3 Sizing Criteria
After you appropriately considered Stormwater Credi ts for your project, utilize Table E.3 below to appropriately size them to the DCV, or Design Flow Rate, as applicable. Please reference Chapter 3.5.2 of the WQMP Guidance Document for further information.

Table E.3 Treatment Control BMP Sizing
DMA
Type/ID
DMA
Area
(square
feet)
Post-
Project
Surface
Type
Effective
Impervious
Fraction, I f
DMA
Runoff
Factor
DMA
Area x
Runoff
Factor

Enter BMP Name / Identifier Here

[A] [B] [C] [A] x [C]

Design
Storm
Depth
(in)
Minimum
Design
Capture
Volume or
Design Flow
Rate (cubic
feet or cfs)

Total Storm
Water
Credit %
Reduction

Proposed
Volume
or Flow
on Plans
(cubic
feet or
cfs)

AT =
Σ[A]
Σ= [D] [E]
F =
Dx
E

G [F] X (1-[H]) [I]
[B], [C] is obtained as described in Section 2.3.1 from the WQMP Guidance Document [E] is for Flow-Based Treatment Control BMPs [E] = .2, for Volume-Based Control Treatment BMPs, [E] obtained from Exhibit A in the WQMP Guidance Document
[G] is for Flow-Based Treatment Control BMPs [G] = 43,560, for Volume-Based Control Treatment BMPs, [G] = 12 [H] is from the Total Credit Percentage as Calculated from Table E.2 above [I] as obtained from a design procedure sheet from the BMP manufacturer and should be included in Appendix 6

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E.4 Treatment Control BMP Selection
Treatment Control BMPs typically provide proprietary treatment mechanisms to treat potential pollutants in runoff, but do not sustain significant biological processes. Treatment Control BMPs must have a removal efficiency of a medium or high effectiveness as quantified below:
• High : equal to or greater than 80% removal efficiency • Medium : between 40% and 80% removal efficiency
Such removal efficiency documentation (e.g., studies, reports, etc.) as further discussed in Chapter 3.5.2 of the WQMP Guidance Document, must be included in Appendix 6. In addition, ensure that proposed Treatment Control BMPs are properly identified on the WQMP Site Plan in Appendix 1.

Table E.4 Treatment Control BMP Selection
Selected Treatment Control BMP
Name or ID 1
Priority Pollutant (s) of
Concern to Mitigate 2
Removal Efficiency
Percentage 3

1 Treatment Control BMPs must not be constructed within Receiving Waters. In addition, a proposed Treatment Control BMP may be listed more than once if they possess more than one qualifying pollutant removal efficiency. 2 Cross Reference Table E.1 above to populate this column. 3 As documented in a Co-Permittee Approved Study and provided in Appendix 6.

- 21 -

Section F: Hydromodification
F.1 Hydrologic Conditions of Concern (HCOC) Analysis
Once you have determined that the LID design is ade quate to address water quality requirements, you will need to assess if the proposed LID Design may still create a HCOC. Review Chapters 2 and 3 (including Figure 3-7) of the WQMP Guidance Document to determ ine if your project must mitigate for Hydromodification impacts. If your project meets one of the following criteria which will be indicated by the check boxes below, you do not need to address H ydromodification at this time. However, if the project does not qualify for Exemptions 1, 2 or 3, then additional measures must be added to the design to comply with HCOC criteria. This is discussed in further detail below in Section F.2.

HCOC EXEMPTION 1: The Priority Development Project disturbs less than one acre. The Copermittee has the discretion to require a Project-Specific WQ MP to address HCOCs on projects less than one acre on a case by case basis. The disturbed area calculation should include all disturbances associated with larger common plans of development.

Does the project qualify for this HCOC Exemption? Y N If Yes, HCOC criteria do not apply.

HCOC EXEMPTION 2: The volume and time of concentration 1 of storm water runoff for the post- development condition is not significantly different from the pre-development condition for a 2-year return frequency storm (a difference of 5% or less is considered insignificant) using one of the following methods to calculate:
• Riverside County Hydrology Manual
• Technical Release 55 (TR-55): Urban Hydrology for S mall Watersheds (NRCS 1986), or derivatives thereof, such as the Santa Barbara Urban Hydrograph Method • Other methods acceptable to the Co-Permittee

Does the project qualify for this HCOC Exemption?
Y N
If Yes, report results in Table F.1 below and provi de your substantiated hydrologic analysis in Appendix 7.

Table F.1 Hydrologic Conditions of Concern Summary
2 year – 24 hour
Pre-condition Post-condition % Difference
Time of
Concentration

INSERT VALUE
Volume (Cubic Feet) INSERT VALUE
1 Time of concentration is defined as the time after the beginning of the rainfall when all portions of the drainage basin are contributing to flow at the outlet.

- 22 -

HCOC EXEMPTION 3: All downstream conveyance channels to an adequate sump (for example, Prado Dam, Lake Elsinore, Canyon Lake, Santa Ana Ri ver, or other lake, reservoir or naturally erosion resistant feature) that will receive runoff from the project are engineered and regularly maintained to ensure design flow capacity; no sensitive stream habitat areas will be adversely affected; or are not identified on the Co-Permittees Hydromodification Susceptibility Maps.

Does the project qualify for this HCOC Exemption? Y N If Yes, HCOC criteria do not apply and note below w hich adequate sump applies to this HCOC qualifier:

INSERT TEXT HERE

F.2 HCOC Mitigation
If none of the above HCOC Exemption Criteria are applicable, HCOC criteria is considered mitigated if they meet one of the following conditions:
a. Additional LID BMPS are implemented onsite or offsite to mitigate potential erosion or habitat impacts as a result of HCOCs. This can be conducted by an evaluation of site-specific conditions utilizing accepted professional methodol ogies published by entities such as the California Stormwater Quality Association (CASQA), the Southern California Coastal Water Research Project (SCCRWP), or other Co-Permittee approved methodologies for site-specific HCOC analysis.

b. The project is developed consistent with an approved Watershed Action Plan that addresses HCOC in Receiving Waters.

c. Mimicking the pre-development hydrograph with the post-development hydrograph, for a 2- year return frequency storm. Generally, the hydrolo gic conditions of concern are not significant, if the post-development hydrograph is no more than 10% greater than pre- development hydrograph. In cases where excess volume cannot be infiltrated or captured and reused, discharge from the site must be limited to a flow rate no greater than 110% of the pre-development 2-year peak flow.

Be sure to include all pertinent documentation used in your analysis of the items a, b or c in Appendix 7.

- 23 -

Section G: Source Control BMPs
Source control BMPs include permanent, structural features that may be required in your project plans — such as roofs over and berms around trash and recycling areas — and Operational BMPs, such as regular sweeping and “housekeeping”, that must be implement ed by the site’s occupant or user. The MEP standard typically requires both types of BMPs. In general, Operational BMPs cannot be substituted for a feasible and effective permanent BMP. Using the Pollutant Sources/Source Control Checklist in Appendix 8, review the following procedure to specify Source Control BMPs for your site:

1. Identify Pollutant Sources : Review Column 1 in the Pollutant Sources/Source Control Checklist. Check off the potential sources of Pollutants that apply to your site.

2. Note Locations on Project-Specific WQMP Exhibit : Note the corresponding requirements listed in Column 2 of the Pollutant Sources/Source Control Ch ecklist. Show the location of each Pollutant source and each permanent Source Control BMP in you r Project-Specific WQMP Exhibit located in Appendix 1.

3. Prepare a Table and Narrative : Check off the corresponding requirements listed in Column 3 in the Pollutant Sources/Source Control Checklist. In the left column of Table G.1 below, list each potential source of runoff Pollutants on your site (from those that you checked in the Pollutant Sources/Source Control Checklist). In the middle column, list the corresponding permanent, Structural Source Control BMPs (from Columns 2 and 3 of the Pollutant Sources /Source Control Checklist) used to prevent Pollutants from entering runoff. Add additional narrative in this column that explains any special features, materials or methods of construction that will be used to implement these permanent, Structural Source Control BMPs.

4. Identify Operational Source Control BMPs: To complete your table, refer once again to the Pollutant Sources/Source Control Checklist. List in the right column of your table the Operational BMPs that should be implemented as long as the anticipated ac tivities continue at the site. Copermittee stormwater ordinances require that applicable Source Control BMPs be implemented; the same BMPs may also be required as a condition of a use permit or other revocable Discretionary Approval for use of the site.

- 24 -

Table G.1 Permanent and Operational Source Control Measures Potential Sources of Runoff
pollutants
Permanent Structural Source
Control BMPs
Operational Source Control BMPs
Onsite storm drains inlets • Mark all inlet with the
words “only rain down
storm drain” or similar.

Catch basin markers may
be available from the
Riverside County Flood
Control and Water
Conservation District, call
951.55.1200 to verify
• Maintain and periodically
repaint
or replace inlet markings
• Provide Stormwater pollution
prevention information to new
site owners, lessees, or
operators.
• See applicable optional BMPs in

Fact Sheet SC-44, “Drainage
System Maintenance,” in the
CASQA Stormwater Quality
Handbooks at www.
cabmphandbooks.com
• Include the following in lease
agreements: “Tenant shall not
allow anyone to discharge
anything to storm drains or to
store or deposit materials so as to

create a potential discharge to
storm drains.”
Landscape/Outdoor Pesticide Us State that final landscape plans will accomplish all of the following.
• Preserve existing native trees,
shrubs, and ground cover to the
maximum extent possible.
• Design landscaping to minimize
irrigation and runoff, to promote
surface infiltration where
appropriate, and to minimize the
use of fertilizers and pesticides that
can contribute to
stormwater pollution.
• Where landscaped areas are used
to retain or detain stormwater,
specify plants that are tolerant to
saturated soil conditions.
• Consider using pest-resistant
plants, especially adjacent to
hardscape. To insure successful
establishment, select plants
appropriate to site soils, slopes,
climate, sun, wind,
rain, land use, air movement

• Maintain landscaping using
minimum or no pesticides.
• See applicable operational BMPs
in “What you should know for….

Landscape and Gardening” at
http://rcflood.org/stormwater/.
• Provide IPM information to new
owners, lessees and operators

Roofing, gutters and trim • Avoid roofing, gutters, and trim made of copper or other
unprotected metals that may
leach into runoff.

• See applicable operational BMPs
in “Guidelines for Maintaining
Your Swimming Pool, Jacuzzi and
Garden Fountain” at
http://rcflood.org/stormwater

- 25 -

Section H: Construction Plan Checklist
Populate Table H.1 below to assist the plan checker in an expeditious review of your project. The first two columns will contain information that was prepared in previous steps, while the last column will be populated with the corresponding plan sheets. This table is to be completed with the submittal of your final Project-Specific WQMP.

Table H.1 Construction Plan Cross-reference
BMP No. or
ID
BMP Identifier and
Description
Corresponding Plan Sheet(s) BMP Location (Lat/Long)
INFIL INFILTRATION BASIN CONCEPTUAL GRADE PLAN SHEE T 1 33°88’76” North 117°27’43” West

Note that the updated table — or Construction Plan WQMP Checklist — is only a reference tool to facilitate
an easy comparison of the construction plans to you r Project-Specific WQMP. Co-Permittee staff can advise you regarding the process required to propose changes to the approved Project-Specific WQMP.

- 26 -

Section I: Operation, Maintenance and Funding
The Copermittee will periodically verify that Stormwater BMPs on your site are maintained and continue to operate as designed. To make this possible, your Copermittee will require that you include in Appendix 9 of this Project-Specific WQMP:

1. A means to finance and implement facility maintenan ce in perpetuity, including replacement cost.

2. Acceptance of responsibility for maintenance from t he time the BMPs are constructed until responsibility for operation and maintenance is legally transferred. A warranty covering a period following construction may also be required.

3. An outline of general maintenance requirements for the Stormwater BMPs you have selected.

4. Figures delineating and designating pervious and im pervious areas, location, and type of Stormwater BMP, and tables of pervious and impervio us areas served by each facility. Geo- locating the BMPs using a coordinate system of latitude and longitude is recommended to help facilitate a future statewide database system.

5. A separate list and location of self-retaining areas or areas addressed by LID Principles that do not require specialized O&M or inspections but will require typical landscape maintenance as noted in Chapter 5, pages 85-86, in the WQMP Guidance. Include a brief description of typical landscape maintenance for these areas.

Your local Co-Permittee will also require that you prepare and submit a detailed Stormwater BMP Operation and Maintenance Plan that sets forth a maintenance schedule for each of the Stormwater BMPs built on your site. An agreement assigning responsi bility for maintenance and providing for inspection s and certification may also be required.

Details of these requirements and instructions for preparing a Stormwater BMP Operation and Maintenance Plan are in Chapter 5 of the WQMP Guidance Document.

Maintenance Mechanism: Insert text here.

Will the proposed BMPs be maintained by a Home Owne rs’ Association (HOA) or Property Owners Association (POA)?
Y N

Include your Operation and Maintenance Plan and Maintenance Mechanism in Appendix 9. Additionally, include all pertinent forms of educational material s for those personnel that will be maintaining the proposed BMPs within this Project-Specific WQMP in Appendix 10. - 27 -

Appendix 1: Maps and Site Plans
Location Map, WQMP Site Plan and Receiving Waters Map

THOMAS BROS. MAP PS 744 SR.ID 6-3

VICINITY MAP
----====:::::§~S:~<ifi15= -
SEC. 24 T.3S. R.6H
RIVERSIDE COUNTY FLOODCONTROL AND WATERCONSERVATION DISTRICTIsohyetal Mapfor the 85th Percentile24 hour Storm EventJuly 2011Rain Gage Locations Santa Ana River Reach 3
Ô
Ô
Ô
Ô
Ô
Ô
T
Ô
Ô
Reach 1b
Day Canyon Creek
Lake Mathews
Mockingbird Reservoir
Lake Evans
Lake Norconian
Prado Basin Management Zone
Santa Ana River Reach 3
Day Canyon Cre
Aliso Creek
Anza Park
Drain
San Antonio Creek
Chino Creek Reach 2
Chino CreekReach 1B
Chino Creek
Reach 1A
Temescal Creek
Reach 2
Temescal Creek Reach 2
Temescal Creek Reach 1a
Santa Ana River
Reach 3
Santa Ana River Reach 2
Santa Ana River
Reach 2
Mill Creek(Prado Area)
Cucamong
Cucamonga Creek
Reach 1
Teq(Sy
ch 2
Santa Ana River Reach 3
Aliso Creek
Cucamonga Creek Reach 1
Santa Ana River Reach 4
Chino Creek Reach 1B
d Canyon Creek
Sunnyslope Channel
180702030804
180702030605
180702031001
180702030706
180702030606
180702030705
180702030703
180702030603
180702030803
180702030902
180702030702
180702030802
180702030604
180702030704
180702031002
180701060505
180702030901 180702030604
I 15
CHINO

MISSION

ONTARIO
EUCLID

RIVERSIDE

MAGNOLIA

VAN BUREN
6TH
EDISON
GROVE

CAJALCO

LA SIERRA
MAIN

ARLINGTON
5TH

ARCHIBALD
RIVER

VICTORIA
PINE
TYLER
JURUPA
END

SCHAEFER
HAVEN
CORONA
RAMONA

CHINO VALLEY

CENTRAL

PHILADELPHIA

PHILLIPS
PEYTON

LIMONITE

INDIANA

LINCOLN
BAIN
PEDLEY
PALM

BELLEGRAVE

ETIWANDA

MOUNTAIN
CHASE

EL SOBRANTE
8TH
SIERRA
WELLS
GRAND
HAMNER
HOLE
4TH

CHINO HILLS
ADAMS
RIMPAU
10TH

BROCKTON

JACKSON
MONROE

LA PALMA

RAILROAD
CEDAR
TROTH
CHERRY

PIPELINE

SERRANO
PIERCE

RUBIDOUX
DEWEY
CITRUS

RIVERSIDE FWY

EL PRADO
STATE HWY 241
STATE HWY 60
UPPER

MCALLISTER
MARKET
STATE HWY 71

CORYDON

GREEN RIVER
GALENA

FULLERTON

WASHINGTON
BEACH
7TH

JEFFERSON
NORCO

MADISON

MILLIKEN

MERRILL

ARMSTRONG

PROMENADE
MARY

WEIR CANYON
BORDER

CLOVERDALE

VINEYARD

CAMINO REAL

BON VIEW
HOLMES

MOCKINGBIRD CANYON
WALKER
MAPLE

PALISADES
BEECH

SOQUEL CANYON
3RD

COLORADO
VALLEY
TAYLOR

AGUA MANSA

HELLMAN

MULBERRY
CRESTA

EUCALYPTUS

AVIATION

CARBON CANYON

YORBA LINDA

CALIFORNIA
2ND

RIVERVIEW

CLEVELAND
AVON

CHANDLER
GRANT
YUMA
2ND
JURUPA
STATE HWY 60

BON VIEW

CENTRAL

MISSION
6TH
HAMNER

LIMONITE
STATE HWY 241

ONTARIO
North
East
South
West
Home

PROJECT SITE

N ------------- ------------------
IN THE C.ITY OP RIVERSIDE, C,OUNTY OP RIVERSIDE, STATE OP C.ALIPORNIA TENTATIVE TRACT 38Ci21

BHP MAP---
-------------------------------------------------
--t-+- -i'i~ - - - - ---------------------
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LANDSCAPE AREAS
C3: 22,881 SF
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DMA
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C,I
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TOTAL
0 40
I M F
20 NAME

EXISTING

INFILTRATION
BASIN
HOMES

STREETS

LANDSCAPING
80 SC.ALE, I " = 40'
DMA I
SURPAC.E TYPE AREA (SP)
SELF-TREATING 2<1,400
NATURAL A SOIL 3,614
ROOF/LANDSCAPE 132,538 60% IMPERVIOUS
ASPHALT /WNCRETE 65,141
ORNAMENTAL 111 ,23<1 LANDSCAPING
341,<1<12
120
160
THOMAS BROS. MAP PG 144 GRID G-3

ENGINEER

ADKAN ENGINEERS
681<1 AIRPORT DRIVE
RIVERSIDE, CA <12504
TELEPHONE, (<151) 688-024 1
LGAGLIA@ADKAN,WM

ASSESSORS PARC-EL NUMBERS
136-220-016
LEGEND
.. DRAINAGE FL0"'6

DMA BOUNDARY
#~
<,i,
~
'll-
""'
' ,""'
7~ Q
VICINllY MAP
SEC. 24 T.3S . R.6N

OIAINER

LA SIERRA VICTORIA DEVELOPMENT LLG
1<1215 WILD MUSTANG COURT
APPLE VALLEY, GA 92301
APPLIC.ANT

WARMINGTON RESIDENTIAL
3090 PULLMAN ST
COSTA MESA, CA <12626

CONTACT, MATTHEW ESQUIVEL
EMA IL, MESOUIVEL@IAIARMINGTONGROUP,COM

AC ACRES

CATCH BASIN

CUBIC FEET PER SECOND
DRAINAGE AREA PROP. MAJOR CONTOUR

PROP, MINOR WNTOUR
CB
CFS
DA
DMA
EX,
PROP.

SF

DRAINAGE MANAGEMENT AREA

EXISTING

PROPOSED
========= PROP. STORM DRAIN
---, ---
~--~I HOMESITES
PROP. WATER
PROP,SE!<,ER

LANDSCAPE

STREETS

SELF-TREATING AREA
TYPIC.AL BASIN 5Ec.TION
SCALE: I 11 == 10'

SQUARE FEET
a'"tl ·. Ii

ENGINEERS
CivH Engineering • Surveying • Planning
6879 Airport Drive, Riverside, CA 92504
Tel:(951) 688--0241 • Fax:(951) 688--0599
- 28 -

Appendix 2: Construction Plans
Grading and Drainage Plans

WWWWWWWWWWWSSSSSSSSSSSSSSWSSSS

- 29 -

Appendix 3: Soils Information
Geotechnical Study and Other Infiltration Testing Data

ENGINEERS + GEOLOGISTS + ENVIRONMENTAL SCIENTISTS

Offices Strategically Positioned Throughout Southern California

RIVERSIDE COUNTY OFFICE
40880 County Center Drive, Suite M, Temecula, CA 92591
T: 951.600.9271 F: 951.719.1499
For more information visit us online at www.petra-inc.com

December 14, 2023
J.N. 23-341

WARMINGTON RESIDENTIAL
3090 Pullman Street
Costa Mesa, California 92626

Attention: Mr. Bret Ilich

Subject: Feasibility/Due-Diligence Desktop Geotechnical Review, Proposed 48 Lot Residential Project, Assessor’s Parcel Number 136-220-016, 7.9-Acre Site at SEC of Victoria and La Sierra Avenues, City of Riverside, Riverside County California

Dear Mr. Ilich

In accordance with your request, Petra Geosciences, Inc. (Petra) is providing this desktop feasibility/due- diligence geotechnical review for proposed 48-lot development in the city of Riverside, California. This report presents our findings and professional opinions with respect to the geotechnical feasibility of the proposed development, geotechnical constraints that should be taken into consideration during development of the site, and potential mitigation measures to bring the site to compliance from a geotechnical engineering viewpoint.

It must be emphasized that that t his desktop revi ew report is intended as a feasibility -level geotechnical assessment only and is based solely on a review of the referenced geotechnical literature, a site reconnaissance and updated engineering analysis . As such, t he contents of this report are not suitable for submittal to regulatory agencies, nor should the findings or conclusions provided herein be relied upon for earthwork, quantity calculation or procedure, or final structural engineering design. It should be further noted that this geotechnical evaluation does not necessarily address soil contamination or other environmental issues affecting the property.

SITE GENERAL OVERVIEW

The project site is essentially square-shaped and approximately 8.8-acres in size, of which 7.9 acres are proposed for development. The site is situated southeasterly of Victoria Avenue, southwesterly of Millsweet Place and northeasterly of La Sierra Avenue. Existing residences are located to the southeast and the site is currently utilized as an orange grove with the exception of the eastern quadrant that appears to have been more recently developed as a park or recreation feature. Site access is at a driveway at the end of Millsweet Place, although a locked gate is present off Victoria Avenue.

WARMINGTON RESIDENTIAL December 14, 2023
SEC Victoria and La Sierra Avenues / Riverside J.N. 23-341

DUE DILIGENCE ASSESSMENT

Geotechnical Literature Review and Site Reconnaissance

We have reviewed the e xisting geotechnical report, code update letter and supporting data for subject property by Soil Exploration Company , Inc. (SEC, 2014, 2019 ), as well as available published and unpublished geologic maps, data and reports, online aerial imagery and historic phots. We also performed a recent site reconnaissance to observe the surface conditions.

FINDINGS

Proposed Development

The current proposed development concept, Plan Option 3g by KTGY Architecture, will consist of 48 residential lots, a water quality basin and in -tract streets. A new site entrance will be constructed off La Sierra Avenue and Millsweet Place will be improved. The exiting orange grove along Victoria Avenue will remain as a 100-foot wide easement along with a trail . Other ancillary site improvements are expected to consist of underground utility lines (sewer, water, storm drain and dry utilities), perimeter masonry block screen walls, concrete sidewalks and landscaping. No grading plans are currently available; therefore, the preliminary grading quantities are currently unknown. Based on the low gradient of the site, significant fill slopes, cut slopes, nor retaining walls are currently anticipated.

Aerial Photograph Review

Based on aerial photographs reviewed, the subject site appears to have been utilized as an orange grove since at least 1931. Victoria and La Sierra Avenues were also present since that time and the surrounding properties were developed for residential use during the 1980’s. The grove operations have continued from at least 1931 to the present time with the exception of the southeasterly quadrant of the site. During 2002, portions of the grove in this local area was cleared and some localized construction appeared to be taking place by 2004. By 2007 the park and/or recreation facilities included an asphalt-paved driveway and several sheds had been constructed. This area appears to no longer be in use, with the exception of parking for contractor vehicles/trailers.

Site Reconnaissance

A representative of Petra performed a site reconnaissance and photo documentation on December 4, 2023.

Current access is via a n asphalt driveway off Millsweet Place near the southeastern corner and a locked gate is also present at Victoria Avenue. Wire and/or chain link fencing surrounds the site. The majority of WARMINGTON RESIDENTIAL December 14, 2023
SEC Victoria and La Sierra Avenues / Riverside J.N. 23-341

the site is covered by an active orange grove with other miscellaneous mature trees located in other areas, with the exception of the southeasterly quadrant which has been partially improved with a n asphalt driveway, a few sheds and miscellaneous playground -related equipment. These recreation facilities no longer appear to be in use; however, several contractor trailers and vehicles were currently parked within the site. A windmill structure is pres ent near the center of the site along with overhead power poles for electricity. Overhead power lines are also located along the southwestern property line with La Sierra Avenue.

Underground irrigation lines are present throughout the property and althou gh not observed, a water well may also be present. Two electric vaults were observed at the south corner and storm drain facilities are located at the north corner. The southeastern property edge appears to have undergone some minor grading, as evidenced by a noteworthy break in grade, and is clear of vegetation that may be related to an easement.

In addition to the various trees, site vegetation consists of a variable growth of weeds, grasses and shrubs, and miscellaneous debris was randomly observed on the surface of the site. The site descends at relatively low grading to the northwest.

Literature Review

As noted, Petra has reviewed the preliminary geotechnical report and code update letter by Soil Exploration Company, Inc. for the subject property, as well as geologic and geotechnical maps and data it the nearby area. The most pertinent geotechnical findings made from reviewing the report are paraphrased herein with any commentary/discussion by Petra in parenthesis and italics.

SEC Geotechnical Investigation and Update Letter (2014, 2019)

• The field investigation included 4 hollow-stem auger borings to depths ranging from 15 to 25 feet and performing 3 infiltration tests at a depth of 2 feet. (Petra: Due to limited access from the existing grove, the borings are primarily located in the middle portion of the site. The boring location map and logs are included as Appendix A herein for reference.)

• In general, the site is underlain by alluvial soils consisting of silty sand, sandy silt and si lty clay. The soils are loose near the surface and become dense to very dense and stiff below. Bedrock was encountered at depths of 15 to 20 feet. (Petra: Based on the 4 borings logs, the alluvial soils are loose to at least 10 feet in depth and mainly consist of silty sand soil type. No consolidation or collapse tests were performed in the loose alluvium.)

• Basic laboratory testing was performed for natural moisture content and dry density and sieve analysis.

Based on observation of the soils, the expansio n potential of near-surface soils is expected to be very low (Petra: One sand equivalent test was performed in addition to two sieve tests. No tests were performed for soil expansion or corrosion potentials. Based on the lab data, site soils have appreciable fines content and soil expansion could also be in the low range.) WARMINGTON RESIDENTIAL December 14, 2023
SEC Victoria and La Sierra Avenues / Riverside J.N. 23-341

• No groundwater was encountered in the borings. Historic groundwater is indicated to be at a depth of 10± feet and a well in the vicinity of the site indicated a depth to groundwater was 4.7 feet in 1974. (Petra: One boring was advanced to the maximum explored depth of 25 feet in January of 2014 did not encounter groundwater.)

• The site in an area of potential l iquefaction, however considering the depth to bedrock at 15 and 20 feet, the potential for liquefaction at the site is low. The potential for seismically induced dynamic settlement would be mitigated by overexcavation and recompaction of near surface sandy soils. (Petra:

Based on current standards of practice, we h ave performed a supplemental liquefaction/dynamic settlement as described further below.)

• The grading areas should be cleared of all vegetation, irrigation lines, roots, debris and deleterious materials which should be hauled offsite. Subsequent to site clearance and debris removal, the building areas should be overexcavated to a depth of at least 4 feet below ground or proposed grade, whichever is deeper, to expose underlying firm soils. Locally deeper overexcavation should not be precluded to expose competent soils. All foundations should be provided with at least 3 feet of compacted fill mat below the bottom of the footings. After overexcavation the exposed soils should be further scarified to a depth of at least 12 inches, watered and recompacted to at least 90 percent of the maximum dry density. (Petra: Based on the data in the borings logs, the alluvial silty sand soils appear to be loose to about 10 feet below ground surface. Based on a lack of geotechnical engineering test data, w e recommend a minimum removal or overexcavation depth of 6 to 7 feet below existing grades, as well as processing the exposed removal bottom in-place at least one foot in depth. Alternatively, additional exploratory borings and laboratory testing may be performed to confirm t hese preliminary recommendation depths.)

• The use of shallow spread footings is feasible for proposed structures. The expansion potential of the onsite sandy soils is anticipated to be very low, however this should be verified subsequent to completion of s ite preparation. The soluble sulfate content of the foundation soils should also be determined subsequent to complete of grading. (Petra: Based on the boring logs and reported lab data, site soils have appreciable fines content and soil expansion could als o be in the low range. We also recommend corrosion screening laboratory testing for presence of sulfates, chlorides and corrosion to metallic elements.)

• Three 8-inch diameter and two-feet deep test holes were excavated, and the soils were classified as silty sand. The field tests indicated an infiltration rate of 2.8, 4.5 and 17.9 inches per hour with no factor of safety applied. (Petra: SEC test IT-1 is in the vicinity of the proposed water quality basin which had a test rate of 2.8 inches/hour at a depth of 2 feet below grade. Depending on the depth of the proposed basin, additional field infiltration testing may be warranted.)

• The 2019 letter proved updated seismic parameters related to the 2016 CBC. (Petra: We have provided updated seismic design parameters for the current 2022 CBC as included in Appendix B herein.)

Local Area Geology and Soil Conditions

The subject property is situated on the medial portion of a broad alluvial fan descending at a moderate gradient northwesterly from the nearby El Sobrante mountain just to the south. The general area is underlain predominantly by young surficial alluvial deposits further underlain by dense older alluvial fan deposits.

WARMINGTON RESIDENTIAL December 14, 2023
SEC Victoria and La Sierra Avenues / Riverside J.N. 23-341

Topsoil and Artificial Fill – A presumed topsoil horizon and/or localized surficial artificial fill mantels the site to an anticipated depth of approximately 1 or 2 feet across the surface of the property. These materials generally consist of dry and very loose silty sand with organic material.

Younger Alluvium – Recent or young alluvium appears to be present beneath the topsoil horizon and these alluvial soils mainly consist of dry to moist, loose to medium dense, silty sands and occasional sandy silt.

These soils appear to be loose to a depth of approximately 10 feet.

Older Alluvium – Older alluvium appears to be present beneath the upper young alluvium at depths of approximately 10 to 15 feet below surface grades. These soils mainly consist of moist, firm to stiff, sandy silts and sandy clays.

Granitic Bedrock – Bedrock, mostly likely weathered granite, were encountered within 3 of the borings at depths of 15, 18.5 and 20 feet below surface grades. The upper 5 feet of the bedrock was readily excavated with the B-61 mobile hollow-stem auger drill utilized. Blow counts indicated medium dense to very dense conditions.

Groundwater

Groundwater levels in the nearby area have been reported to range from approximately 4.7 to 10± feet below surface grades in 1974 and on historic high groundwater maps respectively. Groundwater was not encountered within the borings advanced to a maximum depth of 25 feet below grade during January 2014 exploration. Free groundwater is not expected to be encountered during remedial grading at th e present time.

Compressible Soils

Based on our field observations and the data on the SCE borings logs, the existing soils including all topsoils and the upper portions of low-density alluvial deposits, are deemed to be potentially compressible. As such, these materials are considered unsuitable for support of proposed fills, structures, pavement or other improvements and should be removed to expose the underlying competent alluvium or alluvial fan deposits.

The removal soils may be subsequently placed as engineered (compacted) fill. The recommended remedial removal of natural alluvial soils us estimated to be at depths of approximately 6 to 7 feet below the existing ground surface along with processing the exposed removal bottom to a depth of one foot in-place. Localized areas of deeper excavation/removal of unsuitable soils could be necessary based on field observations during the course of grading and contingencies for such deeper should be planned considering past use within the site.

WARMINGTON RESIDENTIAL December 14, 2023
SEC Victoria and La Sierra Avenues / Riverside J.N. 23-341

Strong Ground Motions

The site is located in a seismically active area of southern California and will likely be subjected to very strong seismic-related ground shaking during the anticipated life span of the project. Structures within the site should therefore be designed and constructed to resist the effects of strong ground motion in accordance with the provisions of the 2022 California Building Code (2022 CBC).

Updated Liquefaction/Dynamic Settlement Potential

General
Based on a review of the Riverside County Land Informa tion System the site is mapped as having a moderate to high potential for liquefaction. Accordingly, Petra has performed an updated liquefaction analyses using the data provided in SEC, 2014 report to determine the liquefaction settlement potential in accordance with 2022 CBC requirements within the site.

Seismically Induced Settlement
Petra has reanalyzed the boring data with respect to potential for liquefaction and dry sand settlement within the site development. The analysis was performed following the guidelines contained in Special Publication 117A published by the California Geological Survey (1997, Revised 2008) and those in the 2022 California Building Code ( 2022 CBC). Considering the sandy nature of some of the onsite deposits, seismically induced settlement within the site is calculated to be on the order of 1 to 1 ½ inches across the site.

Based on our calculations, the differential settlement between various locations within the site is not expected to exceed 1 inch in 40 feet, which is considered well within tolerable limits for seismic differential settlement.

PRELIMINARY CONCLUSIONS AND RECOMMENDATIONS

Based on our recent reconnaissance and review of existing preliminary SCE report and data, development of the subject project site is considered feasible from a geotechnical engineering standpoint . It is recommended that the following geotechnical issues be considered by the Client during this due diligence period.

Primary Geotechnical Issues

Our professional opinion, from a geotechnical engineering viewpoint, regarding various aspects of the site existing conditions and the proposed development is presented within this letter report . The following WARMINGTON RESIDENTIAL December 14, 2023
SEC Victoria and La Sierra Avenues / Riverside J.N. 23-341

presents the salient features of our due diligence assessment that we recommend being considered for future site development.

• Rough Grading Plan Review and/or Updated Geotechnical Design Report: The city of Riverside may request a geotechnical update report during project approvals as well as review and signing of the future rough grading plans. The geotechnical report should include updated recommendations for site remedial and rough grading, post -grading improvements and preliminary building foundation d esign based on the current 20 22 California Building Code . Minor m odified recommendations could be warranted based on proposed slopes and/or retaining wall designs.

• Demolition of Improvements, Clearing and Grubbing : All existing trees and vegetation, and existing site improvements, such as power lines, a windmill structure, foundations or buried irrigation lines will need to be cleared or demolished and removed from the site. Other buried utility lines could be present within or along the b oundaries of the site. All other dumped debris and/or other deleterious materials found within the site will also require clearing and hauling offsite. Based on the past site usage, we further recommend that the grading contractor provide a dedicated crew to removing a ll trees roots, irrigation pipes and /or debris encountered during grading and fill operations.

• Removal of Unsuitable Soil Materials: The existing topsoil and upper portions of young alluvium will require removal and replacement as compacted fill. Based on Petra’s review of the existing boring data , we recommend an the upper 6 to 7 feet of existing soils should be removed to competent alluvial soils and replaced as compacted fill , however this should also be confirmed during grad ing by in -situ density testing of the removal bottoms, exhibiting a minimum of 85 percent relative compaction. Deeper removals are always possible depending on the exposed natural soils, and contingencies should be considered as with any large grading operation.

• Suitability of Onsite Soils for Fill : Onsite soils are considered suitable for use in engineering fill provided they are free of organics/roots or other deleterious materials. The shallow subsurface sandy soils may be in a dry condition to a depth of several feet and pre-watering of the site is highly recommended prior to site grading. As noted above, based on the historical site usage, the grading contractor should provide a dedicated crew to removing all organic s, tree roots, debris or other deleterious materials encountered during remedial grading and fill placement operations.

• Importing of Fill: Preliminary grading calculations should account for remedial alluvial removal and overexcavation depths, as well as for soil shrinkage when recompacted as fill. Based on the loose alluvial soils, shrinkage when replaced as compacted fill could be on the order of 15± percent, however that is a qualitative estimate and not based on any calculations. In the event imported soil material is needed to complete the project, all potential import source(s) should be evaluated at least one week prior to confirm that non-expansive, low corrosive soils that are free of deleterious materials or environmental contaminants will be imported.

• Liquefaction and Dynamic Settlement Potential: Based on Riverside County hazard maps, the site is located in a high zone for liquefac tion potential most likely due to historic high groundwater depths many decades ago . Based on the report and analysis by SEC liquefaction settlement was considered low due the presence of hard bedrock at 15 to 20 feet below the surface.

Based on our updated analysis, the potential for seismically induced settlement is on the order of 1 to 1½ inches under the unlikely scenario of high groundwater level of 5 feet below ground surface.

WARMINGTON RESIDENTIAL December 14, 2023
SEC Victoria and La Sierra Avenues / Riverside J.N. 23-341

• Soil Expansion and Corrosion Potential and Building Foundation Design : Local area soils are expected to have a very low expansion potential; however, low expansive soils could potentially be encountered during site grading. Supplemental sampling and testing of site soils for expansion and corrosion is recommended during the next phase of geotechnical report submittals.

• Foundation Design : The seismic and foundation design recommendations for the residential buildings should be provided in accordance with the current 2022 California Building Code (2022 CBC). Conventional foundations are feasible, and Appendix B contains preliminary foundation design based on the assumed future very low expansion as-graded soil conditions. Modifications may be warranted depending on the soil types placed at finish pad grades follow site grading.

• Infiltration Design: SEC reported infiltration rates of 2.8, 4.5 and 17.9 inches/hour at a test depth of 2 foot below grade within the site. Depending on the proposed infiltration ba sin depths, additional testing may be needed.

• Preliminary Pavement Design: Based on the observed soil types, moderate R-values are expected which will allow for a City of Riverside minimum pavement design presumably 4 inches of asphalt over 6 inches of base material for the interior streets. Final pavement design should be performed at the completion of street rough grading with final R-value testing.

REPORT LIMITATIONS

This report is based on the existing observed surficial conditions and the geotechnical document review for the subject site . The conclusions and opinions contained in this report are based on the results of the described geotechnical evaluations, primarily the 4 borings performed near the center of the site , very limited laboratory testing and our professional judgment. This report has been prepared consistent with that level of care being provided by other professionals providing similar services at the same locale and in the same time period. The contents of this report are professional opinions and as such, are not to be considered a guaranty or warranty.

This report should be reviewed and updated after a period of one year or if the site ownership or project concept changes from that described herein. This report has not been prepared for use by parties or projects other than those named or described herein. This repo rt may not contain sufficient information for other parties or other purposes.

WARMINGTON RESIDENTIAL December 14, 2023
SEC Victoria and La Sierra Avenues / Riverside J.N. 23-341

This opportunity to be of service is sincerely appreciated. If you have any additional questions or concerns, please feel free contact this office.

Respectfully submitted,
PETRA GEOSCIENCES, INC.

12/14/23
Douglass Johnston Siamak Jafroudi, PhD
Senior Associate Geologist Senior Principal Engineer
CEG 2477 GE 2024

DJ/SJ/kb

Attachments: References
Appendix A – SEC Exploration Map and Boring Logs
Appendix B – Tentative Preliminary Foundation Design Recommendations and Seismic Parameters

W:\2020-2025\2023\300\23-341\Reports\23-341 100 Due Diligence Report.docx

WARMINGTON RESIDENTIAL December 14, 2023
SEC Victoria and La Sierra Avenues / Riverside J.N. 23-341

REFERENCES

California Department of Water Resources, 2023, Water Data Library, accessed December, http://www.water.ca.gov/waterdatalibrary/groundwater/

California Geologic Survey, 202 3, Earthquake Zones of Required Investigation, Riverside West Quadrangle, accessed December, https://maps.conservation.ca.gov/cgs/EQZApp/app/

County of Riverside, 2022, Map My County System, version 11.5, accessed December, https://gis.countyofriverside.us/Html5Viewer/?viewer=MMC_Public

Google Earth™ 2023, by Google Earth, Inc., http://www.google.com/earth/index.html, accessed December.

ktgy Architecture + Planning, 2023, Conceptual Site Plan, Option 3g, dated October 3.

Morton, D. M. and Cox, B. F., 2001, Geologic Map of the Riverside West 7.5’ Quadrangle, Riverside County, California, Version 1.0, U.S.G.S. Open-File Report 01-451.

Soil Exploration Company, 2014, Preliminary Geotechnical Investigation/Liquefaction Evaluation/ Infiltration Tests Report, Proposed 8.8± Acre, 14 Lot Residential Subdivision, SEC of Victoria Avenue and La Sierra Avenue (APN 136 -220-016), City of Riverside, Califo rnia; prepared for Adkan Engineers, dated January 24.

_____, 2019, California Building Code (CBC) 2016 Seismic Update, Proposed 8.8±Acre, 14 Lot Residential Subdivision, SEC Victoria Avenue and La Sierra Avenue, City of Riverside, California, prepared for West Coast Hotels Group, LLC, dated December 16.

UC Santa Barbara Library, 2023, accessed December, http://mil.library.ucsb.edu/ap_indexes/FrameFinder/

APPENDIX A

SEC EXPLORATION MAP AND BORING LOGS

___ _./
, ,
''

GEOTECHNICAL BORING LOGS
Date: January 17, 2014
Drilling Company:. ___ W~D-'-1 ___ _
Hole Diameter- 8" Drive Weight· 140 lbs Drop: 30"
Drill Hole No .. _--=B'"""---1 _
Project No .. _ __,1.::.3..:..:16""'7-'-0=--1.___
Type of Rig:._---'B"""-'""'6..,_1 __ _
Elevation· 816±
DEPTH TYPE SAMPL BLOWS DRY MOISTURE SOIL GEOTECHNICAL DESCRIPTION (feet) OFTEST ETEST PER DENSITY (%) CLASSIFICATION LOGGED BY: GL 61NCH (%) uses SAMPLED BY:~ 1 SM SIL TY SAND: Light brown, fine to coarse grained, dry, Alluvium medium dense
2 3
Dry, medium dense, micaceous
4 4/8/10 108.4 3.4 % Passing No. 200 Sieve = 43
SE= 18
5 6
X
3/4/4 - - Slightly moist, loose
7 8
9 10
11 [X
3/6/4 - - Medium dense
12 13
14 15
16 [X
7/9/11 - - ML SANDY SILT: Light brown, slightly moist, stiff 17 18
19 20
21 [X
SM SILTY SAND: Light brown, fine to coarse grained, very Bedrock 15/37/50 - - dense 22 23
Very dense
24 TOT AL DEPTH = 25 FEET
[X

NO GROUNDWATER
19/39/50
NO CAVING 25

BORING BACKFILLED
Soil Exoloration Co .. Inc.

GEOTECHNICAL BORING LOGS
Drill Hole No. B-2
Date: January 17, 2014
Drilling Company: __ --'W'--'-=D_,_I ___ _
Hole Diameter- 8" Drive WeiQht· 140 lbs Drop· 30" .

Project No .. _ __,1=3..:..:16"-'7-'-0""1'--_
Type of Rig:. _ __;B:::..-..:6...:..1 __ _
Elevation· 818 5±
DEPTH TYPE SAMP BLOWS DRY MOISTURE SOIL GEOTECHNICAL DESCRIPTION (feet) OF LE PER DENSITY (%) CLASSIFICATION LOGGED BY: _fil_ TEST TEST SINCH (%) uses SAMPLED BY: GL 1 SM SIL TY SAND: Light brown, fine to medium grained, Alluvium slightly moist, loose, micaceous
2 3
[X
2/2/2 - - Loose 4
SE =29
5 6 113.3 13.1 ML SANDY SILT: Light brown, moist, loose, micaceous 3/4/4 % Passing No. 200 Sieve = 59
7 8
9 10
11 [><
2/3/3 - - Loose
12 13
14 CL-ML SILTY CLAY: Light brown, moist, stiff
[X
7/9/13 - -15
16 17 TOT AL DEPTH = 15 FEET

NO GROUNDWATER
18 NO CAVING

BORING BACKFILLED
19 20
21 22
23 24
25 Soil Exoloration Co .. Inc.

GEOTECHNICAL BORING LOGS
Drill Hole No. 8-3
Date: January 17. 2014
Drilling Company: ___ W:...:..::Dc.:..I ___ _
Hole Diameter- 8" Drive Weiaht· 140 lbs Droo· 30" .

Project No. _ __,_1 ::::.31.!.::6~7_,-0:c.!1'----
Type of Rig:, _ __,B=<---""6..,_1 __ _
Elevation· 822 5±
DEPTH TYPE SAMPL BLOWS DRY MOISTURE SOIL GEOTECHNICAL DESCRIPTION (feet) OFTEST ETEST PER DENSITY (%) CLASSIFICATION LOGGED BY: _§!,_ 61NCH 1%1 uses SAMPLED BY: GL 1 SM SILTY SAND: Light brown, fine to medium grained, Alluvium dry, loose
2 3
4 5
6 [X
3/4/4 - -
7 8
9 10
11 [X
5/6/7 - - ML SANDY SILT: Light brown, moist, stiff
12 13
14 15
16 Bedrock
[X
7/9/13 - - SM SIL TY SAND: Light gray, weathered, medium dense 17 18
19 20 [X
9/17/22 - -
21 22 TOT AL DEPTH = 20 FEET

NO GROUNDWATER
23 NO CAVING

BORING BACKFILLED
24 25
Soil Exoloration Co .. Inc.

GEOTECHNICAL BORING LOGS
Drill Hole No. B-4
Date: January 17, 2014
Drilling Company: ___ W:....:..::D..,_I ___ _
Hole Diameter· 8
11 Drive Weiqht· 140 lbs Drop· 30"
Project No .. _-"1=3...:.;16::..:7---'-0"-1.___
Type of Rig:._---'B"'--'""'6-'-1 __ _
Elevation- 824±
DEPTH TYPE SAMPL BLOWS DRY MOISTURE SOIL GEOTECHNICAL DESCRIPTION (feet) OFTEST ETEST PER DENSITY (%) CLASSIFICATION LOGGED BY: _@1__ 61NCH (%) uses SAMPLED BY: GL
1 SM SIL TY SAND: Light brown, fine to medium grained, Alluvium slightly moist, loose
2 3
4 5
6 [X
3/4/5 - - Loose
7 8
9 10
11 [X
5/5/5 - - Medium dense
12 13
14 15
16 [X
5/8/11 - - ML SANDY SILT: Light brown, slightly moist, stiff 17 18
19 [><
SIL TY SAND: Light brown, fine to coarse grained,
Bedrock 27/33/39 - - SM very dense 20
21 22 TOT AL DEPTH = 20 FEET

NO GROUNDWATER
23 NO CAVING

BORING BACKFILLED
24 25
Soil Exoloration Co .. Inc.

APPENDIX B

TENTATIVE PRELIMINARY FOUNDATION DESIGN

RECOMMENDATIONS AND SEISMIC PARAMETERS

WARMINGTON RESIDENTIAL December 14, 2023
SEC Victoria and La Sierra Avenues / Riverside J.N. 23-341

Tentative Preliminary Foundation Design Recommendations

Foundation System

Based on the expectation that very low expansion potential soils will be present at finish pads grades following site grading, a conventional slab-on-ground foundation is recommended for the proposed residual buildings. This should be confirmed by additional testing at the completion of site grading.

Allowable Soil Bearing Capacities

Pad Footings
An allowable soil bearing capacity of 1,500 pounds per square foot may be utilized for design of isolated 24-inch-square footings founded at a minimum depth of 12 inches below the lowest adjacent final grade for pad footings that are not a part of the slab system and are used for support of such features as roof overhang, second -story decks, patio covers, etc. This value may be increased by 20 percent for each additional foot of depth and by 10 percent for each additional foot of width, to a maximum value of 2,500 pounds per square foot. The recommended allowable bearing value includes both dead and live loads, and may be increased by one-third for short duration wind and seismic forces.

Continuous Footings
An allowable soil bearing capacity of 1,500 pounds per square foot may be utilized for design of continuous footings founded at a minimum depth of 12 inches below the lowest adjacent final grade. This value may be increased by 20 percent for each addit ional foot of depth and by 10 percent for each additional foot of width, to a maximum value of 2,500 pounds per square foot. The recommended allowable bearing value includes both dead and live loads and may be increased by one -third for short duration wind and seismic forces.

For foundations to be located adjacent to property lines where complete removal and re -compaction of unsuitable surficial soil materials below the proposed foundations can be performed but the horizontal limits of remedial grading are restricted due to perimeter constraints, a maximum allowable bearing value of 1,200 pounds per square foot should be used. These conditions may affect foundations for retaining and landscape walls to be located along the tract boundaries if remedial gradi ng cannot encroach into the adjacent properties. The need for special foundation design for these structures should be evaluated during grading based on the actual limits of remedial removals achieved by the grading contractor.

WARMINGTON RESIDENTIAL December 14, 2023
SEC Victoria and La Sierra Avenues / Riverside J.N. 23-341

Estimated Footing Settlement

Based on the allowable bearing values provided above, total static settlement of the footings under the anticipated loads is expected to be less than ¾ inch. Differential settlement is expected to be less than ½ inch over a horizontal span of 30 feet. The majority of settlement is likely to take place as footing loads are applied or shortly thereafter.

Lateral Resistance

A passive earth pressure increasing at a rate of 250 pounds per square foot per foot of depth, to a maximum value of 2,500 pounds per square foot, may be used to determine lateral bearing resistance for footings. In addition, a coefficient of friction of 0.40 times the dead load forces may be used between concrete and the supporting soils to determine lateral sliding resistance.

Lateral bearing and lateral sliding resistance may be combined without reduction. In addition, an increase of one-third of the above values may be used when designing for short duration wind and seismic forces.

The above values are based on footings place d directly against compacted fill. In the case where footing sides are formed, all backfill placed against the footings should be compacted to at least 90 percent of maximum dry density.

For foundations to be located adjacent to tract boundaries where com plete removal and recompaction of unsuitable surficial soil materials below the proposed foundations can be performed but the horizontal limits of remedial grading are restricted due to perimeter constraints, a passive pressure of 150 pounds per square foot, per foot of depth, to a maximum value of 1,500 pounds per square foot, should be used to determine the lateral bearing.

Guidelines for Footings and Slabs on-Grade Design and Construction

Soils within the site are anticipated to exhibit expansion poten tial that is within the Very Low range (Expansion Index from 0 to 20). As indicated in Section 1803.5.3 of 2022 California Building Code (2022 CBC), these soils are considered non-expansive and, as such, the design of slabs on-grade is considered to be exempt from the procedures outlined in Sections 1808.6.2 of the 2022 CBC and may be performed using any method deemed rational and appropriate by the project structural engineer. However, the following minimum recommendations are presented herein for conditions where the project design team may require geotechnical engineering guidelines for design and construction of footings and slabs on-grade the project site.

WARMINGTON RESIDENTIAL December 14, 2023
SEC Victoria and La Sierra Avenues / Riverside J.N. 23-341

The design and construction guidelines that follow are based on the above soil conditions and may be considered for reducing the effects of variability in fabric, composition and, therefore, the detrimental behavior of the site soils such as excessive short - and long-term total and differential settlements. These guidelines have been developed on the b asis of the previous experience of this firm on projects with similar soil conditions. Although construction performed in accordance with these guidelines has been found to reduce post -construction movement and/or distress, they generally do not positively eliminate all potential effects of variability in soils characteristics and future settlement.

It should also be noted that the suggestions for dimension and reinforcement provided herein are performance-based and intended only as preliminary guidelines to achieve adequate performance under the anticipated soil conditions. However, they should not be construed as replacement for structural engineering analyses, experience and judgment. The project structural engineer, architect and/or civil engineer shoul d make appropriate adjustments to slab and footing dimensions, and reinforcement type, size and spacing to account for internal concrete forces (e.g., thermal, shrinkage and expansion), as well as external forces (e.g., applied loads) as deemed necessary. Consideration should also be given to minimum design criteria as dictated by local building code requirements.

Conventional Slabs on-Grade System

Given the very low expansion potential by onsite soils expected to be present at finish pad grades, we recommend that footings and floor slabs be designed and constructed in accordance with the following minimum criteria.

Footings

1. Exterior continuous footings supporting one- and two-story structures should be founded at a minimum depth of 12 inches below the lowest adjacent final grade, respectively. Interior continuous footings may be founded at a minimum depth of 10 inches below the top of the adjacent finish floor slabs.

2. In accordance with Table 1809.7 of 2022 CBC for light -frame construction, all cont inuous footings should have minimum widths of 12 inches for one - and two-story construction. We recommend all continuous footings should be reinforced with a minimum of two No. 4 bars, one top and one bottom.

3. A minimum 12 -inch-wide grade beam founded at t he same depth as adjacent footings should be provided across garage entrances or similar openings (such as large doors or bay windows). The grade beam should be reinforced with a similar manner as provided above.

WARMINGTON RESIDENTIAL December 14, 2023
SEC Victoria and La Sierra Avenues / Riverside J.N. 23-341

4. Interior isolated pad footings, if required, should be a minimum of 24 inches square and founded at a minimum depth of 12 inches below the bottoms of the adjacent floor slabs. Pad footings should be reinforced with No. 4 bars spaced a maximum of 18 inches on centers, both ways, placed near the bottoms of the footings.

5. Exterior isolated pad footings intended for support of 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 No. 4 bars spaced a maximum of 18 inches on centers, both ways, placed near the bottoms of the footings. Exterior isolated pad footings may need to be connected to adjacent pad and/or continuous footings via tie beams at the discretion of the project structural engineer.

6. The minimum footing dimensions and reinforcement recommended herein may be modified (increased or decreased subject to the constraints of Chapter 18 of the 2022 CBC) b y the structural engineer responsible for foundation design based on his/her calculations, engineering experience and judgment.

Building Floor Slabs

1. Concrete floor slabs should be a minimum 4 inches thick and reinforced with No. 3 bars spaced a maximum of 24 inches on centers, both ways. Alternatively, the structural engineer may recommend the use of prefabricated welded wire mesh for slab reinforcement. For this condition, the welded wire mesh should be of sheet type (not rolled) and should cons ist of 6x6/W2.9xW2.9 (per the Wire Reinforcement Institute, WRI, designation) or stronger. All slab reinforcement should be supported on concrete chairs or brick to ensure the desired placement near mid -depth. Care should be exercised to prevent warping of the welded wire mesh between the chairs in order to ensure its placement at the desired mid-slab position.

2. Living area concrete floor slabs and areas to receive moisture sensitive floor covering should be underlain with a moisture vapor retarder consisti ng of a minimum 10 -mil-thick polyethylene or polyolefin membrane that meets the minimum requirements of ASTM E96 and ASTM E1745 for vapor retarders (such as Husky Yellow Guard®, Stego® Wrap, or equivalent). All laps within the membrane should be sealed, and at least 2 inches of clean sand should be placed over the membrane to promote uniform curing of the concrete. To reduce the potential for punctures, the membrane should be placed on a pad surface that has been graded smooth without any sharp protrusions. If a smooth surface cannot be achieved by grading, consideration should be given to lowering the pad finished grade an additional inch and then placing a 1 -inch-thick leveling course of sand across the pad surface prior to the placement of the membrane.

At the present time, some slab designers, geotechnical professionals and concrete experts view the sand layer below the slab (blotting sand) as a place for entrapment of excess moisture that could adversely impact moisture -sensitive floor coverings. As a p reventive measure, the potential for moisture intrusion into the concrete slab could be reduced if the concrete is placed directly on the vapor retarder. However, if this sand layer is omitted, appropriate curing methods must be implemented to ensure that the concrete slab cures uniformly. A qualified materials engineer with experience in slab design and construction should provide recommendations for alternative methods of curing and supervise the construction process to ensure uniform slab curing. Additional steps would also need to be taken to prevent puncturing of the vapor retarder during concrete placement.

3. Garage floor slabs should be a minimum 4 inches thick and reinforced in a similar manner as living area floor slabs. Garage slabs should also be p oured separately from adjacent wall footings with a WARMINGTON RESIDENTIAL December 14, 2023
SEC Victoria and La Sierra Avenues / Riverside J.N. 23-341

positive separation maintained using ¾ -inch-minimum felt expansion joint material. To control the propagation of shrinkage cracks, garage floor slabs should be quartered with weakened plane joints.

Consideration should be given to placement of a moisture vapor retarder below the garage slab, similar to that provided in Item 2 above, should the garage slab be overlain with moisture sensitive floor covering.

4. Presaturation of the subgrade below floor slabs will not be required; however, prior to placing concrete, the subgrade below all dwelling and garage floor slab areas should be thoroughly moistened to achieve a moisture content that is at least equal to or slightly greater than optimum moisture content. T his moisture content should penetrate to a minimum depth of 12 inches below the bottoms of the slabs.

5. The minimum dimensions and reinforcement recommended herein for building floor slabs may be modified (increased or decreased subject to the constraints o f Chapter 18 of the 2022 CBC) by the structural engineer responsible for foundation design based on his/her calculations, engineering experience and judgment.

SOIL

EXPLORATION
COMPAN.Y, INC.

Soil Engineering, Environmental Engineering, Materials Testing, Geology TO: Adkan Engineers
6879 Airport Dr.

Riverside, CA 92504
ATTENTION: Charissa Leach, P.E.

January 24, 2014
Project No. 13167-01
SUBJECT: Preliminary Geotechnical Investigation/Liquefaction Evaluation/Infiltration Tests Report, Proposed 8.8± Acre, 14 Lot Residential Subdivision, SEC of Victoria Avenue and La Sierra Avenue (APN 136-220-016), City of Riverside, California Introduction
In accordance with your authorization, Soil Exploration Co., Inc. has conducted a preliminary soil investigation and liquefaction analysis for the subject site (see Figure 1, Site Location Map). The accompanying report presents a summary of our findings, conclusions, recommendations and limitations of our work for the site development.

Scope of Work
• Review soils, geologic, seismic, groundwater data, maps and nearby site reports in our files. • Perform exploration of the site by means of three or four borings varying in depth from 15 to 25 feet below existing ground surface at readily accessible locations. • Field engineer for logging, sampling of select soils, observation of excavation resistance, record SPT blow counts, and water seepage (if any).
• Perform basic laboratory testing of select soil samples, including moisture, density, sieve analysis and expansion index.
• Perform three shallow infiltration tests at readily accessible locations. • Perform digitized search of known faults within a 50-mile radius of the site. • Determine CBC (2010) seismic parameters.
• Consult with project design engineer.
• Prepare a report of our findings, conclusions and recommendations for site preparation, including overexcavation/removal depth, liquefaction evaluation, allowable bearing value, foundation recommendations, footings/slab-on-grade depth/thickness, excavation characteristics, lateral earth pressures for retaining walls design, general earthwork and grading specifications, Cal/OSHA classification of soils, California Building Code (2010) seismic design coefficients and infiltration rate in inches/hour.

Site Conditions
The square shaped, 8.8± acre, flat site is located on the southeast corner of Victoria Avenue and La Sierra Avenue in the City of Riverside, California. Victoria Avenue is a paved road with AC curbs and La Sierra Avenue is a paved road with curbs, gutters and sidewalks. The site is bordered by a wire fence.

Access to the site is from southeast corner via a driveway leading from cleared area on Millsweet Place.

Vegetation throughout the site consists of small to medium size orange trees. 7535 Jurupa Ave., Unit C • Riverside, CA 92504 • Tel: (951) 688-7200 • Fax: (951) 688-7100 [email protected] • www.soilexp.com
SEC Victoria Ave. and La Sierra Ave.

Riverside, California
Project No. 13167-01
January 24, 2014
The approximate locations of some of the above features are shown on the Exploratory Boring and Infiltration Test Location Map (Plate 1 ).

Proposed Development
We understand that the 8.8± acre site is proposed for a 14 lot, single family residential development. The structures will be of wood frame construction with concrete floor slabs supported on prepared subgrade.

Based on the flat topography of the site, modest cut and fill grading and no significant cut or fill slopes are proposed.

Field Work
Four exploratory borings were drilled at the site on January 17, 2014, to a maximum depth of 25 feet below existing ground surface utilizing a B-61 mobile drill rig equipped with 8-inch diameter hollow stem auger.

Standard Penetration Test (SPT) blow counts were recorded at regular intervals and utilized in determining the compactness/consistency of the earth materials.

In general, these borings revealed that the site is underlain by alluvial soils consisting of silty sand, sandy silt and silty clay (USCS "SM", "ML" and "CL-ML"). The soils are loose near the surface and become dense to very dense and stiff below. Bedrock was encountered at depths of 15 to 20 feet in Borings B-1, B-3 and B-4. Based on USGS Geologic Map, the site is underlain with alluvial fan deposits (see Figure 2).

Envicom Plate VA shows the site is underlain with thin Pleistocene alluvium (10 feet to 200 feet thick).

Laboratory Testing
Basic laboratory tests were performed for select soil samples. The tests consisted primarily of natural moisture contents, dry densities and sieve analysis. Laboratory test results are presented in Appendix C and with Geotechnical Boring Logs (Appendix B).

Groundwater/Liquefaction
No groundwater was encountered in our exploratory borings at the time this work was performed. Based on referenced Carson & Matti map, the minimum historic groundwater is indicated to be at a depth of 10± feet. Well No. 679 in the vicinity of the site indicates the minimum depth to groundwater in 1974 was 4.7 feet.

Liquefaction occurs when loose, poorly graded, cohesionless soils are subject to ground shaking during an earthquake of large magnitude. The liquefaction potential is relatively higher when groundwater depths are less than 30 feet below ground surface. Based on referenced Envicom Map (Plate VA) and TLMA 1600-scale map dated September 26, 1997, the site is in an area of potential liquefaction.

Considering the depth to bedrock at 15 to 20 feet, the potential for liquefaction at the site is low.

Seismicity/Faulting
A computer search of all known Quarternary major faults within 50 miles of the site is presented in Appendix D. The computer search was performed by EQFAUL T (Version 3.00) software. Please note that it is probable that not all-active or potentially active faults in the region have been identified. Furthermore, seismic potential of the smaller and less notable faults is not sufficiently developed for assignment of maximum magnitudes and associated levels of ground shaking that might occur at the site due to these faults.

Soil Exploration Co., Inc. Page2
SEC Victoria Ave. and La Sierra Ave.

Riverside, California
Conclusions
Project No. 13167-01
January 24, 2014
• Vegetable matter, trees, roots, existing structures, old foundations, underground structures, old fills, buried utilities/irrigation lines, etc. and deleterious materials would require removal from the proposed improvement areas.
• Overexcavation and recompaction of surficial soils in building areas should be anticipated to provide adequate and uniform support for the proposed structures. • The earth materials encountered during our exploration can be excavated with normal grading equipment in good working condition.
• The onsite soils, exclusive of deleterious material, debris, roots, etc., may be used as compacted fill materials.
• Based on observation and soil classification, the expansion potential of the near-surface soils at the site is expected to be very low (El<20).
• The use of shallow foundations is feasible for the proposed light weight, residential construction. • Site is located approximately 8.5 and 8.6 miles from the Chino-Central Ave. (Elsinore) and Elsinore-Glen Ivy faults, respectively. The site is located in a region of generally high seismicity, as is all of Southern California. During its design life, the site is expected to experience moderate to strong ground motions from earthquakes on regional and/or nearby causative faults. • There is a 10 percent probability in 50 years that ground acceleration at the site will exceed 0.425g (see Appendix D).
• Based on referenced Envicom Map (Plate VA) and County of Riverside TLMA Geotechnical/Liquefaction Map, dated September 26, 1997, the site is in an area of potential liquefaction. Based on the bedrock at shallow depth and dense to very dense earth materials, the liquefaction potential at the site is low. • The potential for seismically induced dynamic settlement of the near surface sandy soils during earthquake would be mitigated by overexcavation and recompaction as recommended below in the report. • Based on Envicom Safety Element Map (Plate VB), the site is not in 100-year flood plain. However flood potential should be evaluated and considered in planning and design by civil engineering consultant. • Groundwater was not encountered during subsurface investigation. However our experience indicates that surface or near-surface groundwater conditions can develop in areas where groundwater conditions did not exist prior to site development, especially in areas where a substantial increase in surface water infiltration results from landscape irrigation. We therefore recommend that local landscape irrigation and landscape irrigation from surrounding areas be kept to the minimum necessary to maintain plant vigor and that any leaking pipes/sprinklers, etc. should be promptly repaired. We have no way of predicting depth to the groundwater or perched water, which may fluctuate with seasonal changes and from one year to the next.

Soil Exploration Co., Inc. Page3
SEC Victoria Ave. and La Sierra Ave.

Riverside, California
Project No. 13167-01
January 24, 2014
--1!1.----------------------------------------
Recommendations
Site Preparation/Overexcavation
All grading and backfills should be performed in accordance with the attached General Earthwork and Grading Specifications (Appendix E) except as modified in the text of this report.

The building/grading areas should be cleared of all vegetation, irrigation lines, roots, debris and deleterious materials which should be hauled offsite. Subsequent to site clearance and debris removal, the building area, extending at least 5 feet beyond building lines in plan (including any canopies/exterior footings), should be overexcavated to a depth of at least 4 feet below existing ground or proposed grade (whichever is deeper) to remove loose soils and roots and expose underlying firm soils. Locally deeper overexcavations should not be precluded specially to remove roots and expose competent soils. Vegetation roots should be traced and completely removed if encountered in bottom of the overexcavated areas. Root pickers may be required for this purpose. After any overexcavation, the exposed surfaces should be further scarified to a depth of at least 12-inches, watered and recompacted to at least 90 percent of the maximum dry density, as determined by ASTM D1557-09 Test Method, prior to placement of fill. All fills should be compacted to at least 90 percent of the maximum dry density.

Foundation Design
Following site preparation, the use of shallow spread footings supported on compacted fill is feasible for proposed structures. A net allowable bearing value of 1500 psf is recommended for foundations extending at least 12 inches into the compacted fill. This bearing value may be increased by one third for temporary (wind or seismic) loads. Reinforcement and other recommendations for residential structures are presented on Plate 2 and may be designed for very low expansion category. All foundations should be designed by a qualified structural engineer in accordance with the latest applicable building codes and structural considerations may govern. All foundations should be provided with at least 3 feet of compacted fill mat below bottom of footings. Please note foundation design is under the purview of structural engineer and structural engineer may have more stringent requirements.

Residential slabs-on-grade should be at least 4 inches thick, and should be reinforced with at least No. 3 bars at 18-inches on-center both ways, properly centered in mid-thickness of slabs. Slabs-on-grade should be underlain by a 10-mil Visqueen moisture barrier placed over two inches of clean rolled sand and overlain by two-inch layer of clean rolled sand to aid in concrete curing. Other additional recommendations for residential structures are presented on Plate 2.

Special Considerations
Slab-on-grade thickness and reinforcement should be evaluated by the structural engineer and designed in compliance with applicable codes. Excess soils generated from foundation excavations should not be placed on building pads and driveway without proper moisture and compaction. All slab subgrades should be verified to contain 1.2 times the soil optimum moisture content to a depth of 6 inches prior to placement of slab building materials. Moisture content should be tested in the field by the soil engineer. Slabs subgrade should be kept moist and the surface should not be allowed to desiccate.

The addition of fiber mesh in the concrete and careful control of water/cement ratios may lessen the potential for slab cracking. In hot or windy weather, the contractor must take appropriate curing precautions after the placement of concrete. The use of mechanically compacted/dense low slump concrete (not exceeding 4 inches at the time of placement) is recommended. We recommend that a slipsheet (or equivalent) be utilized if grouted tiles or other crack sensitive flooring (such as marble tiles) is planned directly on concrete slabs.

Soil Exploration Co., Inc. Page 4
SEC Victoria Ave. and La Sierra Ave.

Riverside, California
Retaining Walls/Lateral Earth Pressures
Project No. 13167-01
January 24, 2014
The following lateral earth pressures and soil parameters, in conjunction with the above-recommended bearing value of 1500 psf, may be used for design of retaining walls with free draining compacted backfills. If passive earth pressure and friction are combined to provide required resistance to lateral forces, the value of the passive pressure should be reduced to two-thirds the following recommendations.

Active Earth Pressure with level backfill (Pa)
At Rest Pressure (Po)
Passive Earth Pressure (Pp)
Horizontal Coefficient of Friction(µ)
Unit Soil Weight (y1)
35 psf (EFP), drained, yielding
50 psf (EFP), drained, non-yielding (part of building wall) 300 psf (EFP), drained, maximum of 3000 psf

0.30 120 pcf
We recommend drainage for retaining walls to be provided in accordance with Plate 3 of this report.

Maximum precautions should be taken when placing drainage materials and during backfilling. All wall backfills should be properly compacted to at least 90 percent relative compaction. Any waterproofing of the walls must be evaluated by the project architect and considered during planning and construction.

Expansion Index/Soluble Sulfates
Based on observation and soil classification, the expansion potential of the onsite sandy soils is anticipated to be very low (El<20). However, we recommend that expansion potential of the soils should be verified subsequent to completion of site preparation. Soluble sulfate content of the foundation soils should also be determined subsequent to completion of grading/prior to start of construction. Tentatively we recommend Type II cement and concrete slump not exceeding 4 inches at the time of placement. If critical, these should be further verified by your structural and/or a corrosion engineer.

Seismic Design
The site is approximately 8.5 and 8.6 miles from the Chino-Central Ave. (Elsinore) and Elsinore-Glen Ivy faults, respectively. Moderate to strong ground shaking can be expected and there is a 10 percent probability in 50 years that ground acceleration will exceed 0.425g at the site. A soil profile, site class D (stiff soil), has been considered for the site. The structural engineer should consider City/County local codes, California Building Code (CBC) 2010, seismic data presented in this report (Appendix D), the latest requirements of the Structural Engineers Association, and any other pertinent data in selecting design parameters.

Drainage
Positive drainage must be provided and maintained for the life of the project around the perimeter of the structure and all foundations toward streets or approved drainage devices to minimize water infiltrating into the underlying natural and engineered fill soils. In addition, finish subgrade adjacent to exterior footings should be sloped down and away to facilitate surface drainage. Roof drainage should be collected and directed away from foundations via nonerosive devices. Water, either natural or by irrigation, should not be permitted to pond or saturate the foundation soils.

Infiltration Test Procedure
Three 8-inch diameter, two-feet deep test holes (1-1, 1-2 and 1-3) were excavated at the randomly selected locations. The soil at the test locations was visually classified as silty sand (USCS "SM"). To mitigate any possible caving or sloughing of the test hole, an 8-inch diameter perforated canister was placed in the hole.

The testing was conducted after presoaking. Water level was adjusted to 6 inches above the bottom of the test hole. Consecutive measurements were taken at 30 minute intervals on test holes 1-1 and 1-2 and 10 minute intervals on test hole 1-3, until a stabilized rate of drop was obtained. The drop that occurred during the final reading was used for design purposes.

Soil Exploration Co., Inc. Page 5
SEC Victoria Ave. and La Sierra Ave.

Riverside, California
Project No. 13167-01
January 24, 2014
f
Infiltration Tests/Tabulated Results
Test No. Depth of Test Earth Material Infiltration Rate (feet) (in/hr)
1-1 2 Silty Sand ("SM") 2.82
1-2 2 Silty Sand ("SM") 4.56
1-3 2 Silty Sand ("SM") 17.9
We recommend that a suitable factor of safety should be applied to the rate in design of the system.

Cal/OSHA Classification/Trench Excavations/Backfills
In general Cal/OSHA classification of onsite soils appears to be Type B.

Temporary trench excavations deeper than 5 feet should be shored or sloped at 1: 1 or flatter in compliance with Cal/OSHA requirements. All utility trenches and wall backfills should be mechanically compacted to the minimum requirements of at least 90 percent relative compaction. No jetting, ponding, or flooding should be permitted within the building area or where trenches are in zone of influence of footing loads. Excavated material from footing trenches should not be placed in slab-on-grade and driveways areas unless properly compacted and tested.

Foundation Plan Review/Observations and Testing
The recommendations provided in this report are based on preliminary design information and subsurface conditions as interpreted from limited exploratory work. Our conclusions and recommendations should also be reviewed, verified during grading and construction, and revised as necessary. Soil Exploration Co., Inc. should review the foundation plan and observe and/or test at the following stages of construction:
• During all overexcavations, site preparation and grading. • Following footing excavations and prior to placement of footing materials. • During wetting of slab subgrade (1 .2 optimum moisture to a depth of 6 inches) and prior to placement of slab materials.
• During all trench backfills and pavements subgrade/base compaction. • When any unusual conditions are encountered.

Final Compaction Report
A final report of compaction control should be prepared subsequent to the completion of site preparation.

The report should include a summary of work performed, laboratory test results, and the results, locations and elevations of field density tests performed during rough grading.

Limitation of Investigation
Our investigation was performed using the degree of care and skill ordinarily exercised, under similar circumstances, by reputable Geotechnical Engineers practicing in this or similar locations. No other warranty, expressed or implied, is made as to the conclusions and professional advice included in this report. The field and laboratory test data are believed representative of the project site; however, soil conditions can vary significantly. As in most projects, conditions revealed during grading may be at variance with preliminary findings. If this condition occurs, the possible variations must be evaluated by the Project Geotechnical Engineer and adjusted as required or alternate design recommended. This report is issued with the understanding that it is the responsibility of the owner, or his representative, to ensure that the information and recommendations contained herein are brought to the attention of the architect and engineer for the project and incorporated into the plans, and the necessary steps are taken to see that the Soil Exploration Co., Inc. Page 6
SEC Victoria Ave. and La Sierra Ave.

Riverside, California
Project No. 13167-01
January 24, 2014
,.
contractor and subcontractor carry out such recommendations in the field. This firm does not practice or consult in the field of safety engineering. We do not direct the contractor's operations, and we cannot be responsible for other than our own personnel on the site; therefore, the safety of others is the responsibility of the contractor. The contractor should notify the owner if he considers any of the recommended actions presented herein to be unsafe. The findings of this report are valid as of the present date. However, changes in the conditions of a property can occur with the passage of time, whether they be due to natural processes or the works of man on this or adjacent properties. In additions, changes in applicable or appropriate standards may occur, whether they result from legislation or the broadening of knowledge.

This report was prepared for the client based on client's needs, directions and requirements at the time.

This report is not authorized for use by and is not to be relied upon by any party except the client with whom Soil Exploration Co., Inc. contracted for the work. Use of, or reliance on, this report by any other party is at that party's risk. Unauthorized use of or reliance on this report constitutes an agreement to defend and indemnify Soil Exploration Co., Inc. from and against any liability which may arise as a result of such use or reliance, regardless of any fault, negligence, or strict liability of Soil Exploration Co., Inc.

Closure
• arding this report, please do not hesitate to call our office. We appreciate th· ____ • e.

Distribution:

Attachments:
0;3417
~l?7t>
Figure 1
Figure 2
Plate 1
Plate2
Plate 3
Appendix A
Appendix B
Appendix C
Appendix D
Appendix E
Site Location Map
USGS Geologic Map
Exploratory Boring & Infiltration Test Location Map
Minimum Foundation and Slab Recommendations for Expansive Soils Retaining Wall Backfill and Subdrain Detail
References
Exploratory Boring Logs
Laboratory Test Results
Deterministic and CBC (2010) Seismic Parameters
General Earthwork and Grading Specifications
Soil Exploration Co., Inc. Page7
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Base Map: Geologic Map of the Riverside West/South ½ of Fontana Quadrangles, San Bernardino and Riverside County, California, Bv Thomas W. Dibblee, Jr., 2004.

LEGEND:

Qoa: Alluvial fan deposits of sand, minor gravel, tan to light reddish brown.

SEC of Victoria Avenue and La Sierra Avenue
(APN 136-220 -016)
City of Riverside , California
Soil Exploration Co., Inc.

Project No.: 13167-01
Date: January 24, 2014
Figure: 2
1,1
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1 11
11 I
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Minimum Footing
Width
Pad Footings
rLJEXPANSION INDEX (ASTM O 482Q)
t} •. ', • • . 0~20 . • .. : . • •
• • ->. fi·.l, . • VERYLOW ·EXPANSION{
Presoaking of (1 '. 2) times ~·p,timum moisture to a depth of at leasf 6" .,- r Living Areas &
Garage Slabs
Subgrade*
The Above Are Minimum Recommendations.

All Work Should Comply with Applicable/Governing Agency Codes and Requirements *Presoaking of living areas and garage slabs should be observed and tested by the project geotechnical engineer.

NOTES:

1. Depth of interior or exterior footings to be measured from lowest adjacent finish grade.

2. The base of the grade beam should be at the same elevation as that of the adjoining footings.

3. Living areas slabs may be tied to the footings as directed by the structural engineer.

4. We recommend the use of at least No. 3 bars at 18 inches on-center, each way, for all slabs.

5. 10-mil Visqueen sheeting welded at laps has proved successful. Equivalents are acceptable .

6. Garage slabs should be isolated from stem wall footings with a minimum 3/8" felt expansion joint.

7. Sand base should have a Sand Equivalent (SE) of 30 or greater (e.g., washed concrete sand).

Post-Tensioned Slabs
As an alternative to conventional foundations, building may be supported on post-tensioned slabs, to be designed by a structural engineer in consultation with the geotechnical consultant. In addition, a post-tensioned slab is also recommended for VERY HIGH expansion potential (Expansion Index greater than 130), if encountered. Post-tensioned slabs should have perimeter footings embedded a minimum of 12 inches below the adjacent grade. The slabs should be designed such that they can be deformed approximately 1-inch vertically over a width of 30 feet without distress in the event of shrinkage or swelling of the supporting soils.

Living area slabs should be underlain by a 10-mil Visqueen moisture barrier covered by a 2-inch layer of sand. Presoaking is recommended for post tensioned slabs: (1.2) x optimum to a depth of 12 inches, (1.3) x optimum to a depth of 18 inches, and (1.4) x optimum to a depth of 24 inches for LOW, MEDIUM, and HIGH expansion potential soils, respectively. LOW and MEDIUM expansive soil lots using conventional foundation should comply with 2010 CBC. For very high expansion potential (Expansion Index greater than 130), specific recommendations by the geotechnical consultant will be required. Placement of 4 inches of sand base is also suggested for post-tensioned slab systems. Unless stated in the attached report, for El=21-50 use Pl-25, and El=51-90 use Pl=35.

Minimum Foundation and Slab Recommendations
For Expansive Soils

ONE-AND TWO-STORY RESIDENTIAL BUILDINGS
m Soil Exploration Co. Inc.

H Plate: 2
OP'TlON N2: Pipe Surrounded
with ci ... 2 Material
With Proper Surface
Drainage
Waterproofing
Membrane
(Optional)
OPTION N1: Gravel Wrapped in
Filter Fabric
With Proper Surface
Drainage
1 ::'
Waterproofing T
Mombrane
{Optional)
OPTION N3: Geotextile Drain
With Proper Suifaee
Drainage •
Slope or·
level 6:t:'to 1:t' ~
Fabric Flap "-1-
Bohlnd Core T
Waterproofing
Membrane
{Optional)
--~-
Native
Backfill
Mlradtaln 6000•
J Drain 100, Hygrid
Crain 1, or equivalent
,.,...,__ __ ci ... 2 Filter y. to 11/a Inch Size Gravel Permeable Material Weep Hole Wrap~ in Filter Fabric Weep Hole 4-lnch Diameter Perlorated Pipe
Cla.M 2 Filter Permeable Material Grading
PM Caltrans .Specification,
Sieve Size Percent Pasaing
1• 100
31,4• 90-109
3/8' 40-100
No.4 25-40
No.a 18-33
No. 30 5-15
No. 50 0-7
No. 200 0-3
Level or ~
Slope ,.,,.~- ~
Proper Outlet Should be
Provided for Gravel Subdrain
{See Notes)
Levelor~,,,­
Slope _,,,./4f'"
•Miradrain 6000 or J Drain 100 for
non-waterproofed walls;
Miradrain 6200 or J Drain 200 for
completed waterproofed wali.
**Peel back the bottom fabric flap,
place pipe next to core,
wrap fabric around.pipe and
tuck behind core.

SUBDRAIN OPTIONS FOR CLEAN SAND BACKFILL
Wrth Proper Surface
Drainage
Waterproofing
Membrane ...........
(Optional)
...L
Clean sand backfill
having sand equivalent
of 30 or greater (can be
densified by water jetting)
-~E;:::'.~,.._ __ Subdrain Ootion S1 :
1 ft.3/ft. of ¼ to 1 ½' size
gravel wrapped in filter fabric
(see notes for outlet)
Subdrain Option S2:
4• diameter perforated pipe
surrounded with 1 ~ 3 /ft. of
Class 2 filter material per
Caltrans specifications a.s above
Subdrain Option S3:
rn~.,.;..:.+-- 4' diameter pertorated pipe
wrapped in filter fabric
• Pipe type should be ASTM 015Z7 Acrylonitrile Butediene Styrene (ABS) SDR:35 or ASTM 01785 Polyvinyl Chloride plastic (PVC), Schedule 40, Armco A2000 PVC, or approved equivalent Pipe should be installed with perforations down. • Filter fabric should be Mirafi 140N, 140NS, Supac 4NP, Amoco 4545, Trevira 1114, or approved equivalent. • All drains sho.uld have a gradient of 1 percent minimum. • Outlet portion for gravel subdrain should have a 4•-oiameter pipe with the perforated portion inserted into the gravel approximately 2· minimum and the nonperforated portion extending approximately 1' outside the gravel Proper sealing should be provided at the pipe insertion enabling water to run from the gravel portion into rather than outside the pipe. • Waterproofing membrane may be required for a specific retaining wall such as a stucco or basement wall. • Weephole should be 2' minimum diameter and provided at 25' minimum in length of wall. If exposure is permitted, weephole should be located at 3:::' above finished grade. H exposure is not permitted such as for a wall adjacent to a sidewalk/curb, a pipe under the sidewalk to discharge through the curb face or equillalerrt should be provided, or for a basement-type wall, a proper subdrain outlet system should be provided. Open vertical masonry joints 0,e., omit mortar from joints of first course above finished grade) at 32" maximum inteNals may be substituted for weepholes. Screening such as with a filter fabric should be provided for weepholes/open joints to prevent earth materials_fro.n:1. ~ntering the holes/join~------

RETAINING WALL BACKFILL

AND SUBDRAIN DETAIL
Soil Exploration Co. Inc.

Plate: 3

APPENDIX A
SEC Victoria Ave. and La Sierra Ave.

Riverside, California

REFERENCES
Project No. 13167-01
January 24, 2014
• Envicom, 1976, Seismic Hazards Map, City of Riverside Area, Plate VA, Dated September 1976. • Envicom, 1976, Safety Element Map, City of Riverside Area, Plate VB, Dated September 1976. • Department of the Interior, U.S. Geological Survey, Contour Map Showing Minimum Depth to Ground Water, Upper Santa Ana River Valley, California 1973-1979 (Sheet 2 of 2), By Scott E. Carson and Jonathan C. Matti, Dated 1985.
• U.S. Department of the Interior, U.S. Geological Survey, Geologic Map of the Riverside West Quadrangle, Riverside County, California, Dated 1994.
• TLMA, County of Riverside, Geotechnical/Liquefaction Map, Dated September 26, 1997. • CDMG, Maps of Known Active Fault Near-Source Zones in California and Adjacent Portions of Nevada, Dated February 1998.

Soil Exploration Co., Inc. Appendix A

APPENDIX B
-MAJOR DIVISIONS SYMBOLS
~

TYPICAL NAMES
-~·;:;B'·:. .. .. . ..

GW -: •.. . :-:- Well-graded gravels or gravel-sand mixtures, little or no fines . ... . .... . t.·•··· •.•.•.•.•. . Q) GRAVELS "'..:•:-:-:-:a -:-:-:-rn > · GP ;::t:::: :;: : : ;.;: ::: Poorly graded gravels or gravel-sand mixtures. little or no fines .9:! ..J U) 0 g (More than ½ of
fr1 . ti11J en N coarse fraction > No. GM Silty gravels, gravel-sand-silt mixtures 0 0 4 sieve size) w z
~ z V GC Clayey gravels, gravel-sand-clay mixturas
~ ·o .•.•.•.•.•.•.•.•.•.•.•. <n .. .. ... ....
(!) SW . ........... .

Well-graded sands or gravely sands, little or no fines
I 0 ::::::·:::::::::::::::::
w ~
. - .. ... .. ..
rn SANDS IO 000 00
0:: C:

SP oo ooooo Poorly graded sands or gravelly sands, little or no fines l1) <( £ ooO o o
0 ~ (More than ½ of .. . .. . . . . . .
(.) . . . ... ..
0 coarse fraction < No. SM .. . . . . . . . Silty sands, sand-salt mixtures ~
. . . ... . . .
4 sieve size) . . .
~
(~/?--_-:*~-:~:· /" SC Clayey sands, sand-clay mixtures ~ -8?-;,,-- .. . . · .· _ . . ·. /.

ML I I
Inorganic silts and very fine sands, rock flour, silty or clayey fine sands o · I or clayey silts with slight plasticity. 0
SILTS & CLAYS Cl) N
~
.J 0 Inorganic clays of low to medium plasticity, gravelly clays, sandy clays, 0 z CL silty clays, lean clays.

Cl) V LL< 50 . . . . . . ... .
0 . . .. . .. . .
·o.-.. OL . . . . . . . . . Organic silts and organic silty clays of low plasticity . w . . . . . . ?f
rn a, . . . .. . -> 0 Q)
< ~ -;;; MH Inorganic silts, caceous or diatonaceous fine sandy or silty soils, elastic a:: C silts (!) l1) SIL TS & CLAYS
-
I
£ Inorganic clays of medium to high plasticity, organic silty clays. -organic w CH z ~ silts u: 0 LL> 50
~ OH ~%' %~// Organic clays of medium to high plasticity. organic silty clays, organic / /),, /._, 0 silts
HIGHLY Pt Peat and other highly organic soils
ORGANIC SOILS ~

CLASSIFICATION CHART
(UNIFIED SOIL CLASSIFICATION SYSTEM)

RANGE OF GRAIN SIZES
CLASSIFICATION U.S. Standard Grain Size in
Sieve Size Millimeters
BOULDER ABOVE 12" ABOVE305
COBBLES 3" to 12· 305 to 76.2 60 /
GRAVEL 3" to No. 4 762 to 4.76
COARSE 3"TO ¾" 76.2 to 19.1
FINE ¾'"to No. 4 19.1 to4.76
SAND No. 4 to 200 4.76 to 0.074
COARSE No. 4 to 10 4.76 to 2.00
MEDIUM No. 10 to 40 2.00 to 0.420
>< UJ 50 Cl
?f 40
>-I- 30 c3
~ 20 Cl)
C i/ H
/
/ CH

CL / & ,,
FINE No. 40 to 200 0.420 to 0.074
SILT & CLAY BELOW No. BELOW0.074 200
< 10 ..J
Cl. 7
4 0
V MH
/
"' _1,,11 V
ML &OL
0 10 20 30 40 50 60 70 80 90 100

GRAIN SIZE CHART PLASTICITY CHART
NR No Recovery Classification in accordance with ASTM D2487 Description and visual observation in accordance with ASTM D2488 lt---it~....;..;=c-===-t--=...,;;;.=L..=.::::c..:c=--t--------1 All Sieve Sizes shown are US Standard Seepage SPT Refusal is defined as one of the following:
10 blows for no apparent displacement
50 blows for less than 6 inches advancement
100 blows for 6 to 18 inches advancement

GEOTECHNICAL BORING LOGS
Date: January 17, 2014
Drilling Company:. ___ W~D-'-1 ___ _
Hole Diameter- 8" Drive Weight· 140 lbs Drop: 30"
Drill Hole No .. _--=B'"""---1 _
Project No .. _ __,1.::.3..:..:16""'7-'-0=--1.___
Type of Rig:._---'B"""-'""'6..,_1 __ _
Elevation· 816±
DEPTH TYPE SAMPL BLOWS DRY MOISTURE SOIL GEOTECHNICAL DESCRIPTION (feet) OFTEST ETEST PER DENSITY (%) CLASSIFICATION LOGGED BY: GL 61NCH (%) uses SAMPLED BY:~ 1 SM SIL TY SAND: Light brown, fine to coarse grained, dry, Alluvium medium dense
2 3
Dry, medium dense, micaceous
4 4/8/10 108.4 3.4 % Passing No. 200 Sieve = 43
SE= 18
5 6
X
3/4/4 - - Slightly moist, loose
7 8
9 10
11 [X
3/6/4 - - Medium dense
12 13
14 15
16 [X
7/9/11 - - ML SANDY SILT: Light brown, slightly moist, stiff 17 18
19 20
21 [X
SM SILTY SAND: Light brown, fine to coarse grained, very Bedrock 15/37/50 - - dense 22 23
Very dense
24 TOT AL DEPTH = 25 FEET
[X

NO GROUNDWATER
19/39/50
NO CAVING 25

BORING BACKFILLED
Soil Exoloration Co .. Inc.

GEOTECHNICAL BORING LOGS
Drill Hole No. B-2
Date: January 17, 2014
Drilling Company: __ --'W'--'-=D_,_I ___ _
Hole Diameter- 8" Drive WeiQht· 140 lbs Drop· 30" .

Project No .. _ __,1=3..:..:16"-'7-'-0""1'--_
Type of Rig:. _ __;B:::..-..:6...:..1 __ _
Elevation· 818 5±
DEPTH TYPE SAMP BLOWS DRY MOISTURE SOIL GEOTECHNICAL DESCRIPTION (feet) OF LE PER DENSITY (%) CLASSIFICATION LOGGED BY: _fil_ TEST TEST SINCH (%) uses SAMPLED BY: GL 1 SM SIL TY SAND: Light brown, fine to medium grained, Alluvium slightly moist, loose, micaceous
2 3
[X
2/2/2 - - Loose 4
SE =29
5 6 113.3 13.1 ML SANDY SILT: Light brown, moist, loose, micaceous 3/4/4 % Passing No. 200 Sieve = 59
7 8
9 10
11 [><
2/3/3 - - Loose
12 13
14 CL-ML SILTY CLAY: Light brown, moist, stiff
[X
7/9/13 - -15
16 17 TOT AL DEPTH = 15 FEET

NO GROUNDWATER
18 NO CAVING

BORING BACKFILLED
19 20
21 22
23 24
25 Soil Exoloration Co .. Inc.

GEOTECHNICAL BORING LOGS
Drill Hole No. 8-3
Date: January 17. 2014
Drilling Company: ___ W:...:..::Dc.:..I ___ _
Hole Diameter- 8" Drive Weiaht· 140 lbs Droo· 30" .

Project No. _ __,_1 ::::.31.!.::6~7_,-0:c.!1'----
Type of Rig:, _ __,B=<---""6..,_1 __ _
Elevation· 822 5±
DEPTH TYPE SAMPL BLOWS DRY MOISTURE SOIL GEOTECHNICAL DESCRIPTION (feet) OFTEST ETEST PER DENSITY (%) CLASSIFICATION LOGGED BY: _§!,_ 61NCH 1%1 uses SAMPLED BY: GL 1 SM SILTY SAND: Light brown, fine to medium grained, Alluvium dry, loose
2 3
4 5
6 [X
3/4/4 - -
7 8
9 10
11 [X
5/6/7 - - ML SANDY SILT: Light brown, moist, stiff
12 13
14 15
16 Bedrock
[X
7/9/13 - - SM SIL TY SAND: Light gray, weathered, medium dense 17 18
19 20 [X
9/17/22 - -
21 22 TOT AL DEPTH = 20 FEET

NO GROUNDWATER
23 NO CAVING

BORING BACKFILLED
24 25
Soil Exoloration Co .. Inc.

GEOTECHNICAL BORING LOGS
Drill Hole No. B-4
Date: January 17, 2014
Drilling Company: ___ W:....:..::D..,_I ___ _
Hole Diameter· 8
11 Drive Weiqht· 140 lbs Drop· 30"
Project No .. _-"1=3...:.;16::..:7---'-0"-1.___
Type of Rig:._---'B"'--'""'6-'-1 __ _
Elevation- 824±
DEPTH TYPE SAMPL BLOWS DRY MOISTURE SOIL GEOTECHNICAL DESCRIPTION (feet) OFTEST ETEST PER DENSITY (%) CLASSIFICATION LOGGED BY: _@1__ 61NCH (%) uses SAMPLED BY: GL
1 SM SIL TY SAND: Light brown, fine to medium grained, Alluvium slightly moist, loose
2 3
4 5
6 [X
3/4/5 - - Loose
7 8
9 10
11 [X
5/5/5 - - Medium dense
12 13
14 15
16 [X
5/8/11 - - ML SANDY SILT: Light brown, slightly moist, stiff 17 18
19 [><
SIL TY SAND: Light brown, fine to coarse grained,
Bedrock 27/33/39 - - SM very dense 20
21 22 TOT AL DEPTH = 20 FEET

NO GROUNDWATER
23 NO CAVING

BORING BACKFILLED
24 25
Soil Exoloration Co .. Inc.

APPENDIX C
SEC Victoria Ave. and La Sierra Ave.

Riverside, California

LABORATORY TEST RESULTS
SEC of Victoria Avenue and La Sierra Avenue
City of Riverside , California
SIEVE B-1 @2.5' B-2@5'
SIZE % PASSING % PASSING
3/8" 100 -
No. 4 99.5 100
No. 8 98 98
No. 16 93 91
No. 30 86 83
No. 50 78 77
No. 100 65 69
No. 200 43 59

SIEVE ANALYSIS TEST DATA
B-1 (@ 2.5' B-2 (@. 2.5'
18 29

SAND EQUIVALENT TEST DATA
Soil Exploration Co., Inc.

Project No. 13167-01
January 24, 2014
Appendix C

APPENDIX D
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EQFAULT
Version 3.00
*
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*
*
*
***********************

DETERMINISTIC ESTIMATION OF

PEAK ACCELERATION FROM DIGITIZED FAULTS
JOB NUMBER: 13167-01
JOB NAME: Adkan Engineers
CALCULATION NAME: Test Run Analysis
FAULT-DATA-FILE NAME: CDMGFLTE.DAT
SITE COORDINATES:

SITE LATITUDE: 33.8875
SITE LONGITUDE: 117.4619
SEARCH RADIUS: 50 mi
DATE: 12-30-2013
ATTENUATION RELATION: 14) Campbell & Bozorgnia (1997 Rev.) - Alluvium UNCERTAINTY (M=Median, S=Sigma): S Number of Sigmas: 1.0 DISTANCE MEASURE: cdist
SCOND: 0
Basement _Depth: 5. 00 km Campbell SSR: 0

COMPUTE PEAK HORIZONTAL ACCELERATION
FAULT-DATA FILE USED: CDMGFLTE.DAT
MINIMUM DEPTH VALUE (km): 3.0

EQFAULT SUMMARY
Campbell SHR: 0

DETERMINISTIC SITE PARAMETERS
!ESTIMATED MAX. EARTHQUAKE EVENT
APPROXIMATE 1-------------------------------
ABBREVIATED DISTANCE I MAXIMUM I PEAK JEST. SITE
FAULT NAME mi ( km) !'EARTHQUAKE I SITE I INTENSITY
I I MAG. (Mw) I ACCEL. g IMOD.MERC.
-=-=====-=======================i==============i==========i==========i========= CHINO-CENTRAL AVE. (Elsinore) I 8.5( 13 . 6) I 6.7 I 0.501 I X ELSINORE-GLEN IVY I 8.6( 13.8) I 6.8 I 0.431 I X
WHITTIER 10.5( 16.9)1 6.8 I 0.366 I IX
SAN JACINTO-SAN BERNARDINO 15.1( 24.3) I 6.7 I 0.248 I IX SAN JACINTO-SAN JACINTO VALLEY 15.8 ( 25.4) I 6.9 I 0.270 I IX ELSINORE-TEMECULA 18.2( 29.3) I 6.8 I 0.221 I IX
SAN JOSE 21.0( 33.8) 6 . 5 I 0.171 I VIII
CUCAMONGA 21.9( 35.3) 7.0 I 0.221 I IX
SAN ANDREAS - Southern 23.7( 38.1) 7.4 I 0.255 I IX
SAN ANDREAS - San Bernardino 23.7( 38.1) 7.3 I 0.239 I IX SIERRA MADRE 23 . 7( 38.2) 7.0 I 0.203 I VIII
ELYSIAN PARK THRUST 23.7( 38.2) 6.7 I 0.168 I VIII
CLEGHORN 27.9( 44.9) 6.5 I 0.114 I VII
SAN ANDREAS - 1857 Rupture 29.6( 47.6) 7.8 I 0.268 I IX SAN ANDREAS - Mojave 29.6( 47.6) 7.1 I 0.167 I VIII
NORTH FRONTAL FAULT ZONE (West) I 30.1( 48.4) 7.0 I 0.155 I VIII COMPTON THRUST I 30.6( 49.3) 6.8 I 0.134 I VIII
NEWPORT-INGLEWOOD (Offshore) 1. 32.5( 52.3) 6.9 I 0.131 I VIII NEWPORT-INGLEWOOD (L.A.Basin) I 32 . 9( 53.0) I 6.9 I 0.129 I VIII SAN JACINTO-ANZA I 32.9( 53.0) I 7.2 I 0.160 I VIII
CLAMSHELL-SAWPIT I 34.7( 55.9 ) I 6 . 5 I 0.091 I VII
RAYMOND I 37.2( 59.8) I 6.5 I 0.083 I VII
VERDUGO I 42. 8 ( 68. 8) I 6. 7 I 0. 079 I VII
ELSINORE-JULIAN I 43 . 7( 70.3) I 7 . 1 I 0.109 I VII
PINTO MOUNTAIN_ I 44.1( 70.9) I 7.0 I 0.098 I VII
PALOS VERDES I 44.6( 71.7) I 7.1 I 0.106 I VII
NORTH FRONTAL FAULT ZONE (East) I 44.7( 71.9) I 6 . 7 I 0.075 I VII HOLLYWOOD I 47.2( 76.0) I 6.4 I 0.054 I VI
HELENDA;LE - S. LOCKHARDT I 47.7 ( 76.7) I 7 . 1 I 0.097 I VII ************************************t****************************************** -END OF SEARCH- 29 FAULTS FOUND WITHIN THE SPECIFIED SEARCH RADIUS.

THE CHINO-CENTRAL AVE. (Elsinore) FAULT IS CLOSEST TO THE SITE. IT IS ABOUT 8.5 MILES (13.6 km) AWAY. LARGEST MAXIMUM-EARTHQUAKE SITE ACCELERATION: 0.5006 g -/-
***********************
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*

E Q F A U L T
Version 3.00
*
*
*
*
*
***********************

DETERMINISTIC ESTIMATION OF

PEAK ACCELERATION FROM DIGITIZED FAULTS
JOB NUMBER: 13167-01
JOB NAME: Adkan Engineers
CALCULATION NAME: Test Run Analysis
FAULT-DATA-FILE NAME: CDMGFLTE.DAT
SITE COORDINATES:

SITE LATITUDE: 33.8875
SITE LONGITUDE: 117.4619
SEARCH RADIUS: 50 mi
DATE: 12-30-2013
ATTENUATION RELATION: 14) Campbell & Bozorgnia (1997 Rev.) - Alluvium UNCERTAINTY (M=Median, S=Sigma): M Number of Sigmas: 0.0 DISTANCE MEASURE: cdist
SCOND: 0
Basement Depth: 5.00 km Campbell SSR: 0 Campbell SHR: 0

COMPUTE PEAK HORIZONTAL ACCELERATION
FAULT-DATA FILE USED: CDMGFLTE.DAT
MINIMUM DEPTH VALUE (km): 3.0

EQFAULT SUMMARY

DETERMINISTIC SITE PARAMETERS
I
I

ABBREVIATED I

FAULT NAME I
I
!ESTIMATED MAX. EARTHQUAKE EVENT
APPROXIMATE 1------------------------------­
DISTANCE I MAXIMUM I PEAK IEST. SITE
mi (km) IEARTHQUAKEI SITE !INTENSITY
I MAG. (Mw) I ACCEL. g IMOD.MERC.
================================!=== ===1==========1==========1========= CHINO-CENTRAL AVE. (Elsinore) I

ELSINORE-GLEN IVY I

WHITTIER I

SAN JACINTO-SAN BERNARDINO I

SAN JACINTO-SAN JACINTO VALLEY I

ELSINORE-TEMECULA I

SAN JOSE I

CUCAMONGA I
SAN ANDREAS - Southern I
SAN ANDREAS - San Bernardino I

SIERRA MADRE I

ELYSIAN PARK THRUST I

CLEGHORN I
SAN ANDREAS - 1857 Rupture I
SAN ANDREAS - Mojave I
NORTH FRONTAL FAULT ZONE (West) I

COMPTON THRUST I
NEWPORT-INGLEWOOD (Offshore) I
NEWPORT-INGLEWOOD (L.A.Basin) I

SAN JACINTO-ANZA I

CLAMSHELL-SAWPIT I

RAYMOND I

VERDUGO I

ELSINORE-JULIAN I

PINTO MOUNTAIN I

PALOS VERDES I
NORTH FRONTAL FAULJ ZONE (East) I

HOLLYWOOD I
HELENDALE - S. LOCKHARDT I

8. 5 (

8. 6 (

10.5(

15.1(

15.8(

18. 2 (

21. 0 (

21. 9 (

23. 7 (

23. 7 (

23. 7 (

23. 7 (

27. 9 (

29.6(

29.6(

30.1(

30.6(

32.5(

32.9(

32.9(

34. 7 (

37. 2 (

42.8(

43. 7 (
44 .1 (

44. 6 (

44. 7 (

47. 2 (

47. 7 (

13.6) I 6.7 I 0.339 I IX

13.8) I 6.8 I 0.292 I IX

16. 9 l I 6. 8 I 0. 2 4 8 I IX

24.3) I 6.7 I 0.161 I VIII

25.4) I 6.9 I 0.178 I VIII

29.3) I 6.8 I 0.142 I VIII

33.8) I 6.5 I 0.105 I VII

35.3) I 7.0 I 0.141 VIII

38.1)1 7.4 I 0.167 VIII

38.1) I 7.3 I 0.155 VIII

38.2) I 7.0 I 0.128 VIII

38. 2) I 6. 7 I O. 103 VII
4 4 . 9) I 6. 5 I O. 0 6 6 VI
4 7 . 6) I 7 . 8 I O . 177 VI II

47.6)1 7.1 I 0.102 VII

48.4) I 7.0 I 0.094 VII

49.3) I 6.8 I 0.079 VII

52.3) I 6.9 I 0.077 VII

53.0) I 6.9 I 0.075 VII

53.0) I 7.2 I 0.097 VII

55.9)1 6.5 I 0.052 VI

59.8) I 6.5 I 0.048 VI

68.8) I 6.7 I 0.046 VI
7 0. 3 l I 7. l I 0. 0 63 VI

70.9) I 7.0 I 0.057 VI

71. 7 l I 7. 1 I 0. 0 61 VI

71.9) I 6.7 I 0.043 VI

76.0) I 6.4 I 0.031 V

76.7)1 7.1 I 0.056 VI
******************************************************************************* -END OF SEARCH- 29 FAULTS FOUND WITHIN THE SPECIFIED SEARCH RADIUS.

THE CHINO-CENTRAL AVE. (Elsinore) FAULT IS CLOSEST TO THE SITE. IT IS ABOUT 8.5 MILES (13.6 km) AWAY. LARGEST MAXIMUM-EARTHQUAKE SITE ACCELERATION: 0.3390 g -r:1,. -
,,......._
~ 0 ..........
~
+-'
·--.0
ro
.0
0 s...

Cl.
(])
(.)
C:
ro
"O
(])
(])
. (.)
X
w

PROBABILITY OF EXCEEDANCE
CAMP. & BOZ. (1997 Rev.) AL 1
100
90 80
70 60
50 40
30 20
10 0

0.00 I • I 25 yrs
I ■ I
75 rs
I • I 50 yrs
I T I
100 rs

0.25 0.50 0. 75 1.00 1.25 1.50
Acceleration (Q)
SEC Victoria Ave. and La Sierra Ave.

RiveJside, California
2010 CBC-SEISMIC PARAMETERS
Mapped Spectral Response Acceleration Ss = 1.50
Site Coefficients (Class "D") Fa= 1.00
Maximum Considered Earthquake (MCE) SMs = 1.500 Spectral Response Acceleration Design Spectral Response Acceleration Sos= 1.000 Parameters Seismic Design Category
References:
• Earthquake.usgs.gov/research/hazmaps/design
D
Project No. 13167-01
January 24, 2014
S1 = 0.60
Fv = 1.50
SM1 = 0.900
S01 = 0.600
• 2010 California Building Code, California Code of Regulations, Title 24, Part 2, Volume 2 of 2, Section 1613, Earthquake Loads
Soil Exploration Co., Inc.

APPENDIX E

GENERAL EARTHWORK AND GRADING SPECIFICATIONS

1.0 GENERAL INTENT
These specifications present general procedures and requirements for grading and earthwork as shown on the approved grading plans, including preparation of areas to be filled, placement of fill, installations of subdrains, and excavations. The recommendations contained in the geotechnical report are a part of the earthwork and grading specifications and shall supersede the provisions contained hereinafter in the case of conflict.

Evaluations performed by the consultant during the course of grading may result in new recommendations which could supersede these specifications or the recommendations of the geotechnical report.

2.0 EARTHWORK OBSERVATIONS ANO TESTING
Prior to the commencement of grading, a qualified geotechnical consultant (soils engineer and engineering geologist, and their representatives) shall be employed for the purpose of observing earthwork procedures and testing the fills for conformance with the recommendations of the geotechnical report and these specifications. It will be necessary that the consultant provide adequate testing and observations so that he may determine that the work was accomplished as specified. It shall be the responsibility of the contractor to assist the consultant and keep him apprised of work schedules and changes so that he may schedule his personnel accordingly.

It shall be the sole responsibility of the contractor to provide adequate equipment and methods to accomplish the work in accordance with applicable grading codes or agency ordinances, these specifications and approved grading plans. If, in the opinion of the consultant, unsatisfactory conditions, such as questionable soil, poor moisture conditions, inadequate compaction, adverse weather, etc., are resulting in a quality of work less than required in these specifications, the consultant will be empowered to reject the work and recommend that construction be stopped until the unsatisfactory conditions are rectified.

Maximum dry density tests used to determine the degree of compaction will be performed in accordance with the American Society of Testing and Materials, test method ASTM D1557-09.

3.0 PREPARATION OF AREAS TO BE FILLED

3.1 Clearing and Grubbing
All brush, vegetation, and debris shall be removed or piled and otherwise disposed of.

3.2 Processing
The existing ground which is determined to be satisfactory for support of fill shall be scarified to a minimum depth of 6 inches. Existing ground which is not satisfactory shall be overexcavated as specified in the following section. Scarification shall continue until the soils are broken down and free of large clay lumps or clods and until the working surface is reasonably uniform and free of uneven features which would inhibit uniform compaction.

3.3 Overexcavation
Soft, dry, spongy, highly fractured or otherwise unsuitable ground, extending to such depth that surface processing cannot adequately improve the condition, shall be overexcavated down to firm ground, approved by the consultant.

3.4 Moisture Conditioning
Overexcavated and processed soils shall be watered, dried-back, blended, and/or mixed, as required to attain a uniform moisture content near optimum.

3.5 Recompaction
Overexcavation and processed soils which have been properly mixed and moisture-conditioned shall be recompacted to a minimum relative compaction of 90 percent.

Soil Exploration Co., Inc. Appendix E-1

3.6 Benching
Where fills are to be placed on ground with slopes steeper than 5:1 (horizontal : vertical), the ground shall be stepped or benched.

The lowest bench shall be a minimum of 15 feet wide, shall be at least 2 feet deep, shall expose firm materials, and shall be approved by the consultant. Other benches shall be excavated in firm materials for a minimum width of 4 feet. Ground sloping flatter than 5:1 (horizontal : vertical) shall be benched or otherwise overexcavated when considered necessary by the consultant.

3. 7 Approval
All areas to receive fill, including processed areas, removal areas and toe-of-fill benches shall be approved by the consultant prior to fill placement.

4.0 . FILL MATERIAL

4.1 General
Material to be placed as fill shall be free of organic matter and other deleterious substances, and shall be approved by the consultant.

Soils of poor gradation, expansion, or strength characteristics shall be placed in areas designated by consultant or shall be mixed with other soils to serve as satisfactory fill material.

4.2 Oversize
Oversize materials defined as rock, or other irreducible material with maximum dimension greater than 12 inches, shall not be buried or placed in fills, unless the location, materials, and disposal methods are specifically approved by the consultant. Oversize disposal operations shall be such that nesting of oversize material does not occur, and such that the oversize material is completely surrounded by compacted or densified fill. Oversize material shall not be placed within 10 feet vertically of finish grade or within the range of future utilities or underground construction, unless specifically approved by the consultant.

4.3 Import
If importing of fill material is required for grading, the import material shall meet the requirements of Section 4.1.

5.0 FILL PLACEMENT and COMPACTION

5.1 Fill Lifts
Approved fill material shall be placed in areas prepared to receive fill in near-horizontal layers not exceeding 6 inches in compacted thickness. The consultant may approve thicker lifts if testing indicates the grading procedures are such that adequate compaction is being achieved with lifts of greater thickness. Each layer shall be spread evenly and shall be thoroughly mixed during spreading to attain uniformity of material and moisture in each layer.

5.2 Fill Moisture
Fill layers at a moisture content less than optimum shall be watered and mixed, and wet fill layers shall be aerated by scarification or shall be blended with drier material. Moisture conditioning and mixing of fill layers shall continue until the fill material is at a uniform moisture content at or near optimum.

5.3 Compaction of Fill
After each layer has been evenly spread, moisture-conditioned, and mixed, it shall be uniformly compacted to not less than 90 percent of maximum dry density. Compaction equipment shall be adequately sized and shall be either specifically designed for soil compaction or of proven reliability, to efficiently achieve the specified degree of compaction.

Soil Exploration Co., Inc. Appendix E-2

5.4 Fill Slopes
Compacting of slopes shall be accomplished, in addition to nonnal compacting procedures, by backrolling of slopes with sheepsfoot rollers at frequent increments of 2 to 3 feet in fill elevation gain, or by other methods producing satisfactory results. At the completion of grading, the relative compaction of the slope out to the slope face shall be at least 90 percent.

5.5 Compaction Testing
Field-tests to check the fill moisture and degree of compaction will be perfonned by the consultant. The location and frequency of tests shall be at the consultant's discretion. In general, the tests will be taken at intervals not exceeding 2 feet in vertical rise and/or 1,000 cubic yards of embankment.

6.0 SUBDRAIN INSTALLATION
Subdrain systems, if required, shall be installed in approved ground to confonn to the approximate alignment and details shown on the plans or herein. The subdrain location or materials shall not be changed or modified without the approval of the consultant. The consultant, however, may recommend and upon approval, direct changes in subdrain line, grade or material. All subdrains should be surveyed for line and grade after installation and sufficient time shall be allowed for the surveys, prior to commencement of filling over the subdrain.

7.0 EXCAVATION
Excavations and cut slopes will be examined during grading. If directed by the consultant, further excavation or overexcavation and refilling of cut areas shall be performed, and/or remedial grading of cut slopes shall be perfonned. Where fill-over-cut slopes are to be graded, unless otherwise approved, the cut portion of the slope shall be made and approved by the consultant prior to placement of materials for construction of the fill portion of the slope.

8.0 TRENCH BACKFILLS
Trench excavations for utility pipes shall be backfilled under engineering supervision.

After the utility pipe has been laid, the space under and around the pipe shall be backfilled with clean sand or approved granular soil to a depth of at least one foot over the top of the pipe. The sand backfill shall be unifonnly jetted into place before the controlled backfill is placed over the sand.

The onsite materials, or other soils approved by the soil engineer, shall be watered and mixed as necessary prior to placement in lifts· over the sand backfill.

The controlled backfill shall be compacted to at least 90 percent of the maximum dry density as detennined by the ASTM D1557-09 test method.

Field density tests and inspection of the backfill procedures shall be made by the soil engineer during backfilling to see that proper moisture content and unifonn compaction is being maintained. The contractor shall provide test holes and exploratory pits as required by the soil engineer to enable sampling and testing.

Soil Exploration Co., Inc. Appendix E-3
..

TO·
SOIL

EXPLORATION
COMPANY , INC.

Soil Engineering , Environmental Engineering, Materials Testing, Geology December 16, 2019
Project No 13167-01
West Coast Hotels Group LLC
19215 Wild Mustang Ct.

Apple Valley, CA 92307
ATTENTION.

SUBJECT
Hitesh Patel
California Building Code (CBC) 2016 Seismic Update, Proposed 8.B±Acre, 14 Lot Residential Subdivision, SEC Victoria Avenue and La Sierra Avenue, City of Riverside, California
REFERENCES Soil Exploration Co., Inc , "Preliminary Geotechnical Investigation/Liquefaction Evaluation/Infiltration Tests Report, Proposed 8.8± Acre, 14 Lot Residential Subdivision, SEC of Victoria Avenue and La Sierra Avenue (APN 136-220-016), City of Riverside, California" Dated January 24, 2014 (Project No. 13167-01).

Introduction
As requested, we have prepared the following updated seismic parameters for the subject site.

CBC 2016 Seismic Parameters
The CBC (2016) seismic parameters for the site are tabulated below:
2016 CBC- SEISMIC PARAMETERS
Site Coordinates
Latitude I Lonaitude

33.8875 I -117.4619
Mapped Spectral Response Acceleration s. = 1.500 S1 = 0.600 Site Coefficients (Class "D") Fa= 1.00 Fv = 1.50
Maximum Considered Earthquake (MCE)
I SMs = 1.500 SM1 = 0.900 SDectral ResDonse Acceleration Design Spectral Response Acceleration Sos = 1.000 So, = 0.600 Parameters Seismic Design Category D
Peak Ground Accelerat ion (PGA) 0.514g
References ·
• Earthquake .usgs.gov/research/hazmaps/des1gn
• 2016 California Building Code, California Code of Regulations. Trtle 24, Part 2, Volume 2 of 2, Section 1613, Earthquake Loads
7535 Jurupa Ave., Unit C • Riverside, CA 92504 • Tel: (951) 688-7200 • Fax: (951) 688-7100 [email protected] • www.soilexp.com
Victoria Ave & La Sierra Ave.

Riverside , California
Foundation Plan ReviewlAdditional Observations and Testing Project No. 13167-01
December 16, 2019
Soil Exploration Co., Inc should review the foundation plans and observe andlor test at the following stages of construction:
• Dunng any additional grading or fill placement
• Following footings excavation and prior to placement of footing materials • During all utility trench backfills and street subgrade/base compaction. • Following wetting of slab subgrade (1.2.X optimum to a depth of at least 6") and prior to placement of slab materials.
• When any unusual conditions are encountered.

Limitation
Soil Exploration Co., Inc. has striven to perform our services within the limits prescribed by our client, and in a manner consistent with the usual thoroughness and competence of reputable soils engineers practicing under similar circumstances. No other representation, express or implied, and no warranty or guarantee is included or intended by virtue of the services performed or reports, opinion, documents, or otherwise supplied
Closure
If you should have any questions regarding this report, please do not hesitate to contact our office. We appreciate this opportuni to be of service.

Very truly yours,
Soil Exploration
Gene K. Luu, PE 53417
Project Engineer
Distribution: (1) Addressee ([email protected]) Attachments Figure 1 Site Location Map
Soil Exploration Co., Inc . Pagel
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- 30 -

Appendix 4: Historical Site Conditions
Phase I Environmental Site Assessment or Other Information on Past Site Use

- 31 -

Appendix 5: LID Infeasibility
LID Technical Infeasibility Analysis

- 32 -

Appendix 6: BMP Design Details
BMP Sizing, Design Details and other Supporting Documentation

Date
D85= 0.56 inches
DMA
Type/ID
DMA Area
(square feet)
Post-Project Surface
Type
Effective
Imperivous
Fraction, If
DMA
Runoff
Factor
DMA Areas x
Runoff Factor
Design
Storm
Depth (in)
Design Capture
Volume, VBMP
(cubic feet)
Proposed
Volume on
Plans (cubic
feet)
C1 132538 Roofs 1.00 0.89 118223.9
C2 65141 Concrete or Asphalt 1.00 0.89 58105.8
C3 111239 Ornamental
Landscaping 0.1 0.11 12287.2
B1 3674 Natural (A Soil) 0.03 0.06 229.8
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 312592 188846.7 0.56 8812.8 9177.5
Notes:

Total
85th Percentile, 24-hour Rainfall Depth,
from the Isohyetal Map in Handbook Appendix E
Insert additional rows if needed to accommodate all DMAs draining to the BMP Santa Ana Watershed - BMP Design Volume, VBMP
(Rev. 10-2011)
Legend:

Required Entries
Calculated Cells
(Note this worksheet shall only be used in conjunction with BMP designs from the LID BMP Design Handbook ) Company Name Adkan Engineers 1/31/2022
Designed by Israel Duque Case No
Company Project Number/Name Warmington- Tract 36713
BMP Identification
Drainage Management Area Tabulation
Design Rainfall Depth
BMP NAME / ID Inflitration basin
Must match Name/ID used on BMP Design Calculation Sheet Company Name: Date:

Designed by: County/City Case No.:

AT = 7.4 acres
b) Enter VBMP determined from Section 2.1 of this Handbook VBMP= 8,832 ft3 I = 2.85 in/hr
FS = 3
D1 = D1 = 5.7 ft
1 ft
e) Enter depth to historic high ground water (measured from top of basin) 15 ft 15 ft
D2 = 4.0 ft
DMAX = 4.0 ft
z = 2 :1
dB = 2.5 ft
AS = 3533 ft2
AD = 3,671 ft2
Volume = 44 ft3
Depth = 1 ft
Area = 44 ft2

36.0 in
Notes:
a) Tributary area (BMP subarea)
g) D2 is the smaller of:
d) Enter the depth of freeboard (at least 1 ft)
h) D
MAX is the smaller value of D1 and D2 but shall not exceed 5 feet Design Volume
a) Basin side slopes (no steeper than 4:1) Slope no steeper than 4:1 Maximum Depth
a) Infiltration rate
b) Factor of Safety (See Table 1, Appendix A: "Infiltration Testing" from this BMP Handbook)
c) Calculate D1
Basin Geometry
f) Enter depth to top of bedrock or impermeable layer (measured from top of basin) I (in/hr) x 72 hrs
12 (in/ft) x FS
Depth to groundwater - (10 ft + freeboard) and
Depth to impermeable layer - (5 ft + freeboard)
Calculated Cells
Adkan Engineers

ISRAEL DUQUE
Infiltration Basin - Design Procedure
(Rev. 03-2012)
BMP ID Legend: Required Entries
d) Proposed Design Surface Area
c) Minimum bottom surface area of basin (AS= VBMP/dB)
b) Proposed basin depth (excluding freeboard)
Forebay
c) Forebay surface area (minimum)
Width (W) =
b) Forebay depth (height of berm/splashwall. 1 foot min.) a) Forebay volume (minimum 0.5% VBMP)
d) Full height notch-type weir
- 33 -

Appendix 7: Hydromodification
Supporting Detail Relating to Hydrologic Conditions of Concern

Infiltration Basin Bottom Area (sf) 3674
Basin Top Area (sf) 4899
Depth of Basin (ft) 2.5
Open Basin Volume Provided (cf) 10716
Rock Storage depth (ft) 4.6
Rock Storage Volume (40% void) (cf) 6755
Total Flood Volume Stored 17472
Ex. 2-yr 24-hr Storm Volume (cf) 8233
Prop. 2-yr 24-hr Storm Volume (cf) 26528
Allowable 2-yr 24-hr Storm Volume
(mitigated to 110% of existing) (cf) 9056
Prop. 2-yr 24-hr Storm Volume (cf) 26528
Total Flood Volume Stored 17472
Remaining Storm Volume 9056
Basin Storage Volume Calculations
EX2YR24HR Page 1 of 9
U n i t H y d r o g r a p h A n a l y s i s
Copyright (c) CIVILCADD/CIVILDESIGN, 1989 - 2008, Version 8.1 Study date 02/22/24 File: EX2YR242.out
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ------------------------------------------------------------------------ Riverside County Synthetic Unit Hydrology Method
RCFC & WCD Manual date - April 1978
Program License Serial Number 5006
--------------------------------------------------------------------- English (in-lb) Input Units Used
English Rainfall Data (Inches) Input Values Used
English Units used in output format
--------------------------------------------------------------------- -------------------------------------------------------------------- Drainage Area = 7.00(Ac.) = 0.011 Sq. Mi.

Drainage Area for Depth-Area Areal Adjustment = 7.00(Ac.) = 0.011 Sq. Mi.

Length along longest watercourse = 596.00(Ft.)
Length along longest watercourse measured to centroid = 300.00(Ft.) Length along longest watercourse = 0.113 Mi.

Length along longest watercourse measured to centroid = 0.057 Mi.

Difference in elevation = 26.00(Ft.)
Slope along watercourse = 230.3356 Ft./Mi.

Average Manning's 'N' = 0.030
Lag time = 0.038 Hr.

Lag time = 2.26 Min.
25% of lag time = 0.56 Min.
40% of lag time = 0.90 Min.

Unit time = 5.00 Min.

Duration of storm = 24 Hour(s)
User Entered Base Flow = 0.00(CFS)
2 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

7.00 1.80 12.60
100 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

7.00 6.00 42.00
STORM EVENT (YEAR) = 2.00
Area Averaged 2-Year Rainfall = 1.800(In)
Area Averaged 100-Year Rainfall = 6.000(In)
Point rain (area averaged) = 1.800(In)
Areal adjustment factor = 100.00 %
Adjusted average point rain = 1.800(In)
Sub-Area Data:

Area(Ac.) Runoff Index Impervious %

7.000 72.00 0.100
Total Area Entered = 7.00(Ac.)
RI RI Infil. Rate Impervious Adj. Infil. Rate Area% F AMC2 AMC-1 (In/Hr) (Dec.%) (In/Hr) (Dec.) (In/Hr)

72.0 53.4 0.537 0.100 0.489 1.000 0.489 Sum (F) = 0.489
Area averaged mean soil loss (F) (In/Hr) = 0.489
Minimum soil loss rate ((In/Hr)) = 0.244
(for 24 hour storm duration)
Soil low loss rate (decimal) = 0.820
--------------------------------------------------------------------- U n i t H y d r o g r a p h
VALLEY S-Curve
-------------------------------------------------------------------- Unit Hydrograph Data
--------------------------------------------------------------------- Unit time period Time % of lag Distribution Unit Hydrograph (hrs) Graph % (CFS) EX2YR24HR Page 2 of 9
--------------------------------------------------------------------- 1 0.083 221.634 46.905 3.309 2 0.167 443.269 41.886 2.955 3 0.250 664.903 7.981 0.563 4 0.333 886.537 3.228 0.228 Sum = 100.000 Sum= 7.055
----------------------------------------------------------------------- The following loss rate calculations reflect use of the minimum calculated loss rate subtracted from the Storm Rain to produce the maximum Effective Rain value Unit Time Pattern Storm Rain Loss rate(In./Hr) Effective (Hr.) Percent (In/Hr) Max | Low (In/Hr) 1 0.08 0.07 0.014 ( 0.867) 0.012 0.003 2 0.17 0.07 0.014 ( 0.863) 0.012 0.003 3 0.25 0.07 0.014 ( 0.860) 0.012 0.003 4 0.33 0.10 0.022 ( 0.857) 0.018 0.004 5 0.42 0.10 0.022 ( 0.853) 0.018 0.004 6 0.50 0.10 0.022 ( 0.850) 0.018 0.004 7 0.58 0.10 0.022 ( 0.847) 0.018 0.004 8 0.67 0.10 0.022 ( 0.843) 0.018 0.004 9 0.75 0.10 0.022 ( 0.840) 0.018 0.004 10 0.83 0.13 0.029 ( 0.837) 0.024 0.005 11 0.92 0.13 0.029 ( 0.834) 0.024 0.005 12 1.00 0.13 0.029 ( 0.830) 0.024 0.005 13 1.08 0.10 0.022 ( 0.827) 0.018 0.004 14 1.17 0.10 0.022 ( 0.824) 0.018 0.004 15 1.25 0.10 0.022 ( 0.820) 0.018 0.004 16 1.33 0.10 0.022 ( 0.817) 0.018 0.004 17 1.42 0.10 0.022 ( 0.814) 0.018 0.004 18 1.50 0.10 0.022 ( 0.811) 0.018 0.004 19 1.58 0.10 0.022 ( 0.807) 0.018 0.004 20 1.67 0.10 0.022 ( 0.804) 0.018 0.004 21 1.75 0.10 0.022 ( 0.801) 0.018 0.004 22 1.83 0.13 0.029 ( 0.798) 0.024 0.005 23 1.92 0.13 0.029 ( 0.795) 0.024 0.005 24 2.00 0.13 0.029 ( 0.791) 0.024 0.005 25 2.08 0.13 0.029 ( 0.788) 0.024 0.005 26 2.17 0.13 0.029 ( 0.785) 0.024 0.005 27 2.25 0.13 0.029 ( 0.782) 0.024 0.005 28 2.33 0.13 0.029 ( 0.779) 0.024 0.005 29 2.42 0.13 0.029 ( 0.775) 0.024 0.005 30 2.50 0.13 0.029 ( 0.772) 0.024 0.005 31 2.58 0.17 0.036 ( 0.769) 0.030 0.006 32 2.67 0.17 0.036 ( 0.766) 0.030 0.006 33 2.75 0.17 0.036 ( 0.763) 0.030 0.006 34 2.83 0.17 0.036 ( 0.760) 0.030 0.006 35 2.92 0.17 0.036 ( 0.756) 0.030 0.006 36 3.00 0.17 0.036 ( 0.753) 0.030 0.006 37 3.08 0.17 0.036 ( 0.750) 0.030 0.006 38 3.17 0.17 0.036 ( 0.747) 0.030 0.006 39 3.25 0.17 0.036 ( 0.744) 0.030 0.006 40 3.33 0.17 0.036 ( 0.741) 0.030 0.006 41 3.42 0.17 0.036 ( 0.738) 0.030 0.006 42 3.50 0.17 0.036 ( 0.735) 0.030 0.006 43 3.58 0.17 0.036 ( 0.732) 0.030 0.006 44 3.67 0.17 0.036 ( 0.729) 0.030 0.006 45 3.75 0.17 0.036 ( 0.726) 0.030 0.006 46 3.83 0.20 0.043 ( 0.722) 0.035 0.008 47 3.92 0.20 0.043 ( 0.719) 0.035 0.008 48 4.00 0.20 0.043 ( 0.716) 0.035 0.008 49 4.08 0.20 0.043 ( 0.713) 0.035 0.008 50 4.17 0.20 0.043 ( 0.710) 0.035 0.008 51 4.25 0.20 0.043 ( 0.707) 0.035 0.008 52 4.33 0.23 0.050 ( 0.704) 0.041 0.009 53 4.42 0.23 0.050 ( 0.701) 0.041 0.009 54 4.50 0.23 0.050 ( 0.698) 0.041 0.009 55 4.58 0.23 0.050 ( 0.695) 0.041 0.009 56 4.67 0.23 0.050 ( 0.692) 0.041 0.009 57 4.75 0.23 0.050 ( 0.689) 0.041 0.009 58 4.83 0.27 0.058 ( 0.686) 0.047 0.010 59 4.92 0.27 0.058 ( 0.683) 0.047 0.010 60 5.00 0.27 0.058 ( 0.680) 0.047 0.010 61 5.08 0.20 0.043 ( 0.677) 0.035 0.008 62 5.17 0.20 0.043 ( 0.674) 0.035 0.008 63 5.25 0.20 0.043 ( 0.672) 0.035 0.008 64 5.33 0.23 0.050 ( 0.669) 0.041 0.009 65 5.42 0.23 0.050 ( 0.666) 0.041 0.009 66 5.50 0.23 0.050 ( 0.663) 0.041 0.009 67 5.58 0.27 0.058 ( 0.660) 0.047 0.010 68 5.67 0.27 0.058 ( 0.657) 0.047 0.010 69 5.75 0.27 0.058 ( 0.654) 0.047 0.010 70 5.83 0.27 0.058 ( 0.651) 0.047 0.010 71 5.92 0.27 0.058 ( 0.648) 0.047 0.010 72 6.00 0.27 0.058 ( 0.645) 0.047 0.010 EX2YR24HR Page 3 of 9
73 6.08 0.30 0.065 ( 0.643) 0.053 0.012 74 6.17 0.30 0.065 ( 0.640) 0.053 0.012 75 6.25 0.30 0.065 ( 0.637) 0.053 0.012 76 6.33 0.30 0.065 ( 0.634) 0.053 0.012 77 6.42 0.30 0.065 ( 0.631) 0.053 0.012 78 6.50 0.30 0.065 ( 0.628) 0.053 0.012 79 6.58 0.33 0.072 ( 0.626) 0.059 0.013 80 6.67 0.33 0.072 ( 0.623) 0.059 0.013 81 6.75 0.33 0.072 ( 0.620) 0.059 0.013 82 6.83 0.33 0.072 ( 0.617) 0.059 0.013 83 6.92 0.33 0.072 ( 0.614) 0.059 0.013 84 7.00 0.33 0.072 ( 0.612) 0.059 0.013 85 7.08 0.33 0.072 ( 0.609) 0.059 0.013 86 7.17 0.33 0.072 ( 0.606) 0.059 0.013 87 7.25 0.33 0.072 ( 0.603) 0.059 0.013 88 7.33 0.37 0.079 ( 0.600) 0.065 0.014 89 7.42 0.37 0.079 ( 0.598) 0.065 0.014 90 7.50 0.37 0.079 ( 0.595) 0.065 0.014 91 7.58 0.40 0.086 ( 0.592) 0.071 0.016 92 7.67 0.40 0.086 ( 0.589) 0.071 0.016 93 7.75 0.40 0.086 ( 0.587) 0.071 0.016 94 7.83 0.43 0.094 ( 0.584) 0.077 0.017 95 7.92 0.43 0.094 ( 0.581) 0.077 0.017 96 8.00 0.43 0.094 ( 0.579) 0.077 0.017 97 8.08 0.50 0.108 ( 0.576) 0.089 0.019 98 8.17 0.50 0.108 ( 0.573) 0.089 0.019 99 8.25 0.50 0.108 ( 0.571) 0.089 0.019 100 8.33 0.50 0.108 ( 0.568) 0.089 0.019 101 8.42 0.50 0.108 ( 0.565) 0.089 0.019 102 8.50 0.50 0.108 ( 0.563) 0.089 0.019 103 8.58 0.53 0.115 ( 0.560) 0.094 0.021 104 8.67 0.53 0.115 ( 0.557) 0.094 0.021 105 8.75 0.53 0.115 ( 0.555) 0.094 0.021 106 8.83 0.57 0.122 ( 0.552) 0.100 0.022 107 8.92 0.57 0.122 ( 0.550) 0.100 0.022 108 9.00 0.57 0.122 ( 0.547) 0.100 0.022 109 9.08 0.63 0.137 ( 0.544) 0.112 0.025 110 9.17 0.63 0.137 ( 0.542) 0.112 0.025 111 9.25 0.63 0.137 ( 0.539) 0.112 0.025 112 9.33 0.67 0.144 ( 0.537) 0.118 0.026 113 9.42 0.67 0.144 ( 0.534) 0.118 0.026 114 9.50 0.67 0.144 ( 0.531) 0.118 0.026 115 9.58 0.70 0.151 ( 0.529) 0.124 0.027 116 9.67 0.70 0.151 ( 0.526) 0.124 0.027 117 9.75 0.70 0.151 ( 0.524) 0.124 0.027 118 9.83 0.73 0.158 ( 0.521) 0.130 0.029 119 9.92 0.73 0.158 ( 0.519) 0.130 0.029 120 10.00 0.73 0.158 ( 0.516) 0.130 0.029 121 10.08 0.50 0.108 ( 0.514) 0.089 0.019 122 10.17 0.50 0.108 ( 0.511) 0.089 0.019 123 10.25 0.50 0.108 ( 0.509) 0.089 0.019 124 10.33 0.50 0.108 ( 0.506) 0.089 0.019 125 10.42 0.50 0.108 ( 0.504) 0.089 0.019 126 10.50 0.50 0.108 ( 0.501) 0.089 0.019 127 10.58 0.67 0.144 ( 0.499) 0.118 0.026 128 10.67 0.67 0.144 ( 0.497) 0.118 0.026 129 10.75 0.67 0.144 ( 0.494) 0.118 0.026 130 10.83 0.67 0.144 ( 0.492) 0.118 0.026 131 10.92 0.67 0.144 ( 0.489) 0.118 0.026 132 11.00 0.67 0.144 ( 0.487) 0.118 0.026 133 11.08 0.63 0.137 ( 0.485) 0.112 0.025 134 11.17 0.63 0.137 ( 0.482) 0.112 0.025 135 11.25 0.63 0.137 ( 0.480) 0.112 0.025 136 11.33 0.63 0.137 ( 0.477) 0.112 0.025 137 11.42 0.63 0.137 ( 0.475) 0.112 0.025 138 11.50 0.63 0.137 ( 0.473) 0.112 0.025 139 11.58 0.57 0.122 ( 0.470) 0.100 0.022 140 11.67 0.57 0.122 ( 0.468) 0.100 0.022 141 11.75 0.57 0.122 ( 0.466) 0.100 0.022 142 11.83 0.60 0.130 ( 0.463) 0.106 0.023 143 11.92 0.60 0.130 ( 0.461) 0.106 0.023 144 12.00 0.60 0.130 ( 0.459) 0.106 0.023 145 12.08 0.83 0.180 ( 0.456) 0.148 0.032 146 12.17 0.83 0.180 ( 0.454) 0.148 0.032 147 12.25 0.83 0.180 ( 0.452) 0.148 0.032 148 12.33 0.87 0.187 ( 0.450) 0.154 0.034 149 12.42 0.87 0.187 ( 0.447) 0.154 0.034 150 12.50 0.87 0.187 ( 0.445) 0.154 0.034 151 12.58 0.93 0.202 ( 0.443) 0.165 0.036 152 12.67 0.93 0.202 ( 0.441) 0.165 0.036 153 12.75 0.93 0.202 ( 0.438) 0.165 0.036 154 12.83 0.97 0.209 ( 0.436) 0.171 0.038 155 12.92 0.97 0.209 ( 0.434) 0.171 0.038 156 13.00 0.97 0.209 ( 0.432) 0.171 0.038 157 13.08 1.13 0.245 ( 0.430) 0.201 0.044 158 13.17 1.13 0.245 ( 0.427) 0.201 0.044 EX2YR24HR Page 4 of 9
159 13.25 1.13 0.245 ( 0.425) 0.201 0.044 160 13.33 1.13 0.245 ( 0.423) 0.201 0.044 161 13.42 1.13 0.245 ( 0.421) 0.201 0.044 162 13.50 1.13 0.245 ( 0.419) 0.201 0.044 163 13.58 0.77 0.166 ( 0.417) 0.136 0.030 164 13.67 0.77 0.166 ( 0.415) 0.136 0.030 165 13.75 0.77 0.166 ( 0.412) 0.136 0.030 166 13.83 0.77 0.166 ( 0.410) 0.136 0.030 167 13.92 0.77 0.166 ( 0.408) 0.136 0.030 168 14.00 0.77 0.166 ( 0.406) 0.136 0.030 169 14.08 0.90 0.194 ( 0.404) 0.159 0.035 170 14.17 0.90 0.194 ( 0.402) 0.159 0.035 171 14.25 0.90 0.194 ( 0.400) 0.159 0.035 172 14.33 0.87 0.187 ( 0.398) 0.154 0.034 173 14.42 0.87 0.187 ( 0.396) 0.154 0.034 174 14.50 0.87 0.187 ( 0.394) 0.154 0.034 175 14.58 0.87 0.187 ( 0.392) 0.154 0.034 176 14.67 0.87 0.187 ( 0.390) 0.154 0.034 177 14.75 0.87 0.187 ( 0.388) 0.154 0.034 178 14.83 0.83 0.180 ( 0.386) 0.148 0.032 179 14.92 0.83 0.180 ( 0.384) 0.148 0.032 180 15.00 0.83 0.180 ( 0.382) 0.148 0.032 181 15.08 0.80 0.173 ( 0.380) 0.142 0.031 182 15.17 0.80 0.173 ( 0.378) 0.142 0.031 183 15.25 0.80 0.173 ( 0.376) 0.142 0.031 184 15.33 0.77 0.166 ( 0.374) 0.136 0.030 185 15.42 0.77 0.166 ( 0.372) 0.136 0.030 186 15.50 0.77 0.166 ( 0.370) 0.136 0.030 187 15.58 0.63 0.137 ( 0.368) 0.112 0.025 188 15.67 0.63 0.137 ( 0.367) 0.112 0.025 189 15.75 0.63 0.137 ( 0.365) 0.112 0.025 190 15.83 0.63 0.137 ( 0.363) 0.112 0.025 191 15.92 0.63 0.137 ( 0.361) 0.112 0.025 192 16.00 0.63 0.137 ( 0.359) 0.112 0.025 193 16.08 0.13 0.029 ( 0.357) 0.024 0.005 194 16.17 0.13 0.029 ( 0.355) 0.024 0.005 195 16.25 0.13 0.029 ( 0.354) 0.024 0.005 196 16.33 0.13 0.029 ( 0.352) 0.024 0.005 197 16.42 0.13 0.029 ( 0.350) 0.024 0.005 198 16.50 0.13 0.029 ( 0.348) 0.024 0.005 199 16.58 0.10 0.022 ( 0.346) 0.018 0.004 200 16.67 0.10 0.022 ( 0.345) 0.018 0.004 201 16.75 0.10 0.022 ( 0.343) 0.018 0.004 202 16.83 0.10 0.022 ( 0.341) 0.018 0.004 203 16.92 0.10 0.022 ( 0.339) 0.018 0.004 204 17.00 0.10 0.022 ( 0.338) 0.018 0.004 205 17.08 0.17 0.036 ( 0.336) 0.030 0.006 206 17.17 0.17 0.036 ( 0.334) 0.030 0.006 207 17.25 0.17 0.036 ( 0.333) 0.030 0.006 208 17.33 0.17 0.036 ( 0.331) 0.030 0.006 209 17.42 0.17 0.036 ( 0.329) 0.030 0.006 210 17.50 0.17 0.036 ( 0.328) 0.030 0.006 211 17.58 0.17 0.036 ( 0.326) 0.030 0.006 212 17.67 0.17 0.036 ( 0.324) 0.030 0.006 213 17.75 0.17 0.036 ( 0.323) 0.030 0.006 214 17.83 0.13 0.029 ( 0.321) 0.024 0.005 215 17.92 0.13 0.029 ( 0.320) 0.024 0.005 216 18.00 0.13 0.029 ( 0.318) 0.024 0.005 217 18.08 0.13 0.029 ( 0.316) 0.024 0.005 218 18.17 0.13 0.029 ( 0.315) 0.024 0.005 219 18.25 0.13 0.029 ( 0.313) 0.024 0.005 220 18.33 0.13 0.029 ( 0.312) 0.024 0.005 221 18.42 0.13 0.029 ( 0.310) 0.024 0.005 222 18.50 0.13 0.029 ( 0.309) 0.024 0.005 223 18.58 0.10 0.022 ( 0.307) 0.018 0.004 224 18.67 0.10 0.022 ( 0.306) 0.018 0.004 225 18.75 0.10 0.022 ( 0.304) 0.018 0.004 226 18.83 0.07 0.014 ( 0.303) 0.012 0.003 227 18.92 0.07 0.014 ( 0.301) 0.012 0.003 228 19.00 0.07 0.014 ( 0.300) 0.012 0.003 229 19.08 0.10 0.022 ( 0.299) 0.018 0.004 230 19.17 0.10 0.022 ( 0.297) 0.018 0.004 231 19.25 0.10 0.022 ( 0.296) 0.018 0.004 232 19.33 0.13 0.029 ( 0.294) 0.024 0.005 233 19.42 0.13 0.029 ( 0.293) 0.024 0.005 234 19.50 0.13 0.029 ( 0.292) 0.024 0.005 235 19.58 0.10 0.022 ( 0.290) 0.018 0.004 236 19.67 0.10 0.022 ( 0.289) 0.018 0.004 237 19.75 0.10 0.022 ( 0.288) 0.018 0.004 238 19.83 0.07 0.014 ( 0.286) 0.012 0.003 239 19.92 0.07 0.014 ( 0.285) 0.012 0.003 240 20.00 0.07 0.014 ( 0.284) 0.012 0.003 241 20.08 0.10 0.022 ( 0.283) 0.018 0.004 242 20.17 0.10 0.022 ( 0.281) 0.018 0.004 243 20.25 0.10 0.022 ( 0.280) 0.018 0.004 244 20.33 0.10 0.022 ( 0.279) 0.018 0.004 EX2YR24HR Page 5 of 9
245 20.42 0.10 0.022 ( 0.278) 0.018 0.004 246 20.50 0.10 0.022 ( 0.277) 0.018 0.004 247 20.58 0.10 0.022 ( 0.275) 0.018 0.004 248 20.67 0.10 0.022 ( 0.274) 0.018 0.004 249 20.75 0.10 0.022 ( 0.273) 0.018 0.004 250 20.83 0.07 0.014 ( 0.272) 0.012 0.003 251 20.92 0.07 0.014 ( 0.271) 0.012 0.003 252 21.00 0.07 0.014 ( 0.270) 0.012 0.003 253 21.08 0.10 0.022 ( 0.269) 0.018 0.004 254 21.17 0.10 0.022 ( 0.268) 0.018 0.004 255 21.25 0.10 0.022 ( 0.267) 0.018 0.004 256 21.33 0.07 0.014 ( 0.266) 0.012 0.003 257 21.42 0.07 0.014 ( 0.265) 0.012 0.003 258 21.50 0.07 0.014 ( 0.264) 0.012 0.003 259 21.58 0.10 0.022 ( 0.263) 0.018 0.004 260 21.67 0.10 0.022 ( 0.262) 0.018 0.004 261 21.75 0.10 0.022 ( 0.261) 0.018 0.004 262 21.83 0.07 0.014 ( 0.260) 0.012 0.003 263 21.92 0.07 0.014 ( 0.259) 0.012 0.003 264 22.00 0.07 0.014 ( 0.258) 0.012 0.003 265 22.08 0.10 0.022 ( 0.257) 0.018 0.004 266 22.17 0.10 0.022 ( 0.256) 0.018 0.004 267 22.25 0.10 0.022 ( 0.256) 0.018 0.004 268 22.33 0.07 0.014 ( 0.255) 0.012 0.003 269 22.42 0.07 0.014 ( 0.254) 0.012 0.003 270 22.50 0.07 0.014 ( 0.253) 0.012 0.003 271 22.58 0.07 0.014 ( 0.253) 0.012 0.003 272 22.67 0.07 0.014 ( 0.252) 0.012 0.003 273 22.75 0.07 0.014 ( 0.251) 0.012 0.003 274 22.83 0.07 0.014 ( 0.251) 0.012 0.003 275 22.92 0.07 0.014 ( 0.250) 0.012 0.003 276 23.00 0.07 0.014 ( 0.249) 0.012 0.003 277 23.08 0.07 0.014 ( 0.249) 0.012 0.003 278 23.17 0.07 0.014 ( 0.248) 0.012 0.003 279 23.25 0.07 0.014 ( 0.248) 0.012 0.003 280 23.33 0.07 0.014 ( 0.247) 0.012 0.003 281 23.42 0.07 0.014 ( 0.247) 0.012 0.003 282 23.50 0.07 0.014 ( 0.246) 0.012 0.003 283 23.58 0.07 0.014 ( 0.246) 0.012 0.003 284 23.67 0.07 0.014 ( 0.245) 0.012 0.003 285 23.75 0.07 0.014 ( 0.245) 0.012 0.003 286 23.83 0.07 0.014 ( 0.245) 0.012 0.003 287 23.92 0.07 0.014 ( 0.245) 0.012 0.003 288 24.00 0.07 0.014 ( 0.245) 0.012 0.003 (Loss Rate Not Used)
Sum = 100.0 Sum = 3.9 Flood volume = Effective rainfall 0.32(In)
times area 7.0(Ac.)/[(In)/(Ft.)] = 0.2(Ac.Ft) Total soil loss = 1.48(In)
Total soil loss = 0.861(Ac.Ft)
Total rainfall = 1.80(In)
Flood volume = 8232.7 Cubic Feet
Total soil loss = 37504.6 Cubic Feet
-------------------------------------------------------------------- Peak flow rate of this hydrograph = 0.311(CFS)
-------------------------------------------------------------------- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 24 - H O U R S T O R M
R u n o f f H y d r o g r a p h
-------------------------------------------------------------------- Hydrograph in 5 Minute intervals ((CFS))
-------------------------------------------------------------------- Time(h+m) Volume Ac.Ft Q(CFS) 0 2.5 5.0 7.5 10.0 ----------------------------------------------------------------------- 0+ 5 0.0001 0.01 Q | | | | 0+10 0.0002 0.02 Q | | | | 0+15 0.0003 0.02 Q | | | | 0+20 0.0004 0.02 Q | | | | 0+25 0.0006 0.03 Q | | | | 0+30 0.0008 0.03 Q | | | | 0+35 0.0010 0.03 Q | | | | 0+40 0.0012 0.03 Q | | | | 0+45 0.0014 0.03 Q | | | | 0+50 0.0016 0.03 Q | | | | 0+55 0.0018 0.04 Q | | | | 1+ 0 0.0021 0.04 Q | | | | 1+ 5 0.0023 0.03 Q | | | | 1+10 0.0025 0.03 Q | | | | 1+15 0.0027 0.03 Q | | | | 1+20 0.0029 0.03 Q | | | | 1+25 0.0031 0.03 Q | | | | 1+30 0.0033 0.03 Q | | | | 1+35 0.0035 0.03 Q | | | | 1+40 0.0037 0.03 Q | | | | 1+45 0.0038 0.03 Q | | | | EX2YR24HR Page 6 of 9
1+50 0.0041 0.03 Q | | | | 1+55 0.0043 0.04 Q | | | | 2+ 0 0.0046 0.04 Q | | | | 2+ 5 0.0048 0.04 QV | | | | 2+10 0.0051 0.04 QV | | | | 2+15 0.0053 0.04 QV | | | | 2+20 0.0056 0.04 QV | | | | 2+25 0.0058 0.04 QV | | | | 2+30 0.0061 0.04 QV | | | | 2+35 0.0063 0.04 QV | | | | 2+40 0.0067 0.04 QV | | | | 2+45 0.0070 0.05 QV | | | | 2+50 0.0073 0.05 QV | | | | 2+55 0.0076 0.05 QV | | | | 3+ 0 0.0079 0.05 QV | | | | 3+ 5 0.0082 0.05 QV | | | | 3+10 0.0085 0.05 QV | | | | 3+15 0.0089 0.05 QV | | | | 3+20 0.0092 0.05 QV | | | | 3+25 0.0095 0.05 Q V | | | | 3+30 0.0098 0.05 Q V | | | | 3+35 0.0101 0.05 Q V | | | | 3+40 0.0104 0.05 Q V | | | | 3+45 0.0107 0.05 Q V | | | | 3+50 0.0111 0.05 Q V | | | | 3+55 0.0115 0.05 Q V | | | | 4+ 0 0.0118 0.05 Q V | | | | 4+ 5 0.0122 0.05 Q V | | | | 4+10 0.0126 0.05 Q V | | | | 4+15 0.0130 0.05 Q V | | | | 4+20 0.0134 0.06 Q V | | | | 4+25 0.0138 0.06 Q V | | | | 4+30 0.0143 0.06 Q V | | | | 4+35 0.0147 0.06 Q V | | | | 4+40 0.0151 0.06 Q V | | | | 4+45 0.0156 0.06 Q V | | | | 4+50 0.0160 0.07 Q V | | | | 4+55 0.0165 0.07 Q V | | | | 5+ 0 0.0170 0.07 Q V | | | | 5+ 5 0.0175 0.06 Q V | | | | 5+10 0.0179 0.06 Q V | | | | 5+15 0.0183 0.06 Q V | | | | 5+20 0.0187 0.06 Q V | | | | 5+25 0.0191 0.06 Q V | | | | 5+30 0.0195 0.06 Q V | | | | 5+35 0.0200 0.07 Q V | | | | 5+40 0.0205 0.07 Q V | | | | 5+45 0.0210 0.07 Q V | | | | 5+50 0.0215 0.07 Q V | | | | 5+55 0.0220 0.07 Q V | | | | 6+ 0 0.0225 0.07 Q V | | | | 6+ 5 0.0231 0.08 Q V | | | | 6+10 0.0236 0.08 Q V | | | | 6+15 0.0242 0.08 Q V | | | | 6+20 0.0248 0.08 Q V | | | | 6+25 0.0253 0.08 Q V | | | | 6+30 0.0259 0.08 Q V | | | | 6+35 0.0265 0.09 Q V | | | | 6+40 0.0271 0.09 Q V | | | | 6+45 0.0277 0.09 Q V | | | | 6+50 0.0284 0.09 Q V | | | | 6+55 0.0290 0.09 Q V | | | | 7+ 0 0.0296 0.09 Q V | | | | 7+ 5 0.0303 0.09 Q V | | | | 7+10 0.0309 0.09 Q V | | | | 7+15 0.0315 0.09 Q V | | | | 7+20 0.0322 0.10 Q V | | | | 7+25 0.0329 0.10 Q V | | | | 7+30 0.0336 0.10 Q V | | | | 7+35 0.0343 0.10 Q V | | | | 7+40 0.0350 0.11 Q V | | | | 7+45 0.0358 0.11 Q V | | | | 7+50 0.0366 0.11 Q V | | | | 7+55 0.0374 0.12 Q V | | | | 8+ 0 0.0382 0.12 Q V | | | | 8+ 5 0.0391 0.13 Q V | | | | 8+10 0.0400 0.14 Q V | | | | 8+15 0.0409 0.14 Q V | | | | 8+20 0.0419 0.14 Q V | | | | 8+25 0.0428 0.14 Q V| | | | 8+30 0.0438 0.14 Q V| | | | 8+35 0.0448 0.14 Q V| | | | 8+40 0.0458 0.15 Q V| | | | 8+45 0.0468 0.15 Q V| | | | 8+50 0.0478 0.15 Q V | | | 8+55 0.0489 0.15 Q V | | | EX2YR24HR Page 7 of 9
9+ 0 0.0499 0.16 Q V | | | 9+ 5 0.0511 0.16 Q V | | | 9+10 0.0522 0.17 Q |V | | | 9+15 0.0534 0.17 Q |V | | | 9+20 0.0547 0.18 Q |V | | | 9+25 0.0559 0.18 Q |V | | | 9+30 0.0572 0.18 Q | V | | | 9+35 0.0585 0.19 Q | V | | | 9+40 0.0598 0.19 Q | V | | | 9+45 0.0611 0.19 Q | V | | | 9+50 0.0625 0.20 Q | V | | | 9+55 0.0638 0.20 Q | V | | | 10+ 0 0.0652 0.20 Q | V | | | 10+ 5 0.0664 0.17 Q | V | | | 10+10 0.0674 0.14 Q | V | | | 10+15 0.0683 0.14 Q | V | | | 10+20 0.0693 0.14 Q | V | | | 10+25 0.0702 0.14 Q | V | | | 10+30 0.0712 0.14 Q | V | | | 10+35 0.0723 0.16 Q | V | | | 10+40 0.0735 0.18 Q | V | | | 10+45 0.0747 0.18 Q | V | | | 10+50 0.0760 0.18 Q | V | | | 10+55 0.0773 0.18 Q | V | | | 11+ 0 0.0785 0.18 Q | V | | | 11+ 5 0.0798 0.18 Q | V | | | 11+10 0.0810 0.17 Q | V | | | 11+15 0.0822 0.17 Q | V | | | 11+20 0.0834 0.17 Q | V | | | 11+25 0.0846 0.17 Q | V | | | 11+30 0.0858 0.17 Q | V | | | 11+35 0.0869 0.17 Q | V | | | 11+40 0.0880 0.16 Q | V | | | 11+45 0.0891 0.16 Q | V | | | 11+50 0.0902 0.16 Q | V| | | 11+55 0.0913 0.16 Q | V| | | 12+ 0 0.0924 0.16 Q | V| | | 12+ 5 0.0938 0.19 Q | V| | | 12+10 0.0953 0.22 Q | V | | 12+15 0.0968 0.23 Q | V | | 12+20 0.0984 0.23 Q | V | | 12+25 0.1001 0.24 Q | |V | | 12+30 0.1017 0.24 Q | |V | | 12+35 0.1034 0.25 Q | |V | | 12+40 0.1052 0.25 |Q | | V | | 12+45 0.1069 0.26 |Q | | V | | 12+50 0.1087 0.26 |Q | | V | | 12+55 0.1105 0.26 |Q | | V | | 13+ 0 0.1124 0.26 |Q | | V | | 13+ 5 0.1143 0.29 |Q | | V | | 13+10 0.1164 0.31 |Q | | V | | 13+15 0.1186 0.31 |Q | | V | | 13+20 0.1207 0.31 |Q | | V | | 13+25 0.1229 0.31 |Q | | V | | 13+30 0.1250 0.31 |Q | | V | | 13+35 0.1268 0.26 |Q | | V | | 13+40 0.1283 0.22 Q | | V | | 13+45 0.1298 0.21 Q | | V | | 13+50 0.1313 0.21 Q | | V | | 13+55 0.1327 0.21 Q | | V | | 14+ 0 0.1342 0.21 Q | | V | | 14+ 5 0.1357 0.23 Q | | V | | 14+10 0.1374 0.24 Q | | V| | 14+15 0.1391 0.25 Q | | V| | 14+20 0.1408 0.24 Q | | V| | 14+25 0.1424 0.24 Q | | V | 14+30 0.1440 0.24 Q | | V | 14+35 0.1457 0.24 Q | | V | 14+40 0.1473 0.24 Q | | |V | 14+45 0.1490 0.24 Q | | |V | 14+50 0.1506 0.23 Q | | |V | 14+55 0.1521 0.23 Q | | | V | 15+ 0 0.1537 0.23 Q | | | V | 15+ 5 0.1553 0.22 Q | | | V | 15+10 0.1568 0.22 Q | | | V | 15+15 0.1583 0.22 Q | | | V | 15+20 0.1598 0.22 Q | | | V | 15+25 0.1612 0.21 Q | | | V | 15+30 0.1627 0.21 Q | | | V | 15+35 0.1640 0.19 Q | | | V | 15+40 0.1652 0.18 Q | | | V | 15+45 0.1665 0.17 Q | | | V | 15+50 0.1677 0.17 Q | | | V | 15+55 0.1688 0.17 Q | | | V | 16+ 0 0.1700 0.17 Q | | | V | 16+ 5 0.1708 0.11 Q | | | V | EX2YR24HR Page 8 of 9
16+10 0.1712 0.05 Q | | | V | 16+15 0.1714 0.04 Q | | | V | 16+20 0.1717 0.04 Q | | | V | 16+25 0.1719 0.04 Q | | | V | 16+30 0.1722 0.04 Q | | | V | 16+35 0.1724 0.03 Q | | | V | 16+40 0.1726 0.03 Q | | | V | 16+45 0.1728 0.03 Q | | | V | 16+50 0.1730 0.03 Q | | | V | 16+55 0.1732 0.03 Q | | | V | 17+ 0 0.1734 0.03 Q | | | V | 17+ 5 0.1736 0.04 Q | | | V | 17+10 0.1739 0.04 Q | | | V | 17+15 0.1742 0.05 Q | | | V | 17+20 0.1745 0.05 Q | | | V | 17+25 0.1749 0.05 Q | | | V | 17+30 0.1752 0.05 Q | | | V | 17+35 0.1755 0.05 Q | | | V | 17+40 0.1758 0.05 Q | | | V | 17+45 0.1761 0.05 Q | | | V | 17+50 0.1764 0.04 Q | | | V | 17+55 0.1767 0.04 Q | | | V | 18+ 0 0.1769 0.04 Q | | | V | 18+ 5 0.1772 0.04 Q | | | V | 18+10 0.1774 0.04 Q | | | V | 18+15 0.1777 0.04 Q | | | V | 18+20 0.1779 0.04 Q | | | V | 18+25 0.1782 0.04 Q | | | V | 18+30 0.1784 0.04 Q | | | V | 18+35 0.1787 0.03 Q | | | V | 18+40 0.1789 0.03 Q | | | V | 18+45 0.1790 0.03 Q | | | V | 18+50 0.1792 0.02 Q | | | V | 18+55 0.1793 0.02 Q | | | V | 19+ 0 0.1795 0.02 Q | | | V | 19+ 5 0.1796 0.02 Q | | | V | 19+10 0.1798 0.03 Q | | | V | 19+15 0.1800 0.03 Q | | | V | 19+20 0.1802 0.03 Q | | | V | 19+25 0.1805 0.04 Q | | | V | 19+30 0.1807 0.04 Q | | | V | 19+35 0.1809 0.03 Q | | | V | 19+40 0.1811 0.03 Q | | | V | 19+45 0.1813 0.03 Q | | | V | 19+50 0.1815 0.02 Q | | | V | 19+55 0.1816 0.02 Q | | | V | 20+ 0 0.1817 0.02 Q | | | V | 20+ 5 0.1819 0.02 Q | | | V | 20+10 0.1821 0.03 Q | | | V | 20+15 0.1823 0.03 Q | | | V | 20+20 0.1824 0.03 Q | | | V | 20+25 0.1826 0.03 Q | | | V | 20+30 0.1828 0.03 Q | | | V | 20+35 0.1830 0.03 Q | | | V | 20+40 0.1832 0.03 Q | | | V | 20+45 0.1834 0.03 Q | | | V | 20+50 0.1835 0.02 Q | | | V | 20+55 0.1837 0.02 Q | | | V | 21+ 0 0.1838 0.02 Q | | | V | 21+ 5 0.1840 0.02 Q | | | V | 21+10 0.1841 0.03 Q | | | V | 21+15 0.1843 0.03 Q | | | V| 21+20 0.1845 0.02 Q | | | V| 21+25 0.1846 0.02 Q | | | V| 21+30 0.1848 0.02 Q | | | V| 21+35 0.1849 0.02 Q | | | V| 21+40 0.1851 0.03 Q | | | V| 21+45 0.1853 0.03 Q | | | V| 21+50 0.1854 0.02 Q | | | V| 21+55 0.1856 0.02 Q | | | V| 22+ 0 0.1857 0.02 Q | | | V| 22+ 5 0.1859 0.02 Q | | | V| 22+10 0.1860 0.03 Q | | | V| 22+15 0.1862 0.03 Q | | | V| 22+20 0.1864 0.02 Q | | | V| 22+25 0.1865 0.02 Q | | | V| 22+30 0.1866 0.02 Q | | | V| 22+35 0.1868 0.02 Q | | | V| 22+40 0.1869 0.02 Q | | | V| 22+45 0.1870 0.02 Q | | | V| 22+50 0.1871 0.02 Q | | | V| 22+55 0.1873 0.02 Q | | | V| 23+ 0 0.1874 0.02 Q | | | V| 23+ 5 0.1875 0.02 Q | | | V| 23+10 0.1877 0.02 Q | | | V| 23+15 0.1878 0.02 Q | | | V| EX2YR24HR Page 9 of 9
23+20 0.1879 0.02 Q | | | V| 23+25 0.1880 0.02 Q | | | V| 23+30 0.1882 0.02 Q | | | V| 23+35 0.1883 0.02 Q | | | V| 23+40 0.1884 0.02 Q | | | V| 23+45 0.1885 0.02 Q | | | V| 23+50 0.1887 0.02 Q | | | V| 23+55 0.1888 0.02 Q | | | V| 24+ 0 0.1889 0.02 Q | | | V| 24+ 5 0.1890 0.01 Q | | | V| 24+10 0.1890 0.00 Q | | | V| 24+15 0.1890 0.00 Q | | | V| ----------------------------------------------------------------------- PRO 2YR24HR Page 1 of 9
U n i t H y d r o g r a p h A n a l y s i s
Copyright (c) CIVILCADD/CIVILDESIGN, 1989 - 2008, Version 8.1 Study date 02/22/24 File: 2YR242.out
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ------------------------------------------------------------------------ Riverside County Synthetic Unit Hydrology Method
RCFC & WCD Manual date - April 1978
Program License Serial Number 5006
--------------------------------------------------------------------- English (in-lb) Input Units Used
English Rainfall Data (Inches) Input Values Used
English Units used in output format
--------------------------------------------------------------------- -------------------------------------------------------------------- Drainage Area = 7.00(Ac.) = 0.011 Sq. Mi.

Drainage Area for Depth-Area Areal Adjustment = 7.00(Ac.) = 0.011 Sq. Mi.

Length along longest watercourse = 861.00(Ft.)
Length along longest watercourse measured to centroid = 430.00(Ft.) Length along longest watercourse = 0.163 Mi.

Length along longest watercourse measured to centroid = 0.081 Mi.

Difference in elevation = 16.90(Ft.)
Slope along watercourse = 103.6376 Ft./Mi.

Average Manning's 'N' = 0.015
Lag time = 0.029 Hr.

Lag time = 1.73 Min.
25% of lag time = 0.43 Min.
40% of lag time = 0.69 Min.

Unit time = 5.00 Min.

Duration of storm = 24 Hour(s)
User Entered Base Flow = 0.00(CFS)
2 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

7.00 1.80 12.60
100 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

7.00 6.00 42.00
STORM EVENT (YEAR) = 2.00
Area Averaged 2-Year Rainfall = 1.800(In)
Area Averaged 100-Year Rainfall = 6.000(In)
Point rain (area averaged) = 1.800(In)
Areal adjustment factor = 100.00 %
Adjusted average point rain = 1.800(In)
Sub-Area Data:

Area(Ac.) Runoff Index Impervious %

7.000 69.00 0.600
Total Area Entered = 7.00(Ac.)
RI RI Infil. Rate Impervious Adj. Infil. Rate Area% F AMC2 AMC-1 (In/Hr) (Dec.%) (In/Hr) (Dec.) (In/Hr)

69.0 49.8 0.574 0.600 0.264 1.000 0.264 Sum (F) = 0.264
Area averaged mean soil loss (F) (In/Hr) = 0.264
Minimum soil loss rate ((In/Hr)) = 0.132
(for 24 hour storm duration)
Soil low loss rate (decimal) = 0.420
--------------------------------------------------------------------- U n i t H y d r o g r a p h
VALLEY S-Curve
-------------------------------------------------------------------- Unit Hydrograph Data
--------------------------------------------------------------------- Unit time period Time % of lag Distribution Unit Hydrograph (hrs) Graph % (CFS) PRO 2YR24HR Page 2 of 9
--------------------------------------------------------------------- 1 0.083 288.833 55.504 3.916 2 0.167 577.666 37.752 2.663 3 0.250 866.500 6.744 0.476 Sum = 100.000 Sum= 7.055
----------------------------------------------------------------------- The following loss rate calculations reflect use of the minimum calculated loss rate subtracted from the Storm Rain to produce the maximum Effective Rain value Unit Time Pattern Storm Rain Loss rate(In./Hr) Effective (Hr.) Percent (In/Hr) Max | Low (In/Hr) 1 0.08 0.07 0.014 ( 0.468) 0.006 0.008 2 0.17 0.07 0.014 ( 0.466) 0.006 0.008 3 0.25 0.07 0.014 ( 0.464) 0.006 0.008 4 0.33 0.10 0.022 ( 0.463) 0.009 0.013 5 0.42 0.10 0.022 ( 0.461) 0.009 0.013 6 0.50 0.10 0.022 ( 0.459) 0.009 0.013 7 0.58 0.10 0.022 ( 0.457) 0.009 0.013 8 0.67 0.10 0.022 ( 0.455) 0.009 0.013 9 0.75 0.10 0.022 ( 0.454) 0.009 0.013 10 0.83 0.13 0.029 ( 0.452) 0.012 0.017 11 0.92 0.13 0.029 ( 0.450) 0.012 0.017 12 1.00 0.13 0.029 ( 0.448) 0.012 0.017 13 1.08 0.10 0.022 ( 0.447) 0.009 0.013 14 1.17 0.10 0.022 ( 0.445) 0.009 0.013 15 1.25 0.10 0.022 ( 0.443) 0.009 0.013 16 1.33 0.10 0.022 ( 0.441) 0.009 0.013 17 1.42 0.10 0.022 ( 0.439) 0.009 0.013 18 1.50 0.10 0.022 ( 0.438) 0.009 0.013 19 1.58 0.10 0.022 ( 0.436) 0.009 0.013 20 1.67 0.10 0.022 ( 0.434) 0.009 0.013 21 1.75 0.10 0.022 ( 0.433) 0.009 0.013 22 1.83 0.13 0.029 ( 0.431) 0.012 0.017 23 1.92 0.13 0.029 ( 0.429) 0.012 0.017 24 2.00 0.13 0.029 ( 0.427) 0.012 0.017 25 2.08 0.13 0.029 ( 0.426) 0.012 0.017 26 2.17 0.13 0.029 ( 0.424) 0.012 0.017 27 2.25 0.13 0.029 ( 0.422) 0.012 0.017 28 2.33 0.13 0.029 ( 0.420) 0.012 0.017 29 2.42 0.13 0.029 ( 0.419) 0.012 0.017 30 2.50 0.13 0.029 ( 0.417) 0.012 0.017 31 2.58 0.17 0.036 ( 0.415) 0.015 0.021 32 2.67 0.17 0.036 ( 0.414) 0.015 0.021 33 2.75 0.17 0.036 ( 0.412) 0.015 0.021 34 2.83 0.17 0.036 ( 0.410) 0.015 0.021 35 2.92 0.17 0.036 ( 0.408) 0.015 0.021 36 3.00 0.17 0.036 ( 0.407) 0.015 0.021 37 3.08 0.17 0.036 ( 0.405) 0.015 0.021 38 3.17 0.17 0.036 ( 0.403) 0.015 0.021 39 3.25 0.17 0.036 ( 0.402) 0.015 0.021 40 3.33 0.17 0.036 ( 0.400) 0.015 0.021 41 3.42 0.17 0.036 ( 0.398) 0.015 0.021 42 3.50 0.17 0.036 ( 0.397) 0.015 0.021 43 3.58 0.17 0.036 ( 0.395) 0.015 0.021 44 3.67 0.17 0.036 ( 0.393) 0.015 0.021 45 3.75 0.17 0.036 ( 0.392) 0.015 0.021 46 3.83 0.20 0.043 ( 0.390) 0.018 0.025 47 3.92 0.20 0.043 ( 0.388) 0.018 0.025 48 4.00 0.20 0.043 ( 0.387) 0.018 0.025 49 4.08 0.20 0.043 ( 0.385) 0.018 0.025 50 4.17 0.20 0.043 ( 0.384) 0.018 0.025 51 4.25 0.20 0.043 ( 0.382) 0.018 0.025 52 4.33 0.23 0.050 ( 0.380) 0.021 0.029 53 4.42 0.23 0.050 ( 0.379) 0.021 0.029 54 4.50 0.23 0.050 ( 0.377) 0.021 0.029 55 4.58 0.23 0.050 ( 0.375) 0.021 0.029 56 4.67 0.23 0.050 ( 0.374) 0.021 0.029 57 4.75 0.23 0.050 ( 0.372) 0.021 0.029 58 4.83 0.27 0.058 ( 0.371) 0.024 0.033 59 4.92 0.27 0.058 ( 0.369) 0.024 0.033 60 5.00 0.27 0.058 ( 0.367) 0.024 0.033 61 5.08 0.20 0.043 ( 0.366) 0.018 0.025 62 5.17 0.20 0.043 ( 0.364) 0.018 0.025 63 5.25 0.20 0.043 ( 0.363) 0.018 0.025 64 5.33 0.23 0.050 ( 0.361) 0.021 0.029 65 5.42 0.23 0.050 ( 0.359) 0.021 0.029 66 5.50 0.23 0.050 ( 0.358) 0.021 0.029 67 5.58 0.27 0.058 ( 0.356) 0.024 0.033 68 5.67 0.27 0.058 ( 0.355) 0.024 0.033 69 5.75 0.27 0.058 ( 0.353) 0.024 0.033 70 5.83 0.27 0.058 ( 0.352) 0.024 0.033 71 5.92 0.27 0.058 ( 0.350) 0.024 0.033 72 6.00 0.27 0.058 ( 0.349) 0.024 0.033 73 6.08 0.30 0.065 ( 0.347) 0.027 0.038 PRO 2YR24HR Page 3 of 9
74 6.17 0.30 0.065 ( 0.345) 0.027 0.038 75 6.25 0.30 0.065 ( 0.344) 0.027 0.038 76 6.33 0.30 0.065 ( 0.342) 0.027 0.038 77 6.42 0.30 0.065 ( 0.341) 0.027 0.038 78 6.50 0.30 0.065 ( 0.339) 0.027 0.038 79 6.58 0.33 0.072 ( 0.338) 0.030 0.042 80 6.67 0.33 0.072 ( 0.336) 0.030 0.042 81 6.75 0.33 0.072 ( 0.335) 0.030 0.042 82 6.83 0.33 0.072 ( 0.333) 0.030 0.042 83 6.92 0.33 0.072 ( 0.332) 0.030 0.042 84 7.00 0.33 0.072 ( 0.330) 0.030 0.042 85 7.08 0.33 0.072 ( 0.329) 0.030 0.042 86 7.17 0.33 0.072 ( 0.327) 0.030 0.042 87 7.25 0.33 0.072 ( 0.326) 0.030 0.042 88 7.33 0.37 0.079 ( 0.324) 0.033 0.046 89 7.42 0.37 0.079 ( 0.323) 0.033 0.046 90 7.50 0.37 0.079 ( 0.321) 0.033 0.046 91 7.58 0.40 0.086 ( 0.320) 0.036 0.050 92 7.67 0.40 0.086 ( 0.318) 0.036 0.050 93 7.75 0.40 0.086 ( 0.317) 0.036 0.050 94 7.83 0.43 0.094 ( 0.315) 0.039 0.054 95 7.92 0.43 0.094 ( 0.314) 0.039 0.054 96 8.00 0.43 0.094 ( 0.312) 0.039 0.054 97 8.08 0.50 0.108 ( 0.311) 0.045 0.063 98 8.17 0.50 0.108 ( 0.310) 0.045 0.063 99 8.25 0.50 0.108 ( 0.308) 0.045 0.063 100 8.33 0.50 0.108 ( 0.307) 0.045 0.063 101 8.42 0.50 0.108 ( 0.305) 0.045 0.063 102 8.50 0.50 0.108 ( 0.304) 0.045 0.063 103 8.58 0.53 0.115 ( 0.302) 0.048 0.067 104 8.67 0.53 0.115 ( 0.301) 0.048 0.067 105 8.75 0.53 0.115 ( 0.300) 0.048 0.067 106 8.83 0.57 0.122 ( 0.298) 0.051 0.071 107 8.92 0.57 0.122 ( 0.297) 0.051 0.071 108 9.00 0.57 0.122 ( 0.295) 0.051 0.071 109 9.08 0.63 0.137 ( 0.294) 0.057 0.079 110 9.17 0.63 0.137 ( 0.293) 0.057 0.079 111 9.25 0.63 0.137 ( 0.291) 0.057 0.079 112 9.33 0.67 0.144 ( 0.290) 0.060 0.084 113 9.42 0.67 0.144 ( 0.288) 0.060 0.084 114 9.50 0.67 0.144 ( 0.287) 0.060 0.084 115 9.58 0.70 0.151 ( 0.286) 0.064 0.088 116 9.67 0.70 0.151 ( 0.284) 0.064 0.088 117 9.75 0.70 0.151 ( 0.283) 0.064 0.088 118 9.83 0.73 0.158 ( 0.282) 0.067 0.092 119 9.92 0.73 0.158 ( 0.280) 0.067 0.092 120 10.00 0.73 0.158 ( 0.279) 0.067 0.092 121 10.08 0.50 0.108 ( 0.277) 0.045 0.063 122 10.17 0.50 0.108 ( 0.276) 0.045 0.063 123 10.25 0.50 0.108 ( 0.275) 0.045 0.063 124 10.33 0.50 0.108 ( 0.273) 0.045 0.063 125 10.42 0.50 0.108 ( 0.272) 0.045 0.063 126 10.50 0.50 0.108 ( 0.271) 0.045 0.063 127 10.58 0.67 0.144 ( 0.269) 0.060 0.084 128 10.67 0.67 0.144 ( 0.268) 0.060 0.084 129 10.75 0.67 0.144 ( 0.267) 0.060 0.084 130 10.83 0.67 0.144 ( 0.266) 0.060 0.084 131 10.92 0.67 0.144 ( 0.264) 0.060 0.084 132 11.00 0.67 0.144 ( 0.263) 0.060 0.084 133 11.08 0.63 0.137 ( 0.262) 0.057 0.079 134 11.17 0.63 0.137 ( 0.260) 0.057 0.079 135 11.25 0.63 0.137 ( 0.259) 0.057 0.079 136 11.33 0.63 0.137 ( 0.258) 0.057 0.079 137 11.42 0.63 0.137 ( 0.256) 0.057 0.079 138 11.50 0.63 0.137 ( 0.255) 0.057 0.079 139 11.58 0.57 0.122 ( 0.254) 0.051 0.071 140 11.67 0.57 0.122 ( 0.253) 0.051 0.071 141 11.75 0.57 0.122 ( 0.251) 0.051 0.071 142 11.83 0.60 0.130 ( 0.250) 0.054 0.075 143 11.92 0.60 0.130 ( 0.249) 0.054 0.075 144 12.00 0.60 0.130 ( 0.248) 0.054 0.075 145 12.08 0.83 0.180 ( 0.246) 0.076 0.104 146 12.17 0.83 0.180 ( 0.245) 0.076 0.104 147 12.25 0.83 0.180 ( 0.244) 0.076 0.104 148 12.33 0.87 0.187 ( 0.243) 0.079 0.109 149 12.42 0.87 0.187 ( 0.242) 0.079 0.109 150 12.50 0.87 0.187 ( 0.240) 0.079 0.109 151 12.58 0.93 0.202 ( 0.239) 0.085 0.117 152 12.67 0.93 0.202 ( 0.238) 0.085 0.117 153 12.75 0.93 0.202 ( 0.237) 0.085 0.117 154 12.83 0.97 0.209 ( 0.236) 0.088 0.121 155 12.92 0.97 0.209 ( 0.234) 0.088 0.121 156 13.00 0.97 0.209 ( 0.233) 0.088 0.121 157 13.08 1.13 0.245 ( 0.232) 0.103 0.142 158 13.17 1.13 0.245 ( 0.231) 0.103 0.142 159 13.25 1.13 0.245 ( 0.230) 0.103 0.142 PRO 2YR24HR Page 4 of 9
160 13.33 1.13 0.245 ( 0.228) 0.103 0.142 161 13.42 1.13 0.245 ( 0.227) 0.103 0.142 162 13.50 1.13 0.245 ( 0.226) 0.103 0.142 163 13.58 0.77 0.166 ( 0.225) 0.070 0.096 164 13.67 0.77 0.166 ( 0.224) 0.070 0.096 165 13.75 0.77 0.166 ( 0.223) 0.070 0.096 166 13.83 0.77 0.166 ( 0.222) 0.070 0.096 167 13.92 0.77 0.166 ( 0.220) 0.070 0.096 168 14.00 0.77 0.166 ( 0.219) 0.070 0.096 169 14.08 0.90 0.194 ( 0.218) 0.082 0.113 170 14.17 0.90 0.194 ( 0.217) 0.082 0.113 171 14.25 0.90 0.194 ( 0.216) 0.082 0.113 172 14.33 0.87 0.187 ( 0.215) 0.079 0.109 173 14.42 0.87 0.187 ( 0.214) 0.079 0.109 174 14.50 0.87 0.187 ( 0.213) 0.079 0.109 175 14.58 0.87 0.187 ( 0.212) 0.079 0.109 176 14.67 0.87 0.187 ( 0.210) 0.079 0.109 177 14.75 0.87 0.187 ( 0.209) 0.079 0.109 178 14.83 0.83 0.180 ( 0.208) 0.076 0.104 179 14.92 0.83 0.180 ( 0.207) 0.076 0.104 180 15.00 0.83 0.180 ( 0.206) 0.076 0.104 181 15.08 0.80 0.173 ( 0.205) 0.073 0.100 182 15.17 0.80 0.173 ( 0.204) 0.073 0.100 183 15.25 0.80 0.173 ( 0.203) 0.073 0.100 184 15.33 0.77 0.166 ( 0.202) 0.070 0.096 185 15.42 0.77 0.166 ( 0.201) 0.070 0.096 186 15.50 0.77 0.166 ( 0.200) 0.070 0.096 187 15.58 0.63 0.137 ( 0.199) 0.057 0.079 188 15.67 0.63 0.137 ( 0.198) 0.057 0.079 189 15.75 0.63 0.137 ( 0.197) 0.057 0.079 190 15.83 0.63 0.137 ( 0.196) 0.057 0.079 191 15.92 0.63 0.137 ( 0.195) 0.057 0.079 192 16.00 0.63 0.137 ( 0.194) 0.057 0.079 193 16.08 0.13 0.029 ( 0.193) 0.012 0.017 194 16.17 0.13 0.029 ( 0.192) 0.012 0.017 195 16.25 0.13 0.029 ( 0.191) 0.012 0.017 196 16.33 0.13 0.029 ( 0.190) 0.012 0.017 197 16.42 0.13 0.029 ( 0.189) 0.012 0.017 198 16.50 0.13 0.029 ( 0.188) 0.012 0.017 199 16.58 0.10 0.022 ( 0.187) 0.009 0.013 200 16.67 0.10 0.022 ( 0.186) 0.009 0.013 201 16.75 0.10 0.022 ( 0.185) 0.009 0.013 202 16.83 0.10 0.022 ( 0.184) 0.009 0.013 203 16.92 0.10 0.022 ( 0.183) 0.009 0.013 204 17.00 0.10 0.022 ( 0.182) 0.009 0.013 205 17.08 0.17 0.036 ( 0.181) 0.015 0.021 206 17.17 0.17 0.036 ( 0.181) 0.015 0.021 207 17.25 0.17 0.036 ( 0.180) 0.015 0.021 208 17.33 0.17 0.036 ( 0.179) 0.015 0.021 209 17.42 0.17 0.036 ( 0.178) 0.015 0.021 210 17.50 0.17 0.036 ( 0.177) 0.015 0.021 211 17.58 0.17 0.036 ( 0.176) 0.015 0.021 212 17.67 0.17 0.036 ( 0.175) 0.015 0.021 213 17.75 0.17 0.036 ( 0.174) 0.015 0.021 214 17.83 0.13 0.029 ( 0.173) 0.012 0.017 215 17.92 0.13 0.029 ( 0.173) 0.012 0.017 216 18.00 0.13 0.029 ( 0.172) 0.012 0.017 217 18.08 0.13 0.029 ( 0.171) 0.012 0.017 218 18.17 0.13 0.029 ( 0.170) 0.012 0.017 219 18.25 0.13 0.029 ( 0.169) 0.012 0.017 220 18.33 0.13 0.029 ( 0.168) 0.012 0.017 221 18.42 0.13 0.029 ( 0.168) 0.012 0.017 222 18.50 0.13 0.029 ( 0.167) 0.012 0.017 223 18.58 0.10 0.022 ( 0.166) 0.009 0.013 224 18.67 0.10 0.022 ( 0.165) 0.009 0.013 225 18.75 0.10 0.022 ( 0.164) 0.009 0.013 226 18.83 0.07 0.014 ( 0.164) 0.006 0.008 227 18.92 0.07 0.014 ( 0.163) 0.006 0.008 228 19.00 0.07 0.014 ( 0.162) 0.006 0.008 229 19.08 0.10 0.022 ( 0.161) 0.009 0.013 230 19.17 0.10 0.022 ( 0.160) 0.009 0.013 231 19.25 0.10 0.022 ( 0.160) 0.009 0.013 232 19.33 0.13 0.029 ( 0.159) 0.012 0.017 233 19.42 0.13 0.029 ( 0.158) 0.012 0.017 234 19.50 0.13 0.029 ( 0.158) 0.012 0.017 235 19.58 0.10 0.022 ( 0.157) 0.009 0.013 236 19.67 0.10 0.022 ( 0.156) 0.009 0.013 237 19.75 0.10 0.022 ( 0.155) 0.009 0.013 238 19.83 0.07 0.014 ( 0.155) 0.006 0.008 239 19.92 0.07 0.014 ( 0.154) 0.006 0.008 240 20.00 0.07 0.014 ( 0.153) 0.006 0.008 241 20.08 0.10 0.022 ( 0.153) 0.009 0.013 242 20.17 0.10 0.022 ( 0.152) 0.009 0.013 243 20.25 0.10 0.022 ( 0.151) 0.009 0.013 244 20.33 0.10 0.022 ( 0.151) 0.009 0.013 245 20.42 0.10 0.022 ( 0.150) 0.009 0.013 PRO 2YR24HR Page 5 of 9
246 20.50 0.10 0.022 ( 0.149) 0.009 0.013 247 20.58 0.10 0.022 ( 0.149) 0.009 0.013 248 20.67 0.10 0.022 ( 0.148) 0.009 0.013 249 20.75 0.10 0.022 ( 0.148) 0.009 0.013 250 20.83 0.07 0.014 ( 0.147) 0.006 0.008 251 20.92 0.07 0.014 ( 0.146) 0.006 0.008 252 21.00 0.07 0.014 ( 0.146) 0.006 0.008 253 21.08 0.10 0.022 ( 0.145) 0.009 0.013 254 21.17 0.10 0.022 ( 0.145) 0.009 0.013 255 21.25 0.10 0.022 ( 0.144) 0.009 0.013 256 21.33 0.07 0.014 ( 0.143) 0.006 0.008 257 21.42 0.07 0.014 ( 0.143) 0.006 0.008 258 21.50 0.07 0.014 ( 0.142) 0.006 0.008 259 21.58 0.10 0.022 ( 0.142) 0.009 0.013 260 21.67 0.10 0.022 ( 0.141) 0.009 0.013 261 21.75 0.10 0.022 ( 0.141) 0.009 0.013 262 21.83 0.07 0.014 ( 0.140) 0.006 0.008 263 21.92 0.07 0.014 ( 0.140) 0.006 0.008 264 22.00 0.07 0.014 ( 0.139) 0.006 0.008 265 22.08 0.10 0.022 ( 0.139) 0.009 0.013 266 22.17 0.10 0.022 ( 0.138) 0.009 0.013 267 22.25 0.10 0.022 ( 0.138) 0.009 0.013 268 22.33 0.07 0.014 ( 0.138) 0.006 0.008 269 22.42 0.07 0.014 ( 0.137) 0.006 0.008 270 22.50 0.07 0.014 ( 0.137) 0.006 0.008 271 22.58 0.07 0.014 ( 0.136) 0.006 0.008 272 22.67 0.07 0.014 ( 0.136) 0.006 0.008 273 22.75 0.07 0.014 ( 0.136) 0.006 0.008 274 22.83 0.07 0.014 ( 0.135) 0.006 0.008 275 22.92 0.07 0.014 ( 0.135) 0.006 0.008 276 23.00 0.07 0.014 ( 0.135) 0.006 0.008 277 23.08 0.07 0.014 ( 0.134) 0.006 0.008 278 23.17 0.07 0.014 ( 0.134) 0.006 0.008 279 23.25 0.07 0.014 ( 0.134) 0.006 0.008 280 23.33 0.07 0.014 ( 0.133) 0.006 0.008 281 23.42 0.07 0.014 ( 0.133) 0.006 0.008 282 23.50 0.07 0.014 ( 0.133) 0.006 0.008 283 23.58 0.07 0.014 ( 0.133) 0.006 0.008 284 23.67 0.07 0.014 ( 0.133) 0.006 0.008 285 23.75 0.07 0.014 ( 0.132) 0.006 0.008 286 23.83 0.07 0.014 ( 0.132) 0.006 0.008 287 23.92 0.07 0.014 ( 0.132) 0.006 0.008 288 24.00 0.07 0.014 ( 0.132) 0.006 0.008 (Loss Rate Not Used)
Sum = 100.0 Sum = 12.5 Flood volume = Effective rainfall 1.04(In)
times area 7.0(Ac.)/[(In)/(Ft.)] = 0.6(Ac.Ft) Total soil loss = 0.76(In)
Total soil loss = 0.441(Ac.Ft)
Total rainfall = 1.80(In)
Flood volume = 26527.7 Cubic Feet
Total soil loss = 19209.7 Cubic Feet
-------------------------------------------------------------------- Peak flow rate of this hydrograph = 1.002(CFS)
-------------------------------------------------------------------- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 24 - H O U R S T O R M
R u n o f f H y d r o g r a p h
-------------------------------------------------------------------- Hydrograph in 5 Minute intervals ((CFS))
-------------------------------------------------------------------- Time(h+m) Volume Ac.Ft Q(CFS) 0 2.5 5.0 7.5 10.0 ----------------------------------------------------------------------- 0+ 5 0.0002 0.03 Q | | | | 0+10 0.0006 0.05 Q | | | | 0+15 0.0010 0.06 Q | | | | 0+20 0.0015 0.08 Q | | | | 0+25 0.0021 0.09 Q | | | | 0+30 0.0027 0.09 Q | | | | 0+35 0.0033 0.09 Q | | | | 0+40 0.0040 0.09 Q | | | | 0+45 0.0046 0.09 Q | | | | 0+50 0.0053 0.10 Q | | | | 0+55 0.0061 0.12 Q | | | | 1+ 0 0.0069 0.12 Q | | | | 1+ 5 0.0076 0.10 Q | | | | 1+10 0.0082 0.09 Q | | | | 1+15 0.0088 0.09 Q | | | | 1+20 0.0094 0.09 Q | | | | 1+25 0.0100 0.09 Q | | | | 1+30 0.0106 0.09 Q | | | | 1+35 0.0113 0.09 Q | | | | 1+40 0.0119 0.09 Q | | | | 1+45 0.0125 0.09 Q | | | | 1+50 0.0132 0.10 Q | | | | PRO 2YR24HR Page 6 of 9
1+55 0.0140 0.12 Q | | | | 2+ 0 0.0148 0.12 Q | | | | 2+ 5 0.0156 0.12 QV | | | | 2+10 0.0164 0.12 QV | | | | 2+15 0.0172 0.12 QV | | | | 2+20 0.0181 0.12 QV | | | | 2+25 0.0189 0.12 QV | | | | 2+30 0.0197 0.12 QV | | | | 2+35 0.0206 0.13 QV | | | | 2+40 0.0216 0.15 QV | | | | 2+45 0.0226 0.15 QV | | | | 2+50 0.0236 0.15 QV | | | | 2+55 0.0247 0.15 QV | | | | 3+ 0 0.0257 0.15 QV | | | | 3+ 5 0.0267 0.15 QV | | | | 3+10 0.0277 0.15 QV | | | | 3+15 0.0287 0.15 QV | | | | 3+20 0.0297 0.15 QV | | | | 3+25 0.0307 0.15 Q V | | | | 3+30 0.0318 0.15 Q V | | | | 3+35 0.0328 0.15 Q V | | | | 3+40 0.0338 0.15 Q V | | | | 3+45 0.0348 0.15 Q V | | | | 3+50 0.0359 0.16 Q V | | | | 3+55 0.0371 0.17 Q V | | | | 4+ 0 0.0384 0.18 Q V | | | | 4+ 5 0.0396 0.18 Q V | | | | 4+10 0.0408 0.18 Q V | | | | 4+15 0.0420 0.18 Q V | | | | 4+20 0.0433 0.19 Q V | | | | 4+25 0.0447 0.20 Q V | | | | 4+30 0.0462 0.21 Q V | | | | 4+35 0.0476 0.21 Q V | | | | 4+40 0.0490 0.21 Q V | | | | 4+45 0.0504 0.21 Q V | | | | 4+50 0.0520 0.22 Q V | | | | 4+55 0.0536 0.23 Q V | | | | 5+ 0 0.0552 0.24 Q V | | | | 5+ 5 0.0566 0.20 Q V | | | | 5+10 0.0578 0.18 Q V | | | | 5+15 0.0591 0.18 Q V | | | | 5+20 0.0604 0.19 Q V | | | | 5+25 0.0618 0.20 Q V | | | | 5+30 0.0632 0.21 Q V | | | | 5+35 0.0647 0.22 Q V | | | | 5+40 0.0664 0.23 Q V | | | | 5+45 0.0680 0.24 Q V | | | | 5+50 0.0696 0.24 Q V | | | | 5+55 0.0712 0.24 Q V | | | | 6+ 0 0.0729 0.24 Q V | | | | 6+ 5 0.0746 0.25 |Q V | | | | 6+10 0.0764 0.26 |Q V | | | | 6+15 0.0782 0.27 |Q V | | | | 6+20 0.0801 0.27 |Q V | | | | 6+25 0.0819 0.27 |Q V | | | | 6+30 0.0837 0.27 |Q V | | | | 6+35 0.0857 0.28 |Q V | | | | 6+40 0.0877 0.29 |Q V | | | | 6+45 0.0897 0.29 |Q V | | | | 6+50 0.0917 0.29 |Q V | | | | 6+55 0.0938 0.29 |Q V | | | | 7+ 0 0.0958 0.29 |Q V | | | | 7+ 5 0.0978 0.29 |Q V | | | | 7+10 0.0998 0.29 |Q V | | | | 7+15 0.1019 0.29 |Q V | | | | 7+20 0.1040 0.31 |Q V | | | | 7+25 0.1062 0.32 |Q V | | | | 7+30 0.1085 0.32 |Q V | | | | 7+35 0.1108 0.34 |Q V | | | | 7+40 0.1132 0.35 |Q V | | | | 7+45 0.1157 0.35 |Q V | | | | 7+50 0.1182 0.37 |Q V | | | | 7+55 0.1209 0.38 |Q V | | | | 8+ 0 0.1235 0.38 |Q V | | | | 8+ 5 0.1264 0.42 |Q V | | | | 8+10 0.1294 0.44 |Q V | | | | 8+15 0.1324 0.44 |Q V | | | | 8+20 0.1355 0.44 |Q V | | | | 8+25 0.1385 0.44 |Q V| | | | 8+30 0.1416 0.44 |Q V| | | | 8+35 0.1447 0.46 |Q V| | | | 8+40 0.1479 0.47 |Q V| | | | 8+45 0.1512 0.47 |Q V| | | | 8+50 0.1546 0.49 |Q V | | | 8+55 0.1580 0.50 |Q V | | | 9+ 0 0.1614 0.50 | Q V | | | PRO 2YR24HR Page 7 of 9
9+ 5 0.1651 0.53 | Q V | | | 9+10 0.1689 0.56 | Q |V | | | 9+15 0.1728 0.56 | Q |V | | | 9+20 0.1768 0.58 | Q |V | | | 9+25 0.1808 0.59 | Q |V | | | 9+30 0.1849 0.59 | Q | V | | | 9+35 0.1891 0.61 | Q | V | | | 9+40 0.1933 0.62 | Q | V | | | 9+45 0.1976 0.62 | Q | V | | | 9+50 0.2019 0.64 | Q | V | | | 9+55 0.2064 0.65 | Q | V | | | 10+ 0 0.2109 0.65 | Q | V | | | 10+ 5 0.2145 0.53 | Q | V | | | 10+10 0.2177 0.46 |Q | V | | | 10+15 0.2207 0.44 |Q | V | | | 10+20 0.2238 0.44 |Q | V | | | 10+25 0.2268 0.44 |Q | V | | | 10+30 0.2299 0.44 |Q | V | | | 10+35 0.2335 0.52 | Q | V | | | 10+40 0.2375 0.58 | Q | V | | | 10+45 0.2415 0.59 | Q | V | | | 10+50 0.2456 0.59 | Q | V | | | 10+55 0.2496 0.59 | Q | V | | | 11+ 0 0.2537 0.59 | Q | V | | | 11+ 5 0.2576 0.57 | Q | V | | | 11+10 0.2615 0.56 | Q | V | | | 11+15 0.2654 0.56 | Q | V | | | 11+20 0.2692 0.56 | Q | V | | | 11+25 0.2731 0.56 | Q | V | | | 11+30 0.2769 0.56 | Q | V | | | 11+35 0.2806 0.53 | Q | V | | | 11+40 0.2841 0.51 | Q | V | | | 11+45 0.2875 0.50 | Q | V | | | 11+50 0.2911 0.52 | Q | V| | | 11+55 0.2947 0.53 | Q | V| | | 12+ 0 0.2984 0.53 | Q | V| | | 12+ 5 0.3028 0.65 | Q | V| | | 12+10 0.3078 0.72 | Q | V | | 12+15 0.3129 0.74 | Q | V | | 12+20 0.3180 0.75 | Q | V | | 12+25 0.3233 0.76 | Q | |V | | 12+30 0.3286 0.77 | Q | |V | | 12+35 0.3341 0.80 | Q | |V | | 12+40 0.3397 0.82 | Q | | V | | 12+45 0.3454 0.83 | Q | | V | | 12+50 0.3512 0.84 | Q | | V | | 12+55 0.3571 0.85 | Q | | V | | 13+ 0 0.3630 0.85 | Q | | V | | 13+ 5 0.3694 0.94 | Q | | V | | 13+10 0.3763 0.99 | Q | | V | | 13+15 0.3832 1.00 | Q | | V | | 13+20 0.3901 1.00 | Q | | V | | 13+25 0.3970 1.00 | Q | | V | | 13+30 0.4039 1.00 | Q | | V | | 13+35 0.4095 0.82 | Q | | V | | 13+40 0.4144 0.70 | Q | | V | | 13+45 0.4190 0.68 | Q | | V | | 13+50 0.4237 0.68 | Q | | V | | 13+55 0.4284 0.68 | Q | | V | | 14+ 0 0.4330 0.68 | Q | | V | | 14+ 5 0.4382 0.74 | Q | | V | | 14+10 0.4436 0.79 | Q | | V| | 14+15 0.4491 0.80 | Q | | V| | 14+20 0.4544 0.78 | Q | | V| | 14+25 0.4597 0.77 | Q | | V | 14+30 0.4650 0.77 | Q | | V | 14+35 0.4703 0.77 | Q | | V | 14+40 0.4756 0.77 | Q | | |V | 14+45 0.4808 0.77 | Q | | |V | 14+50 0.4860 0.75 | Q | | |V | 14+55 0.4911 0.74 | Q | | | V | 15+ 0 0.4962 0.74 | Q | | | V | 15+ 5 0.5011 0.72 | Q | | | V | 15+10 0.5060 0.71 | Q | | | V | 15+15 0.5109 0.71 | Q | | | V | 15+20 0.5156 0.69 | Q | | | V | 15+25 0.5203 0.68 | Q | | | V | 15+30 0.5250 0.68 | Q | | | V | 15+35 0.5292 0.61 | Q | | | V | 15+40 0.5331 0.57 | Q | | | V | 15+45 0.5370 0.56 | Q | | | V | 15+50 0.5408 0.56 | Q | | | V | 15+55 0.5447 0.56 | Q | | | V | 16+ 0 0.5486 0.56 | Q | | | V | 16+ 5 0.5507 0.31 |Q | | | V | 16+10 0.5517 0.15 Q | | | V | PRO 2YR24HR Page 8 of 9
16+15 0.5525 0.12 Q | | | V | 16+20 0.5534 0.12 Q | | | V | 16+25 0.5542 0.12 Q | | | V | 16+30 0.5550 0.12 Q | | | V | 16+35 0.5557 0.10 Q | | | V | 16+40 0.5563 0.09 Q | | | V | 16+45 0.5569 0.09 Q | | | V | 16+50 0.5575 0.09 Q | | | V | 16+55 0.5581 0.09 Q | | | V | 17+ 0 0.5587 0.09 Q | | | V | 17+ 5 0.5596 0.12 Q | | | V | 17+10 0.5606 0.14 Q | | | V | 17+15 0.5616 0.15 Q | | | V | 17+20 0.5626 0.15 Q | | | V | 17+25 0.5636 0.15 Q | | | V | 17+30 0.5646 0.15 Q | | | V | 17+35 0.5656 0.15 Q | | | V | 17+40 0.5667 0.15 Q | | | V | 17+45 0.5677 0.15 Q | | | V | 17+50 0.5686 0.13 Q | | | V | 17+55 0.5694 0.12 Q | | | V | 18+ 0 0.5702 0.12 Q | | | V | 18+ 5 0.5710 0.12 Q | | | V | 18+10 0.5718 0.12 Q | | | V | 18+15 0.5726 0.12 Q | | | V | 18+20 0.5735 0.12 Q | | | V | 18+25 0.5743 0.12 Q | | | V | 18+30 0.5751 0.12 Q | | | V | 18+35 0.5758 0.10 Q | | | V | 18+40 0.5764 0.09 Q | | | V | 18+45 0.5770 0.09 Q | | | V | 18+50 0.5775 0.07 Q | | | V | 18+55 0.5779 0.06 Q | | | V | 19+ 0 0.5783 0.06 Q | | | V | 19+ 5 0.5789 0.08 Q | | | V | 19+10 0.5794 0.09 Q | | | V | 19+15 0.5801 0.09 Q | | | V | 19+20 0.5808 0.10 Q | | | V | 19+25 0.5816 0.12 Q | | | V | 19+30 0.5824 0.12 Q | | | V | 19+35 0.5831 0.10 Q | | | V | 19+40 0.5837 0.09 Q | | | V | 19+45 0.5843 0.09 Q | | | V | 19+50 0.5848 0.07 Q | | | V | 19+55 0.5852 0.06 Q | | | V | 20+ 0 0.5856 0.06 Q | | | V | 20+ 5 0.5862 0.08 Q | | | V | 20+10 0.5868 0.09 Q | | | V | 20+15 0.5874 0.09 Q | | | V | 20+20 0.5880 0.09 Q | | | V | 20+25 0.5886 0.09 Q | | | V | 20+30 0.5892 0.09 Q | | | V | 20+35 0.5898 0.09 Q | | | V | 20+40 0.5904 0.09 Q | | | V | 20+45 0.5910 0.09 Q | | | V | 20+50 0.5915 0.07 Q | | | V | 20+55 0.5919 0.06 Q | | | V | 21+ 0 0.5923 0.06 Q | | | V | 21+ 5 0.5929 0.08 Q | | | V | 21+10 0.5935 0.09 Q | | | V | 21+15 0.5941 0.09 Q | | | V| 21+20 0.5946 0.07 Q | | | V| 21+25 0.5950 0.06 Q | | | V| 21+30 0.5954 0.06 Q | | | V| 21+35 0.5959 0.08 Q | | | V| 21+40 0.5965 0.09 Q | | | V| 21+45 0.5971 0.09 Q | | | V| 21+50 0.5976 0.07 Q | | | V| 21+55 0.5980 0.06 Q | | | V| 22+ 0 0.5984 0.06 Q | | | V| 22+ 5 0.5989 0.08 Q | | | V| 22+10 0.5995 0.09 Q | | | V| 22+15 0.6002 0.09 Q | | | V| 22+20 0.6007 0.07 Q | | | V| 22+25 0.6011 0.06 Q | | | V| 22+30 0.6015 0.06 Q | | | V| 22+35 0.6019 0.06 Q | | | V| 22+40 0.6023 0.06 Q | | | V| 22+45 0.6027 0.06 Q | | | V| 22+50 0.6031 0.06 Q | | | V| 22+55 0.6035 0.06 Q | | | V| 23+ 0 0.6039 0.06 Q | | | V| 23+ 5 0.6043 0.06 Q | | | V| 23+10 0.6047 0.06 Q | | | V| 23+15 0.6051 0.06 Q | | | V| 23+20 0.6055 0.06 Q | | | V| PRO 2YR24HR Page 9 of 9
23+25 0.6059 0.06 Q | | | V| 23+30 0.6063 0.06 Q | | | V| 23+35 0.6068 0.06 Q | | | V| 23+40 0.6072 0.06 Q | | | V| 23+45 0.6076 0.06 Q | | | V| 23+50 0.6080 0.06 Q | | | V| 23+55 0.6084 0.06 Q | | | V| 24+ 0 0.6088 0.06 Q | | | V| 24+ 5 0.6090 0.03 Q | | | V| 24+10 0.6090 0.00 Q | | | V| ----------------------------------------------------------------------- - 34 -

Appendix 8: Source Control
Pollutant Sources/Source Control Checklist

STORMWATER POLLUTANT SOURCES/SOURCE CONTROL CHECKLIST

How to use this worksheet (also see instructions in Section G of the WQMP Template):

1. Review Column 1 and identify which of these potential sources of stormwater pollutants apply to your site. Check each box that applies.

2. Review Column 2 and incorporate all of the corresponding applicable BMPs in your WQMP Exhibit.

3. Review Columns 3 and 4 and incorporate all of the corresponding applicable permanent controls and operational BMPs in your WQMP. Use the format shown in Table G.1on page 23 of this WQMP Template. Describe your specific BMPs in an accompanying narrative, and explain any special conditions or situations that required omitting BMPs or substituting alternative BMPs for those shown here.

IF THESE SOURCES WILL BE
ON THE PROJECT SITE … … THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE 1 Potential Sources of
Runoff Pollutants
2 Permanent Controls—Show on
WQMP Drawings
3 Permanent Controls—List in WQMP
Table and Narrative
4 Operational BMPs—Include in WQMP
Table and Narrative
 A. On-site storm drain
inlets
 Locations of inlets.  Mark all inlets with the words “Only Rain Down the Storm
Drain” or similar. Catch Basin
Markers may be available from the
Riverside County Flood Control
and Water Conservation District,
call 951.955.1200 to verify.







Maintain and periodically repaint or
replace inlet markings.

Provide stormwater pollution
prevention information to new site
owners, lessees, or operators.

See applicable operational BMPs in
Fact Sheet SC-44, “Drainage System
Maintenance,” in the CASQA
Stormwater Quality Handbooks at
www.cabmphandbooks.com
Include the following in lease
agreements: “Tenant shall not allow
anyone to discharge anything to storm
drains or to store or deposit materials
so as to create a potential discharge to
storm drains.”
 B. Interior floor drains
and elevator shaft sump
pumps
 State that interior floor drains and
elevator shaft sump pumps will be
plumbed to sanitary sewer.
 Inspect and maintain drains to prevent
blockages and overflow.
 C. Interior parking
garages
 State that parking garage floor
drains will be plumbed to the
sanitary sewer.
 Inspect and maintain drains to prevent
blockages and overflow.

STORMWATER POLLUTANT SOURCES/SOURCE CONTROL CHECKLIST

IF THESE SOURCES WILL BE
ON THE PROJECT SITE … … THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE 1 Potential Sources of
Runoff Pollutants
2 Permanent Controls—Show on
WQMP Drawings
3 Permanent Controls—List in WQMP
Table and Narrative
4 Operational BMPs—Include in WQMP
Table and Narrative
 D1. Need for future
indoor & structural pest
control
 Note building design features that
discourage entry of pests.
 Provide Integrated Pest Management
information to owners, lessees, and
operators.
 D2. Landscape/
Outdoor Pesticide Use





Show locations of native trees or
areas of shrubs and ground cover to
be undisturbed and retained.

Show self-retaining landscape
areas, if any.

Show stormwater treatment and
hydrograph modification
management BMPs. (See
instructions in Chapter 3, Step 5
and guidance in Chapter 5.)











State that final landscape plans will
accomplish all of the following.

Preserve existing native trees,
shrubs, and ground cover to the
maximum extent possible.

Design landscaping to minimize
irrigation and runoff, to promote
surface infiltration where
appropriate, and to minimize the
use of fertilizers and pesticides that
can contribute to stormwater
pollution.

Where landscaped areas are used to
retain or detain stormwater, specify
plants that are tolerant of saturated
soil conditions.

Consider using pest-resistant
plants, especially adjacent to
hardscape.

To insure successful establishment,
select plants appropriate to site
soils, slopes, climate, sun, wind,
rain, land use, air movement,
ecological consistency, and plant
interactions.





Maintain landscaping using minimum
or no pesticides.

See applicable operational BMPs in
“What you should know
for…..Landscape and Gardening” at
http://rcflood.org/stormwater/Error!
Hyperlink reference not valid.

Provide IPM information to new
owners, lessees and operators.

STORMWATER POLLUTANT SOURCES/SOURCE CONTROL CHECKLIST

IF THESE SOURCES WILL BE
ON THE PROJECT SITE … … THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE 1 Potential Sources of
Runoff Pollutants
2 Permanent Controls—Show on
WQMP Drawings
3 Permanent Controls—List in WQMP
Table and Narrative
4 Operational BMPs—Include in WQMP
Table and Narrative
 E. Pools, spas, ponds,
decorative fountains,
and other water
features.
 Show location of water feature and
a sanitary sewer cleanout in an
accessible area within 10 feet.
(Exception: Public pools must be
plumbed according to County
Department of Environmental
Health Guidelines.)
If the Co-Permittee requires pools
to be plumbed to the sanitary
sewer, place a note on the plans
and state in the narrative that this
connection will be made according
to local requirements.
 See applicable operational BMPs in
“Guidelines for Maintaining Your
Swimming Pool, Jacuzzi and Garden
Fountain” at
http://rcflood.org/stormwater/
 F. Food service 


For restaurants, grocery stores, and
other food service operations, show
location (indoors or in a covered
area outdoors) of a floor sink or
other area for cleaning floor mats,
containers, and equipment.

On the drawing, show a note that
this drain will be connected to a
grease interceptor before
discharging to the sanitary sewer.



Describe the location and features
of the designated cleaning area.

Describe the items to be cleaned in
this facility and how it has been
sized to insure that the largest
items can be accommodated.

 See the brochure, “The Food Service
Industry Best Management Practices for:

Restaurants, Grocery Stores,
Delicatessens and Bakeries” at
http://rcflood.org/stormwater/
Provide this brochure to new site
owners, lessees, and operators.
 G. Refuse areas 




Show where site refuse and
recycled materials will be handled
and stored for pickup. See local
municipal requirements for sizes
and other details of refuse areas.

If dumpsters or other receptacles
are outdoors, show how the
designated area will be covered,
graded, and paved to prevent run-
on and show locations of berms to
prevent runoff from the area.

Any drains from dumpsters,
compactors, and tallow bin areas
shall be connected to a grease
removal device before discharge to
sanitary sewer.



State how site refuse will be
handled and provide supporting
detail to what is shown on plans.

State that signs will be posted on or
near dumpsters with the words “Do
not dump hazardous materials
here” or similar.
 State how the following will be
implemented:

Provide adequate number of
receptacles. Inspect receptacles
regularly; repair or replace leaky
receptacles. Keep receptacles covered.

Prohibit/prevent dumping of liquid or
hazardous wastes. Post “no hazardous
materials” signs. Inspect and pick up
litter daily and clean up spills
immediately. Keep spill control
materials available on-site. See Fact
Sheet SC-34, “Waste Handling and
Disposal” in the CASQA Stormwater
Quality Handbooks at
www.cabmphandbooks.com

STORMWATER POLLUTANT SOURCES/SOURCE CONTROL CHECKLIST

IF THESE SOURCES WILL BE
ON THE PROJECT SITE … … THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE 1 Potential Sources of
Runoff Pollutants
2 Permanent Controls—Show on
WQMP Drawings
3 Permanent Controls—List in WQMP
Table and Narrative
4 Operational BMPs—Include in WQMP
Table and Narrative
 H. Industrial processes.  Show process area.  If industrial processes are to be located on site, state: “All process
activities to be performed indoors.

No processes to drain to exterior or
to storm drain system.”
 See Fact Sheet SC-10, “Non-
Stormwater Discharges” in the
CASQA Stormwater Quality
Handbooks at
www.cabmphandbooks.com
See the brochure “Industrial &
Commercial Facilities Best Management
Practices for: Industrial, Commercial
Facilities” at
http://rcflood.org/stormwater/

STORMWATER POLLUTANT SOURCES/SOURCE CONTROL CHECKLIST

IF THESE SOURCES WILL BE
ON THE PROJECT SITE … … THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE 1 Potential Sources of
Runoff Pollutants
2 Permanent Controls—Show on
WQMP Drawings
3 Permanent Controls—List in WQMP
Table and Narrative
4 Operational BMPs—Include in WQMP
Table and Narrative
 I. Outdoor storage of
equipment or materials.
(See rows J and K for
source control
measures for vehicle
cleaning, repair, and
maintenance.)






Show any outdoor storage areas,
including how materials will be
covered. Show how areas will be
graded and bermed to prevent run-
on or run-off from area.

Storage of non-hazardous liquids
shall be covered by a roof and/or
drain to the sanitary sewer system,
and be contained by berms, dikes,
liners, or vaults.

Storage of hazardous materials and
wastes must be in compliance with
the local hazardous materials
ordinance and a Hazardous
Materials Management Plan for the
site.

Include a detailed description of
materials to be stored, storage
areas, and structural features to
prevent pollutants from entering
storm drains.

Where appropriate, reference
documentation of compliance with
the requirements of Hazardous
Materials Programs for:
 Hazardous Waste Generation
 Hazardous Materials Release
Response and Inventory
 California Accidental Release
(CalARP)
 Aboveground Storage Tank
 Uniform Fire Code Article 80
Section 103(b) & (c) 1991
 Underground Storage Tank
www.cchealth.org/groups/hazmat
/

 See the Fact Sheets SC-31, “Outdoor
Liquid Container Storage” and SC-33,
“Outdoor Storage of Raw Materials ”
in the CASQA Stormwater Quality
Handbooks at
www.cabmphandbooks.com

STORMWATER POLLUTANT SOURCES/SOURCE CONTROL CHECKLIST

IF THESE SOURCES WILL BE
ON THE PROJECT SITE … … THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE 1 Potential Sources of
Runoff Pollutants
2 Permanent Controls—Show on
WQMP Drawings
3 Permanent Controls—List in WQMP
Table and Narrative
4 Operational BMPs—Include in WQMP
Table and Narrative
 J. Vehicle and
Equipment Cleaning
 Show on drawings as appropriate:
(1) Commercial/industrial facilities
having vehicle/equipment cleaning
needs shall either provide a
covered, bermed area for washing
activities or discourage
vehicle/equipment washing by
removing hose bibs and installing
signs prohibiting such uses.
(2) Multi-dwelling complexes shall
have a paved, bermed, and covered
car wash area (unless car washing
is prohibited on-site and hoses are
provided with an automatic shut-
off to discourage such use).
(3) Washing areas for cars, vehicles,
and equipment shall be paved,
designed to prevent run-on to or
runoff from the area, and plumbed
to drain to the sanitary sewer.
(4) Commercial car wash facilities
shall be designed such that no
runoff from the facility is
discharged to the storm drain
system. Wastewater from the
facility shall discharge to the
sanitary sewer, or a wastewater
reclamation system shall be
installed.
 If a car wash area is not provided,
describe any measures taken to
discourage on-site car washing and
explain how these will be enforced.



Describe operational measures to
implement the following (if
applicable):

Washwater from vehicle and
equipment washing operations shall
not be discharged to the storm drain
system. Refer to “Outdoor Cleaning
Activities and Professional Mobile Service
Providers” for many of the Potential
Sources of Runoff Pollutants categories
below. Brochure can be found at
http://rcflood.org/stormwater/
Car dealerships and similar may
rinse cars with water only.

STORMWATER POLLUTANT SOURCES/SOURCE CONTROL CHECKLIST

IF THESE SOURCES WILL BE
ON THE PROJECT SITE … … THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE 1 Potential Sources of
Runoff Pollutants
2 Permanent Controls—Show on
WQMP Drawings
3 Permanent Controls—List in WQMP
Table and Narrative
4 Operational BMPs—Include in WQMP
Table and Narrative
 K. Vehicle/Equipment
Repair and
Maintenance






Accommodate all vehicle
equipment repair and maintenance
indoors. Or designate an outdoor
work area and design the area to
prevent run-on and runoff of
stormwater.

Show secondary containment for
exterior work areas where motor
oil, brake fluid, gasoline, diesel
fuel, radiator fluid, acid-containing
batteries or other hazardous
materials or hazardous wastes are
used or stored. Drains shall not be
installed within the secondary
containment areas.

Add a note on the plans that states
either (1) there are no floor drains,
or (2) floor drains are connected to
wastewater pretreatment systems
prior to discharge to the sanitary
sewer and an industrial waste
discharge permit will be obtained.





State that no vehicle repair or
maintenance will be done outdoors,
or else describe the required
features of the outdoor work area.

State that there are no floor drains
or if there are floor drains, note the
agency from which an industrial
waste discharge permit will be
obtained and that the design meets
that agency’s requirements.

State that there are no tanks,
containers or sinks to be used for
parts cleaning or rinsing or, if there
are, note the agency from which an
industrial waste discharge permit
will be obtained and that the
design meets that agency’s
requirements.






In the Stormwater Control Plan, note
that all of the following restrictions
apply to use the site:

No person shall dispose of, nor permit
the disposal, directly or indirectly of
vehicle fluids, hazardous materials, or
rinsewater from parts cleaning into
storm drains.

No vehicle fluid removal shall be
performed outside a building, nor on
asphalt or ground surfaces, whether
inside or outside a building, except in
such a manner as to ensure that any
spilled fluid will be in an area of
secondary containment. Leaking
vehicle fluids shall be contained or
drained from the vehicle immediately.

No person shall leave unattended drip
parts or other open containers
containing vehicle fluid, unless such
containers are in use or in an area of
secondary containment.

Refer to “Automotive Maintenance & Car
Care Best Management Practices for Auto
Body Shops, Auto Repair Shops, Car
Dealerships, Gas Stations and Fleet
Service Operations”. Brochure can be
found at http://rcflood.org/stormwater/
Refer to Outdoor Cleaning Activities and
Professional Mobile Service Providers for
many of the Potential Sources of
Runoff Pollutants categories below.

Brochure can be found at
http://rcflood.org/stormwater/

STORMWATER POLLUTANT SOURCES/SOURCE CONTROL CHECKLIST

IF THESE SOURCES WILL BE
ON THE PROJECT SITE … … THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE 1 Potential Sources of
Runoff Pollutants
2 Permanent Controls—Show on
WQMP Drawings
3 Permanent Controls—List in WQMP
Table and Narrative
4 Operational BMPs—Include in WQMP
Table and Narrative
 L. Fuel Dispensing
Areas



Fueling areas6 shall have
impermeable floors (i.e., portland
cement concrete or equivalent
smooth impervious surface) that
are: a) graded at the minimum
slope necessary to prevent ponding;
and b) separated from the rest of
the site by a grade break that
prevents run-on of stormwater to
the maximum extent practicable.

Fueling areas shall be covered by a
canopy that extends a minimum of
ten feet in each direction from each
pump. [Alternative: The fueling
area must be covered and the
cover’s minimum dimensions must
be equal to or greater than the area
within the grade break or fuel
dispensing area1.] The canopy [or
cover] shall not drain onto the
fueling area.



The property owner shall dry sweep
the fueling area routinely.

See the Fact Sheet SD-30 , “Fueling
Areas” in the CASQA Stormwater
Quality Handbooks at
www.cabmphandbooks.com

6 The fueling area shall be defined as the area extending a minimum of 6.5 feet from the corner of each fuel dispenser or the length at which the hose and nozzle assembly may be operated plus a minimum of one foot, whichever is greater.

STORMWATER POLLUTANT SOURCES/SOURCE CONTROL CHECKLIST

IF THESE SOURCES WILL BE
ON THE PROJECT SITE … … THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE 1 Potential Sources of
Runoff Pollutants
2 Permanent Controls—Show on
WQMP Drawings
3 Permanent Controls—List in WQMP
Table and Narrative
4 Operational BMPs—Include in WQMP
Table and Narrative
 M. Loading Docks 




Show a preliminary design for the
loading dock area, including
roofing and drainage. Loading
docks shall be covered and/or
graded to minimize run-on to and
runoff from the loading area. Roof
downspouts shall be positioned to
direct stormwater away from the
loading area. Water from loading
dock areas shall be drained to the
sanitary sewer, or diverted and
collected for ultimate discharge to
the sanitary sewer.

Loading dock areas draining
directly to the sanitary sewer shall
be equipped with a spill control
valve or equivalent device, which
shall be kept closed during periods
of operation.

Provide a roof overhang over the
loading area or install door skirts
(cowling) at each bay that enclose
the end of the trailer.



Move loaded and unloaded items
indoors as soon as possible.

See Fact Sheet SC-30, “Outdoor
Loading and Unloading,” in the
CASQA Stormwater Quality
Handbooks at
www.cabmphandbooks.com

STORMWATER POLLUTANT SOURCES/SOURCE CONTROL CHECKLIST

IF THESE SOURCES WILL BE
ON THE PROJECT SITE … … THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE 1 Potential Sources of
Runoff Pollutants
2 Permanent Controls—Show on
WQMP Drawings
3 Permanent Controls—List in WQMP
Table and Narrative
4 Operational BMPs—Include in WQMP
Table and Narrative
 N. Fire Sprinkler Test
Water
 Provide a means to drain fire
sprinkler test water to the sanitary
sewer.
 See the note in Fact Sheet SC-41,
“Building and Grounds Maintenance,”
in the CASQA Stormwater Quality
Handbooks at
www.cabmphandbooks.com








O. Miscellaneous Drain
or Wash Water or Other
Sources
Boiler drain lines
Condensate drain lines
Rooftop equipment
Drainage sumps
Roofing, gutters, and
trim.

Other sources











Boiler drain lines shall be directly
or indirectly connected to the
sanitary sewer system and may not
discharge to the storm drain
system.

Condensate drain lines may
discharge to landscaped areas if the
flow is small enough that runoff
will not occur. Condensate drain
lines may not discharge to the
storm drain system.

Rooftop equipment with potential
to produce pollutants shall be
roofed and/or have secondary
containment.

Any drainage sumps on-site shall
feature a sediment sump to reduce
the quantity of sediment in
pumped water.

Avoid roofing, gutters, and trim
made of copper or other
unprotected metals that may leach
into runoff.

Include controls for other sources
as specified by local reviewer.

STORMWATER POLLUTANT SOURCES/SOURCE CONTROL CHECKLIST

IF THESE SOURCES WILL BE
ON THE PROJECT SITE … … THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE 1 Potential Sources of
Runoff Pollutants
2 Permanent Controls—Show on
WQMP Drawings
3 Permanent Controls—List in WQMP
Table and Narrative
4 Operational BMPs—Include in WQMP
Table and Narrative
 P. Plazas, sidewalks,
and parking lots.
 Sweep plazas, sidewalks, and parking
lots regularly to prevent accumulation
of litter and debris. Collect debris from
pressure washing to prevent entry into
the storm drain system. Collect
washwater containing any cleaning
agent or degreaser and discharge to
the sanitary sewer not to a storm drain.

- 35 -

Appendix 9: O&M
Operation and Maintenance Plan and Documentation of Finance, Maintenance and Recording Mechanisms

Water Quality Management Plan (WQMP)
River Pointe
Riverside

Property Owner
Beazer Homes, 310 Commerce Street Irvine, CA 92602 – (949) 333-9592 Operations & Maintenance Responsibility for Treatment Control BMP’s

BMP Required
Maintenance
Frequency Maintenance Requirements Responsibility
Trash Weekly Empty Dumpsters Property Owner
Roof Drains/
Gutters
Before wet
season, or
significant rain
event, or when
needed
Roof Gutters shall be visually inspected for defects and possible leakage. Damage or defects found shall be
corrected as soon as possible.

Owners should avoid use of gutters, roofing, and trim made of copper so as to prevent the metal from leaching into runoff.

Property Owner

INFILTRATION
BASIN

Bi-Weekly

Semi-Annual

Annually

As Needed
Mow, weed, trim and remove accumulation of trash debris and/or sediment. Routine inspections for areas of standing water within the BMP and corrective measures to restore proper infiltration rates are necessary.

Trim Vegetation at the beginning and end of the wet season to prevent establishment of woody vegetation. Replant
eroded or barren spots to prevent erosion and accumulation of sediment.

Per Condition of Approval 90.FLOODRI all BMPs are to
be inspected, and if required, cleaned no later than October 15 each year

Stabilize eroded banks, repair undercut and eroded areas at inflow and outflow areas, maintain access to the basin for regular maintenance, mow as appropriate for vegetative
cover species, monitor health of vegetation and replace as necessary, control mosquitos as necessary, remove liter and debris. Mulch replacement may be necessary on an
occasional basis to fill in voids, mulching should be done prior to the wet season. Unclog underdrain, and regulate soil pH.

For additional maintenance information please see
Appendix 10 of the WQMP
Grading Plans and BMP Map provided in WQMP
document provide additional information on location of
Bio-retention facility and tributary areas.

Home Owners
Association

Self-Retaining/
Landscape Areas

Bi-Weekly Mow, weed, trim and remove accumulation of trash debris and/or sediment. Retaining areas should be mowed at 4-6 inches in height if grass is proposed.

Maintain landscaping using minimal pesticides

Home Owners
Association
BMP's should start and be inspected prior to forecast rain, daily during extended rain events, after rain events, weekly during the rainy season, and at two-week intervals during the non-rainy season.

Water Quality Management Plan (WQMP)
River Pointe
Riverside

Property Owner
Beazer Homes, 310 Commerce Street Irvine, CA 92602 – (949) 333-9592 Funding
Funding for Ongoing Maintenance will be provided by the Home Owner’s Association.

Water Quality Management Plan (WQMP)
River Pointe
Riverside

Property Owner
Beazer Homes, 310 Commerce Street Irvine, CA 92602 – (949) 333-9592 Basin Site Maintenance Summary Form
Date: Inspector Name: Basin:

Maintenance Performed:

Date: Inspector Name: Basin:

Maintenance Performed:

Date: Inspector Name: Basin:

Maintenance Performed:

Date: Inspector Name: Basin:

Maintenance Performed:

Date: Inspector Name: Basin:

Maintenance Performed:

Date: Inspector Name: Basin:

Maintenance Performed:

Date: Inspector Name: Basin:

Maintenance Performed:

Date: Inspector Name: Basin:

Maintenance Performed:

Date: Inspector Name: Basin:

Maintenance Performed:

Date: Inspector Name: Basin:

Maintenance Performed:

Date: Inspector Name: Basin:

Maintenance Performed:

Date: Inspector Name: Basin:

Maintenance Performed:

Date: Inspector Name: Basin:

Maintenance Performed:

Date: Inspector Name: Basin:

Maintenance Performed:

WHEN RECORDED MAIL TO:

City Clerk
City of Riverside
City Hall, 3900 Main Street
Riverside, CA 92522

Planning Case: P__-____

For Recorder’s Office Use Only

COVENANT AND AGREEMENT

ESTABLISHING NOTIFICATION PROCESS AND RESPONSIBILITY FOR

WATER QUALITY MANAGEMENT PLAN IMPLEMENTATION AND MAINTENANCE

THIS COVENANT AND AGREEMENT FOR WATER QUALITY
MANAGEMENT PLAN IMPLEMENTATION AND MAINTENANCE is made and entered into this ______ day of __________________, 20__, by _____ {Insert Name of Owner} ______ _____________________________(“Declarant”), with reference to the following facts:

A. Declarant is the fee owner of the re al property (the "Property") situated in the City of Riverside, County of Riverside, State of California, and legally described in Exhibit “A”, which is attached hereto and incorporated within by reference.

B. Declarant has applied to the C ity of Riverside (“City”) for ____________ _________{Insert Project Description for Above Referenced Planning Case}________________ ________________________________________________________________________.

C. As a condition of approval and prior to the map recordation and/or issuance of any permits, the City is requiring Declarant to ex ecute and record an agreement stating that the future property owners shall be informed of the requirements to implement and maintain the Best Management Practices (“BMPs”) as described in the approved project specific Water Quality Management Plan.

D. Declarant intends by this document to comply with the conditions imposed by the City and to impose upon the Property mutu ally beneficial restrictions, conditions, covenants and agreements for the benefit of Property.

NOW, THEREFORE, for the purposes of complying with the conditions imposed by the City of Riverside for the approval of Planning Case P__-____, Declarant hereby declares that the Property is and hereafter shall be held, conveyed, transferred, mortgaged, encumbered, leased, rented, used, occupied, sold and im proved subject to the following declarations, limitations, covenants, conditions, restrictions and easements, all of which are imposed as

equitable servitudes pursuant to a general plan for the development of the Property for the purpose of enhancing and protecting the value and attractiveness of the Property, and each Parcel thereof, in accordance with the plan for the improvement of the Property, and to comply with certain conditions imposed by th e City for the approval of P __-____, and shall be binding and inure to the benefit of each successor and assignee in interest of each such party. Any conveyance, transfer, sale, assignment, lease or sublease made by Declarant of a Parcel of the Property shall be and hereby is d eemed to incorporate by reference all the provisions of the Covenant and Agreement including, but not limited to, all the covenants, conditions, restrictions, limitations, grants of easement, rights, rights-of-way, and equitable servitude contained herein.

1. This Covenant and Agreement he reby establishes a notification process for future individual property owners to ensure they are subject to and adhere to the Water Quality Management Plan implementation measures and that it shall be the responsibility of the Declarant, its heirs, successors and assigns to implement and maintain all Best Management Practices (BMPs) in good working order.

2. Declarant shall use its best efforts to diligently implement and maintain all BMPs in a manner assuring peak performance at all times. All reasonable precautions shall be exercised by Declarant, its heirs, successors a nd assigns, in the removal and extraction of any material(s) from the BMPs and the ultimate dis posal of the material(s) in a manner consistent with all relevant laws and regulations in effect at the time. As may be requested from time to time by the City, Declarant, its heirs, success ors and assigns shall pr ovide the City with documentation identifying the material(s) removed, the quantity, and disposal destination.

3. In the event Declarant, or its heirs, successors or assigns, fails to undertake the maintenance contemplated by this Covenant and Agreement within twenty-one (21) days of being given written notice by the City, or fails to complete any maintenance contemplated by this Covenant and Agreement with reasonable diligen ce, the City is hereby authorized to cause any maintenance necessary to be completed and charge the entire cost and expense to the Declarant or Declarant’s successors or assigns, including administrative costs, reasonable attorneys fees and interest thereon at the maximum rate author ized by the Civil Code from the date of the notice of expense until paid in full. As an additional remedy, the Public Works Director may withdraw any previous urban runoff-related approval with re spect to the Property on which BMPs have been installed and/or implemented un til such time as Declarant, its heirs, successors or assigns, repays to City its reasonable costs incurred in accordance with this paragraph.

4. Any person who now or hereafter owns or acquires any right, title or interest in or to any parcel of the Property shall be deemed to have consented and agreed to every covenant, condition, restriction and easement contained herein.

5. In addition, each of the provision s hereof shall operate as covenants running with the land for the benefit of the Property and each Parcel thereof and shall inure to the benefit of all owners of the Parcels thereof, th eir successors and assigns in interest, and shall apply to and bind each successive owner of each Parcel, their successors and assigns in interest.

6. The terms of this Covenant and Agreement may be enforced by the City, its successors or assigns, and by any owner, lessee or tenant of the Parcels of the Property.

Should the City or any owner, lessee or tenant bri ng an action to enforce any of the terms of this Covenant and Agreement, the prevailing party sh all be entitled to costs of suit including reasonable attorneys’ fees.

7. Subject to the prior written appr oval of the City by its Public Works Director, any provision contained herein may be terminated, modified or amended as to all of the Property or any portion thereof. No such te rmination, modification or amendment shall be effective until there shall have been executed, acknowledged and re corded in the Office of the Recorder of Riverside County, Ca lifornia, an appropriate inst rument evidencing the same including the consent thereto by the City.

IN WITNESS WHEREOF, Declarant has caused this Covenant and Agreement to be executed as of the day and year first written above.

___________{Insert_Name_of_Owner}__________

________________________________
Name:

Title:

___________________________________________
Name:

Title:

APPROVED AS TO FORM: APPROVED AS TO CONTENT

________________________________ _______________________________ N a m e : N a m e :

Deputy City Attorney Public Works Department:

STATE OF )
)

C O U N T Y O F )

On _____________________________, before me, ____________________________, Notary Public, personally appeared _______________________________________________, who proved to me on the basis of satisfactory eviden ce, to be the person(s) whose name(s) is/are subscribed to the within instrument and acknowle dged to me that he/she/they executed the same in his/her/their authorized capaci ty(ies), and that by his/her/thei r signature(s) on the instrument the person(s), or the entity upon behalf of which the person(s) acted, executed the instrument.

I certify under PENALTY OF PERJURY under the laws of the State of ______________ that the foregoing paragraph is true and correct.

WITNESS my hand and official seal.

(SEAL)
Notary Public Signature

STATE OF )
)

C O U N T Y O F )

On _____________________________, before me, ____________________________, Notary Public, personally appeared _______________________________________________, who proved to me on the basis of satisfactory eviden ce, to be the person(s) whose name(s) is/are subscribed to the within instrument and acknowle dged to me that he/she/they executed the same in his/her/their authorized capaci ty(ies), and that by his/her/thei r signature(s) on the instrument the person(s), or the entity upon behalf of which the person(s) acted, executed the instrument.

I certify under PENALTY OF PERJURY under the laws of the State of ______________ that the foregoing paragraph is true and correct.

WITNESS my hand and official seal.

(SEAL)
Notary Public Signature

EXHIBIT A
(Legal Description)

EXHIBIT B
(Map/Illustration)
- 36 -

Appendix 10: Educational Materials
BMP Fact Sheets, Maintenance Guidelines and Other End-User BMP Information Infiltration Basin TC-11
June 2021 California Stormwater BMP Handbook 5-89
Development
www.casqa.org

Description
An infiltration basin is a relatively large impoundment that is designed to infiltrate stormwater. Infiltration basins use the natural filtering ability of the soil to remove pollutants in stormwater runoff. Infiltration facilities store runoff until it gradually exfiltrates through the soil and eventually into the water table. This practice removes surface flow and associated pollutants through infiltration and can also help recharge groundwater, thus helping to maintain low flows in stream systems. Infiltration basins can be challenging to apply on many sites, however, because of soils requirements. In addition, some studies have shown relatively high failure rates compared with other management practices.

California Experience
Infiltration basins have a long history of use in California, especially in the Central Valley.

Basins located in Fresno were among those initially evaluated in the National Urban Runoff Program and were found to be effective at reducing the volume of runoff, while posing little long-term threat to groundwater quality (EPA, 1983; Schroeder, 1995). Proper siting of these devices is crucial as underscored by the experience of Caltrans in siting two basins in Southern California. The basin with marginal separation from groundwater and soil permeability failed immediately and could never be rehabilitated. The Water Augmentatoin Study (LASGRWC 2010) perfomred in the Los Angeles region showed no negative impact to ground water from infiltrating stormwater through infiltration practices treating stormwater from sites ranging from 0.5 acres to 7.4 acres.

Infiltration basins have been shown to be effective at reducing many of the pollutants regulated by the State and Regional Water Boards. Additionally, the Water Boards have determined that Design Considerations
 Soil for Infiltration
 Slope
 Aesthetics
Targeted
Constituent Removal
Sediment High
Nutrients High
Trash High
Metals High
Bacteria High
Oil and Grease High
Organics High
Flow Control High

Infiltration Basin TC-11
June 2021 California Stormwater BMP Handbook 5-90
Development
www.casqa.org
infiltration basins can qualify as a ”Full Capture System (FCS)1” for trash. Accordingly, in addition to providing general specifications, this fact sheet includes trash-specific information to assist with upgrading either an existing BMP or the design of a planned BMP to meet the FCS definition. See the “Full Trash Capture Compliance” section and “Trash FCS” subsections in this fact sheet for more information.

Advantages
 Provides stormwater treatment and can be designed to meet hydromodification management requirements and the full capture system definition for trash control.  100% reduction in the load discharged to surface waters.  Can achieve pre-development hydrology by infiltrating a significant portion of the average annual rainfall runoff.

Limitations
 Have a high failure rate if soil and subsurface conditions are not suitable.  May not be appropriate for industrial sites or locations where spills may occur.  Infiltration basins require a minimum soil infiltration rate of 0.5 inches/hour, not appropriate at sites with Hydrologic Soil Types C or D.

Performance
As water migrates through porous soil and rock, pollutant attenuation mechanisms include precipitation, sorption, physical filtration, and bacterial degradation (Table 1). Vegetation establishment may improve water quality performance and decrease residence time (i.e., increase water losses). If functioning properly, this approach is presumed to have high removal efficiencies for particulate pollutants and moderate removal of soluble pollutants. Actual pollutant removal in the subsurface would be expected to vary depending upon site-specific soil types. This technology eliminates discharge to surface waters except for the very largest storms; consequently, complete removal of all stormwater constituents can be assumed.

Table 1. Typical pollutant removal for constituents and removal processes Pollutant Typical
Removal
Median Effluent
Concentration1 Removal Processes Treatment
Depth References
Sediment High (90%) 9.9 mg/l Settling, filtration and
sedimentation in top 2
to 8 inches of media.

1.5 feet Geosyntec Consultants and
Wright Water Engineering 2012;
Hatt et al. 2008; Hunt et al.
2012; Li and Davis 2008;
Stander and Borst 2010;
Maniquiz, 2010; Scholes, 2007

1 Full Capture System (FCS): A treatment control, or series of treatment controls, including but not limited to, a multi-benefit projector a low impact development control that traps all particles that are 5 mm or greater, and has a design treatment capacity that is either: a) of not less than the peak flow rate, Q, resulting from a one-year, one-hour, storm in the subdrainage area, or b) appropriately sized to, and designed to carry at least the same flows as, the corresponding storm drain.

Infiltration Basin TC-11
June 2021 California Stormwater BMP Handbook 5-91
Development
www.casqa.org
Pollutant Typical
Removal
Median Effluent
Concentration1 Removal Processes Treatment
Depth References
Metals High TCd: 0.07 µg/L,
TCr: 0.35 µg/L,
TCu: 5.33 µg/L,
TFe: 1027 µg/L,
TPb: 0.19 µg/L,
TNi: 4.53 µg/L,
TZn: 12.0 µg/L
Settling with sediment
and sorption to organic
matter and clay in
media.
2 feet
Geosyntec Consultants and
Wright Water Engineering 2012;
Hsieh and Davis 2005; Hunt et al.
2012; Maniquiz, 2010
Hydro-
carbons
High (90-
97%)
N/A Volatilization, sorption,
and degradation in
mulch layer.
1 foot Hong et al. 2006; Hunt et al.
2012; Barraud et al 1999;
Dierkes and Geiger, 1999;
Mikkelsen et al. 1997; Hong et
al. 2006. Hsieh and Davis 2005;
Pitt et al. 1999
Total
phosphorus
High
(-240% to
99%)

0.240 mg/l Settling with sediment,
sorption to organic
matter and clay in
media, and plant
uptake. Poor removal
efficiency can result
from media containing
high organic matter or
with high background
concentrations of
phosphorus.
2 feet Clark and Pitt 2009; Davis 2007;
Geosyntec Consultants and
Wright Water Engineering 2012;
Hsieh and Davis 2005; Hunt et
al. 2006; Hunt and Lord 2006; Li
et al. 2010; Maniquiz 2010
Total
nitrogen
High (TKN:
-5% to
64%,
Nitrate: 1%
to 80%)
TN: 0.92 mg/l,
TKN: 1.34 mg/l,
NO2,3-N: 0.37
mg/l
Sorption and settling
(TKN), denitrification in
IWS (nitrate), and
plant uptake. Poor
removal efficiency can
result from media
containing high
organic matter.
3 feet Barrett et al. 2013; Clark and Pitt
2009; Geosyntec Consultants
and Wright Water Engineering
2012; Hunt et al. 2006; Hunt et
al. 2012; Kim et al. 2003; Li et al.
2010; Passeport et al. 2009;
Maniquiz, 2010; Winiarski et al.
2006
Infiltration Basin TC-11
June 2021 California Stormwater BMP Handbook 5-92
Development
www.casqa.org
Pollutant Typical
Removal
Median Effluent
Concentration1 Removal Processes Treatment
Depth References
Bacteria High Enterococcus:
235 MPN/ 100
mL, E.coli: 101
MPN/100 mL
Sedimentation,
filtration, sorption,
desiccation, predation,
and photolysis in
mulch layer and
media.
2 feet Geosyntec Consultants and
Wright Water Engineering 2012;
Hathaway et al. 2009; Hathaway
et al. 2011; Hunt and Lord 2006;
Hunt et al. 2008; Hunt et al.
2012; Jones and Hunt 2010
Trash High N/A Filtration 1.5 feet of
media
Barrett et al. 2013
1 Concentrations are based on bioretention performance data. Underlined effluent concentrations were (statistically) significantly lower than influent concentrations, as determined by statistical hypothesis testing on the available sampled data. Effluent concentrations displayed in italics were (statistically) significantly higher than influent concentrations.

Groundwater contamination concerns exists for infiltration basins (Lind and Karro, 1995; Datry et al., 2004; Pitt, 1999) but pollutant concentrations in the soil column have been shown to decrease rapidly with depth (within the first 6 to 18 inches) (Dechesne, M. et al., 2004; Dierkes and Geiger, 1999; Mikkelsen et al., 1997; Datry et al., 2004). However, pollutant concentrations can be of concern as deep as 10 feet, preferential flow pathways are suspected as the means of transport in some geologic settings (Winiarski et al. 2006). These observations warrant a 10 foot minimum between infiltration basin bottom and seasonal high water table.

Trash FCS
The Trash Amendments adopted by the State Water Board in April 2015 provide a performance standard for treatment of stormwater for trash in the form of the definition of FCS, which infiltration basin meets (see Section 5.6.1 for FCS details).

Suitability and Design
The use of infiltration basins may be limited by a number of factors, including type of native soils, climate, and location of groundwater table. Site characteristics, such as excessive slope of the drainage area, fine-grained soil types, and proximate location of the water table and bedrock, can also preclude the use of infiltration basins. The constraints of each site dictate the appropriate siting and footprint. Fundamental infiltration basin design components are as follows:
 Infiltration rate assessed on-site by a licensed geotechnical engineer or soil scientist.  Unsuitable if known soil contamination is present, or if upstream drainage area uses or store chemicals or hazardous materials that could drain to the basin.  10 feet of separation between bottom of the basin and seasonal high water table.

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 Drainage area that has been fully stabilized, plus use of a pretreatment BMP (e.g. grassed swales, gravity separator) at the entry point to ensure longevity.  10-ft setback from foundations, 100-ft from septic fields and water supply wells, and 50-ft from steep slopes.

Basin design is highly dependent on the constraints of the considered site. Costs will vary in accordance with the design. Table 2 details a number of core construction components and corresponding design considerations.

Table 2. Cost of design components and associated considerations Component Cost Design Consideration
Excavation Requires infiltration rate > 0.5 in/hr. When excavating ensure that subgrade compaction is minimized. Design
for 6 to 18 inches average ponding depth. Basin should
contain entire upstream WQV. After final grading, till the infiltration surface deeply
Without underdrains $2.75–$5.00/ft2
With underdrains $3.90–$6.15/ft2
Soil Media 1.5–4 feet (deeper for better pollutant removal, hydrologic benefits, and rooting depths) at minimum 5
in/hr infiltration. Total phosphorus < 15 ppm, pH 6–8,
CEC > 5 meq/100 g soil. Organic Matter Content < 5%
by weight. 65% sand, 20% sandy loam, and 15%
compost (from vegetation-based feedstock) by volume.

Recommended mix $2.90–$4.30/ft2
With engineered media $3.60–$5.40/ft2
Soil Media Barrier
When incorporating an underdrain, separate media from
native soil with a geotextile layer, 2 to 4 inches of
washed sand (ASTM C-33), followed by 2 inches of
choking stone (ASTM No. 8) over a 1.5 ft envelope of
ASTM No. 57 stone.

Geotextile $0.45/ft2
Washed sand (2-inch layer) $0.20/ft2
No. 8 aggregate (min 2 inches thick) $0.28/ft2
No. 57 stone (1.5 + feet) $2.49/ft2
Hydraulic Restriction Layer
May use hydraulic restriction layer on vertical surfaces to restrict lateral flows to adjacent subgrades, foundations, or utilities.

Filter fabric $0.45/ft2
Clay $0.65/ft2
30-mil liner $0.35/ft2
Concrete barrier $12.00/ft2
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Subsurface Option (Figure 1)
Excavation, Installation, and Backfill
Concrete Unit

$9.20/ft2
$59.93/ft2
Constructing a subsurface facility includes excavating to depth, installing concrete unit, overdig, and backfill.

Concrete unit height assumed here: 11' 4". Requires
pretreatment BMP to capture trash and debris.

Landscape $0.20–$3.50/ft2
Armor surface with cobble or vegetation. If planted
(optional), install native, deep rooting, and drought
tolerant plants.

Ensure that adequate head is available to operate flow splitter structures (to allow the basin to be offline) without ponding in the splitter structure or creating backwater upstream of the splitter.

Basin invert area should be determined by the equation. Where:

A = Basin invert area (m2)
WQV = water quality volume (m3)
k = 0.5 times the lowest field-measured hydraulic
Conductivity (m/hr)
t = drawdown time (48 hr)
Design Variations
When traditional surface basins are
infeasible because of land
constraints, subsurface extended
detention basin are ideal (Figure 1).

Open space parks (e.g., baseball
fields, etc.) are an example of where
a subsurface infiltration basin is
ideal because the park’s purpose as
a recreational area is not
compromised. Additionally,
recreational areas typical lack large
structures, therefore the issue of
overhead weight over the subsurface
unit is not a concern.

kt
WQVA=
Figure 1. Subsurface design of an infiltration basin, mid-construction.

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Full Trash Capture Compliance
This section provides trash-specific information to assist with upgrading either an existing BMP or the design of a planned BMP to meet the FCS definition. In addition to developing and adopting the Trash Amendments, the State Water Board provides implementation information on its Trash Implementation web page:
https://www.waterboards.ca.gov/water_issues/programs/stormwater/trash_implementation.h tml.

The web page includes information on best management practices or Full Capture Systems, including lists of State-certified Multi-Benefit Trash Treatment Systems. So, when selecting BMPs for trash control, fact sheet users should refer to both this BMP fact sheet and the State Water Board’s Trash Implementation web page.

Design Modifications to Prevent Trash Migration, Sustain Capacity, and Prevent Reduced Functionality
The infiltration basin must be configured to allow trash to enter the system and for trash to remain in the basin until it can be collected and removed. To meet the requirement, inlets must be designed to pass the peak flow produced by the one-year, one-hour design storm or the same flows as the capacity of the inlet storm drain and solids that would be retained by a 5 mm screen or mesh, must remain in the system.

Inlets
There are a multitude of inlet configurations that will allow trash to enter and be captured in an infiltration basin. An open inlet with a forebay is recommended.

Pretreatment
Pretreatment is beneficial to
increase and consolidate trash
capture while managing
maintenance requirements. A
forebay with mortared cobble is one
example of incorporating
pretreatment in the inlet (Figure 2).

This configuration can slow flow
and allow trash and gross solids to
settle out while consolidating at the
edge of the infiltration basin to
make it easier for maintenance
crews to collect and remove.

Figure 2. Example of a forebay as pretreatment for an infiltration basin.

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Trash Containment
Once trash has been captured in an infiltration basin it must be contained so trash does not escape the infiltration basin.

Containment may be provided by
one or more of these features:
 an external design feature or up-
gradient structure designed to
bypass flows exceeding the
region-specific one-year, one-
hour storm event; or
 the BMP having sufficient
capacity to trap particles from
flows exceeding those generated
by the one-year, one-hour storm
event; or
 the BMP having sufficient
capacity to treat either the
design flows or volumes through media filtration or infiltration into native or amended soils; or
 use of a maximum 5 mm mesh screen on all outlets.

Maintenance
A considerable cost concern associated with infiltration practices is the maintenance burden and longevity. If improperly maintained, infiltration basins have a high failure rate. Thus, it may be necessary to replace the basin with a different technology after a relatively short period of time.

To mitigate failure, ensure particulate loading of the stormwater is minimal, or is reduced with an adjacent pretreatment (i.e. vegetated buffer strip). Reducing the particulate loading enables the soils infiltrative capacity to stay high and functional.

Clogged infiltration basins reduced water quality performance but can also enable standing water to become a nuisance due to mosquito breeding. If the basin takes more than 48 hours to drain, then the rock fill should be removed and all dimensions of the basin should be increased by 2 inches to provide a fresh surface for infiltration. To mitigate failure, ensure particulate loading of the stormwater is minimal, or is reduced with an adjacent pretreatment (Figure 2).

Reducing particulate loading enables the soil’s infiltrative capacity to remain high and functional. Table 3 provides maintenance activity details, frequency, and costs.

Table 3. Typical maintenance activities and associated costs and frequency Frequency Cost Activity
Routine Maintenance (required monthly to every 2 years) Remove excess sediment, trash, and debris across the surface, inlet, and outlet. Check for and
stabilize erosion. Pruning and mowing overgrown Routine (small) $7.62/ft2 Figure 3. Example of an outlet with 5 mm screen.

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Frequency Cost Activity
Routine (medium) $1.91/ft2 vegetation that interferes with access, or safety (if applicable).

Routine (large) $1.91/ft2
End of Life Replacement (service life of 20 years) Excavate to the depth of soil media. Test soil for excessive soil contamination of common
stormwater pollutants (e.g. metals, nutrients).

Continue to remove underlying soil if pollutants
exceed standard for contaminated soil. Replace
with clean soil.

Replacement (small) $10.52/ft2
Replacement (medium) $10.17/ft2
Replacement (large) $10.11/ft2
Note: Small System = 500 ft2; Medium System = 2000 ft2; Large System = 4000 ft2 Underlined statement indicates that the activity may be required more frequently than shown in the table to meet the State Water Board maintenance criteria for Multi-Benefit Treatment Systems to be qualified as Full Capture Systems.

Trash FCS
Maintenance to Prevent Trash Migration, Sustain Capacity, and Prevent Reduced Functionality
For Multi-Benefit Treatment Systems to be qualified as Full Capture Systems, the State Water Board requires regular maintenance to maintain adequate trash capture capacity and to ensure that trapped trash does not migrate offsite. Additionally, the State Water Board requires the BMP owner to establish a maintenance schedule based on site-specific factors, including the design trash capacity of the Infiltration Basin Multi-Benefit Trash Treatment System, storm frequency, and estimated or measured trash loading from the drainage area. To meet those criteria, it is likely that the frequency of trash and debris removal will have to be increased above the recommended monthly interval during the wet season to prevent trash from being blown from the BMP or being washed out of the infiltration basin in the subsequent rain events (see Table 3). Depending on the frequency and size of storms, and upstream pollutant characteristics, trash and debris removal can be as frequent as before and after every wet weather event. The optimum maintenance frequency is best determined by site observation over an average water year.

Trash maintenance not only plays a role in the functionality of the infiltration basin but also in the aesthetics and public perception of the infiltration basin (and of all BMPs). Part of maintaining positive perception among the public is the visibility of a well-maintained BMP.

This positive perception can self-perpetuate further support for integrated stormwater management practices and therefore further investment in regular maintenance.

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Schematic

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References and Sources of Additional Information
Brown, W., and T. Schueler. 1997. The Economics of Stormwater BMPs in the Mid-Atlantic Region. Prepared for the Chesapeake Research Consortium, Edgewater, MD, by the Center for Watershed Protection, Ellicott City, MD.

Clark, S.E., and R. Pitt. 2009. Storm-water filter media pollutant retention under aerobic versus anaerobic conditions. Journal of Environmental Engineering 135(5):367–371.

Caltrans, 2002, BMP Retrofit Pilot Program Proposed Final Report, Rpt. CTSW-RT-01-050, California Dept. of Transportation, Sacramento, CA.

Datry, T., F. Malard, J. Gibert. 2004. Dynamics of solutes and dissolved oxygen in shallow urban groundwater below a stormwater infiltration basin. Science of the Total Environment 329: 215– 229.

Davis, A.P. 2007. Field performance of bioretention: Water quality. Environmental Engineering Science 24(8):1048–1063.

Dechesne, M., S. Barraud, J. Bardin. 2004. Spatial distribution of pollution in an urban stormwater infiltration basin Journal of Contaminant Hydrology 72: 189– 205.

Dierkes, C., W. Geiger. 1999. Pollution retention capabilities of roadside soils Water Science & Technology 39: 201-208.

Dorman, T., M. Frey, J. Wright, B. Wardynski, J. Smith, B. Tucker, J. Riverson, A. Teague, and K. Bishop. 2013. San Antonio River Basin Low Impact Development Technical Design Guidance Manual, v1. San Antonio River Authority. San Antonio, TX.

Galli, J. 1992. Analysis of Urban BMP Performance and Longevity in Prince George's County, Maryland. Metropolitan Washington Council of Governments, Washington, DC.

Geosyntec Consultants and Wright Water Engineering. 2012. International Storm Water BMP Database Pollutant Category Summary Statistical Addendum: TSS, Bacteria, Nutrients, and Metals. 2012. International Storm Water BMP Database. http://www.bmpdatabase.org/

Hathaway, J.M., W.F. Hunt, and S.J. Jadlocki. 2009. Indicator bacteria removal in stormwater best management practices in Charlotte, North Carolina. Journal of Environmental Engineering 135(12):1275–1285.

Hathaway, J.M., W.F. Hunt, A.K. Graves, and J.D. Wright. 2011. Field evaluation of bioretention indicator bacteria sequestration in Wilmington, NC. Journal of Environmental Engineering 137(12):1103–1113.

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Hilding, K. 1996. Longevity of infiltration basins assessed in Puget Sound. Watershed Protection Techniques 1(3):124–125.

Hong, E., M. Seagren, and A.P. Davis. 2006. Sustainable oil and grease removal from synthetic stormwater runoff using bench-scale bioretention studies. Water Environment Research. 78(2):141-155.

Hsieh, C.H., and A.P. Davis. 2005. Evaluation and optimization of bioretention media for treatment of urban stormwater runoff. Journal of Environmental Engineering 131(11):1521– 1531.

Hunt, W.F., and W.G. Lord. 2006. Bioretention Performance, Design, Construction, and Maintenance. North Carolina Cooperative Extension, Raleigh, NC.

Hunt, W.F., A.R. Jarrett, J.T. Smith, and L.J. Sharkey. 2006. Evaluating bioretention hydrology and nutrient removal at three field sites in North Carolina. Journal of Irrigation and Drainage Engineering 132(6):600–608.

Hunt, W.F., A.P. Davis, and R.G. Traver. 2012. Meeting hydrologic and water quality goals through targeted bioretention design. Journal of Environmental Engineering 138(6):698–707.

Jones, M.P., and W.F. Hunt. 2010. Effect of stormwater wetlands and wet ponds on runoff temperature in trout sensitive waters. Journal of Irrigation and Drainage Engineering 136(9):656–661.

Kim, H., E.A. Seagren, and A.P. Davis. 2003. Engineered bioretention for removal of nitrate from stormwater runoff. Water Environment Research 75(4):355–367.

Li, M.-H., C.Y. Sung, M.H. Kim, and K.-H. Chu. 2010. Bioretention for Stormwater Quality Improvements in Texas: Pilot Experiments. Texas A&M University in cooperation with Texas Department of Transportation and the Federal Highway Administration.

Li, H., and A.P. Davis. 2008. Urban particle capture in bioretention media. I: Laboratory and field studies. Journal of Environmental Engineering 143(6):409–418.

Lind, B. B., Karro, E. 1995. “Stormwater infiltration and accumulation of heavy metals in roadside green areas in Göteborg, Sweden,” Ecological Engineering, 5, 533-539.

Maniquiz, M., S. Lee, L. Kim. 2010. Long-Term Monitoring Of Infiltration for Nonpoint Source Pollution Control. Water, Air, & Soil Pollution. 212(1):13-26 Maryland Department of the Environment (MDE). 2000. Maryland Stormwater Design Manual. http://www.mde.state.md.us/environment/wma/stormwatermanual . Accessed May
22, 2002.

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Mikkelsen, P., Häfliger, M., Ochs, M., Jacobsen, P., Tjell, J. 1997. Pollution of soil and groundwater from infiltration of highly contaminated stormwater-a case study. Water Science & Technology, 36, 325-330.

Nightingale, H.I., 1975, “Lead, Zinc, and Copper in Soils of Urban Storm-Runoff Retention Basins,” American Water Works Assoc. Journal. Vol. 67, p. 443-446.

Nightingale, H.I., 1987a, “Water Quality beneath Urban Runoff Water Management Basins,” Water Resources Bulletin, Vol. 23, p. 197-205.

Nightingale, H.I., 1987b, “Accumulation of As, Ni, Cu, and Pb in Retention and Recharge Basin Soils from Urban Runoff,” Water Resources Bulletin, Vol. 23, p. 663-672.

Nightingale, H.I., 1987c, “Organic Pollutants in Soils of Retention/Recharge Basins Receiving Urban Runoff Water,” Soil Science Vol. 148, pp. 39-45.

Nightingale, H.I., Harrison, D., and Salo, J.E., 1985, “An Evaluation Technique for Ground- water Quality Beneath Urban Runoff Retention and Percolation Basins,” Ground Water Monitoring Review, Vol. 5, No. 1, pp. 43-50.

Oberts, G. 1994. Performance of Stormwater Ponds and Wetlands in Winter. Watershed Protection Techniques 1(2): 64–68.

Passeport, E., W.F. Hunt, D.E. Line, R.A. Smith, and R.A. Brown. 2009. Field study of the ability of two grassed bioretention cells to reduce stormwater runoff pollution. Journal of Irrigation and Drainage Engineering 135(4):505–510. Ramsey, C.G. & H. R. Sleeper. 1988. Architectural Graphic Standards (Eighth Ed.), Somerset, NJ: John Wiley & Sons.

Pitt, R., Clark, S., Field, R. 1999. Groundwater contamination potential from stormwater infiltration practices. Urban Water, 1:217-236
Scholes, L. M. Revitt, J. Ellis. 2007. A systematic approach for the comparative assessment of stormwater pollutant removal potentials. Journal of Environmental Management, 88(2008):
467–478.

Schueler, T. 1987. Controlling Urban Runoff: A Practical Manual for Planning and Designing Urban BMPs. Metropolitan Washington Council of Governments, Washington, DC.

Schroeder, R.A., 1995, Potential For Chemical Transport Beneath a Storm-Runoff Recharge (Retention) Basin for an Industrial Catchment in Fresno, CA, USGS Water-Resource Investigations Report 93-4140.

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Southeastern Wisconsin Regional Planning Commission (SWRPC). 1991. Costs of Urban Nonpoint Source Water Pollution Control Measures. Southeastern Wisconsin Regional Planning Commission, Waukesha, WI.

Tetra Tech (Tetra Tech, Inc.). 2014. Low Impact Development Handbook Stormwater Management Strategies County of San Diego Department of Public Works by Tetra Tech, Inc., San Diego, CA.

U.S. EPA, 1983, Results of the Nationwide Urban Runoff Program: Volume 1 – Final Report, WH-554, Water Planning Division, Washington, DC.

Watershed Management Institute (WMI). 1997. Operation, Maintenance, and Management of Stormwater Management Systems. Prepared for U.S. Environmental Protection Agency Office of Water, Washington, DC.

Winer, R. 2000. National Pollutant Removal Database for Stormwater Treatment Practices (2 nd
edition). Ellicott City: Center for Watershed Protection.

Winiarski, T., J. Bedell, C. Delolme, Y. Perrodin. 2006. The impact of stormwater on a soil profile in an infiltration basin. Hydrogeology Journal 14: 1244–1251.

Information Resources
Center for Watershed Protection (CWP). 1997. Stormwater BMP Design Supplement for Cold Climates. Prepared for U.S. Environmental Protection Agency Office of Wetlands, Oceans and Watersheds. Washington, DC.

Ferguson, B.K., 1994. Stormwater Infiltration. CRC Press, Ann Arbor, MI.

Los Angeles and San Gabriel Rivers Watershed Council (LASGRWC). 2010. Water Augmentation Study, Research, Strategy, and implementation Report. http://lasgrwc2.org/dataandreference/Document.aspx?search=48 USEPA. 1993. Guidance to Specify Management Measures for Sources of Nonpoint Pollution in Coastal Waters. EPA-840-B-92-002. U.S. Environmental Protection Agency, Office of Water, Washington, DC.

Site Design & Landscape Planning SD-10
Description
Design Objectives
@ Maximize Infiltration
@ Provide Retention
@ Slow Runoff
@ Minimize Impervious Land
Coverage
Prohibit Dumping of Improper
Materials
Contain Pollutants
Collect and Convey
Each project site possesses unique topographic, hydrologic, and vegetative features, some of which are more suitable for development than others. Integrating and incorporating appropriate landscape planning methodologies into the project design is the most effective action that can be done to minimize surface and groundwater contamination from stormwater.

Approach
Landscape planning should couple consideration of land suitability for urban uses with consideration of community goals and projected growth. Project plan designs should conserve natural areas to the extent possible, maximize natural water storage and infiltration opportunities, and protect slopes and channels.

Suitable Applications
Appropriate applications include residential, commercial and industrial areas planned for development or redevelopment.

Design Considerations
Design requirements for site design and landscapes planning should conform to applicable standards and specifications of agencies with jurisdiction and be consistent with applicable General Plan and Local Area Plan policies.

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Designing New Installations
Begin the development of a plan for the landscape unit with attention to the following general principles:
■ Formulate the plan on the basis of clearly articulated community goals. Carefully identify conflicts and choices between retaining and protecting desired resources and community growth.
■ Map and assess land suitability for urban uses. Include the following landscape features in the assessment: wooded land, open unwooded land, steep slopes, erosion-prone soils, foundation suitability, soil suitability for waste disposal, aquifers, aquifer recharge areas, wetlands, floodplains, surface waters, agricultural lands, and various categories of urban land use. When appropriate, the assessment can highlight outstanding local or regional resources that the community determines should be protected (e.g., a scenic area, recreational area, threatened species habitat, farmland, fish run). Mapping and assessment should recognize not only these resources but also additional areas needed for their sustenance.

Project plan designs should conserve natural areas to the extent possible, maximize natural water storage and infiltration opportunities, and protect slopes and channels.

Conserve Natural Areas during Landscape Planning
If applicable, the following items are required and must be implemented in the site layout during the subdivision design and approval process, consistent with applicable General Plan and Local Area Plan policies:
■ Cluster development on least-sensitive portions of a site while leaving the remaining land in a natural undisturbed condition.
■ Limit clearing and grading of native vegetation at a site to the minimum amount needed to build lots, allow access, and provide fire protection.
■ Maximize trees and other vegetation at each site by planting additional vegetation, clustering tree areas, and promoting the use of native and/ or drought tolerant plants. ■ Promote natural vegetation by using parking lot islands and other landscaped areas. ■ Preserve riparian areas and wetlands.

Maximize Natural Water Storage and Infiltration Opportunities Within the Landscape Unit ■ Promote the conservation of forest cover. Building on land that is already deforested affects basin hydrology to a lesser extent than converting forested land. Loss of forest cover reduces interception storage, detention in the organic forest floor layer, and water losses by evapotranspiration, resulting in large peak runoff increases and either their negative effects or the expense of countering them with structural solutions. ■ Maintain natural storage reservoirs and drainage corridors, including depressions, areas of permeable soils, swales, and intermittent streams. Develop and implement policies and 2 of 4 California Stormwater BMP Handbook
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regulations to discourage the clearing, filling, and channelization of these features. Utilize them in drainage networks in preference to pipes, culverts, and engineered ditches. ■ Evaluating infiltration opportunities by referring to the stormwater management manual for the jurisdiction and pay particular attention to the selection criteria for avoiding groundwater contamination, poor soils, and hydrogeological conditions that cause these facilities to fail. If necessary, locate developments with large amounts of impervious surfaces or a potential to produce relatively contaminated runoff away from groundwater recharge areas.

Protection of Slopes and Channels during Landscape Design ■ Convey runoff safely from the tops of slopes.
■ Avoid disturbing steep or unstable slopes.
■ Avoid disturbing natural channels.
■ Stabilize disturbed slopes as quickly as possible.
■ Vegetate slopes with native or drought tolerant vegetation. ■ Control and treat flows in landscaping and/ or other controls prior to reaching existing natural drainage systems.
■ Stabilize temporary and permanent channel crossings as quickly as possible, and ensure that increases in run-off velocity and frequency caused by the project do not erode the channel. ■ Install energy dissipaters, such as riprap, at the outlets of new storm drains, culverts, conduits, or channels that enter unlined channels in accordance with applicable specifications to minimize erosion. Energy dissipaters shall be installed in such a way as to minimize impacts to receiving waters.
■ Line on-site conveyance channels where appropriate, to reduce erosion caused by increased flow velocity due to increases in tributary impervious area. The first choice for linings should be grass or some other vegetative surface, since these materials not only reduce runoff velocities, but also provide water quality benefits from filtration and infiltration. If velocities in the channel are high enough to erode grass or other vegetative linings, riprap, concrete, soil cement, or geo-grid stabilization are other alternatives. ■ Consider other design principles that are comparable and equally effective.

Redeveloping Existing Installations
Various jurisdictional stormwater management and mitigation plans (SUSMP, WQMP, etc.) define "redevelopment" in terms of amounts of additional impervious area, increases in gross floor area and/ or exterior construction, and land disturbing activities with structural or impervious surfaces. The definition of" redevelopment" must be consulted to determine whether or not the requirements for new development apply to areas intended for redevelopment. If the definition applies, the steps outlined under "designing new installations" above should be followed.

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Redevelopment may present significant opportunity to add features which had not previously been implemented. Examples include incorporation of depressions, areas of permeable soils, and swales in newly redeveloped areas. While some site constraints may exist due to the status of already existing infrastructure, opportunities should not be missed to maximize infiltration, slow runoff, reduce impervious areas, disconnect directly connected impervious areas.

Other Resources
A Manual for the Standard Urban Stormwater Mitigation Plan (SUSMP), Los Angeles County Department of Public Works, May 2002.

Stormwater Management Manual for Western Washington, Washington State Department of Ecology, August 2001.

Model Standard Urban Storm Water Mitigation Plan (SUSMP) for San Diego County, Port of San Diego, and Cities in San Diego County, February 14, 2002.

Model Water Quality Management Plan (WQMP) for County of Orange, Orange County Flood Control District, and the Incorporated Cities of Orange County, Draft February 2003.

Ventura Countywide Technical Guidance Manual for Stormwater Quality Control Measures, July 2002.
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Roof Runoff Controls
Rain Garden
Description
Various roof runoff controls are available to address stormwater SD-11
Design Objectives
0 Maximize Infiltration
0 Provide Retention
0 Slow Runoff
Minimize Impervious Land
Coverage
Prohibit Dumping of Improper
Materials
0 Contain Pollutants
Collect and Convey
that drains off rooftops. The objective is to reduce the total volume and rate of runoff from individual lots, and retain the pollutants on site that may be picked up from roofing materials and atmospheric deposition. Roof runoff controls consist of directing the roof runoff away from paved areas and mitigating flow to the storm drain system through one of several general approaches: cisterns or rain barrels; dry wells or infiltration trenches; pop-up emitters, and foundation planting. The first three approaches require the roof runoff to be contained in a gutter and downspout system. Foundation planting provides a vegetated strip under the drip line of the roof.

Approach
Design of individual lots for single-family homes as well as lots for higher density residential and commercial structures should consider site design provisions for containing and infiltrating roof runoff or directing roof runoff to vegetative swales or buffer areas. Retained water can be reused for watering gardens, lawns, and trees. Benefits to the environment include reduced demand for potable water used for irrigation, improved stormwater quality, increased groundwater recharge, decreased runoff volume and peak flows, and decreased flooding potential.

Suitable Applications
Appropriate applications include residential, commercial and industrial areas planned for development or redevelopment.

Design Considerations
Designing New Installations
Cisterns or Rain Barrels
One method of addressing roof runoff is to direct roof downspouts to cisterns or rain barrels. A cistern is an above ground storage vessel with either a manually operated valve or a permanently open outlet. Roof runoff is temporarily stored and then released for irrigation or infiltration between storms. The number of rain January 2003 California Stormwater BMP Handbook
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barrels needed is a function of the rooftop area. Some low impact developers recommend that every house have at least 2 rain barrels, with a minimum storage capacity of 1000 liters. Roof barrels serve several purposes including mitigating the first flush from the roof which has a high volume, amount of contaminants, and thermal load. Several types of rain barrels are commercially available. Consideration must be given to selecting rain barrels that are vector proof and childproof. In addition, some barrels are designed with a bypass valve that filters out grit and other contaminants and routes overflow to a soak-away pit or rain garden.

If the cistern has an operable valve, the valve can be closed to store stormwater for irrigation or infiltration between storms. This system requires continual monitoring by the resident or grounds crews, but provides greater flexibility in water storage and metering. If a cistern is provided with an operable valve and water is stored inside for long periods, the cistern must be covered to prevent mosquitoes from breeding.

A cistern system with a permanently open outlet can also provide for metering stormwater runoff. If the cistern outlet is significantly smaller than the size of the downspout inlet (say ¼ to ½ inch diameter), runoff will build up inside the cistern during storms, and will empty out slowly after peak intensities subside. This is a feasible way to mitigate the peak flow increases caused by rooftop impervious land coverage, especially for the frequent, small storms.

Dry wells and Infiltration Trenches
Roof downspouts can be directed to dry wells or infiltration trenches. A dry well is constructed by excavating a hole in the ground and filling it with an open graded aggregate, and allowing the water to fill the dry well and infiltrate after the storm event. An underground connection from the downspout conveys water into the dry well, allowing it to be stored in the voids. To minimize sedimentation from lateral soil movement, the sides and top of the stone storage matrix can be wrapped in a permeable filter fabric, though the bottom may remain open. A perforated observation pipe can be inserted vertically into the dry well to allow for inspection and maintenance.

In practice, dry wells receiving runoff from single roof downspouts have been successful over long periods because they contain very little sediment. They must be sized according to the amount of rooftop runoff received, but are typically 4 to 5 feet square, and 2 to 3 feet deep, with a minimum of 1-foot soil cover over the top (maximum depth of 10 feet).

To protect the foundation, dry wells must be set away from the building at least 10 feet. They must be installed in solids that accommodate infiltration. In poorly drained soils, dry wells have very limited feasibility.

Infiltration trenches function in a similar manner and would be particularly effective for larger roof areas. An infiltration trench is a long, narrow, rock-filled trench with no outlet that receives stormwater runoff. These are described under Treatment Controls.

Pop-up Drainage Emitter
Roof downspouts can be directed to an underground pipe that daylights some distance from the building foundation, releasing the roof runoff through a pop-up emitter. Similar to a pop-up irrigation head, the emitter only opens when there is flow from the roof. The emitter remains flush to the ground during dry periods, for ease of lawn or landscape maintenance. 2 of 3 California Stormwater BMP Handbook
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Roof Runoff Controls SD-11
Foundation Planting
Landscape planting can be provided around the base to allow increased opportunities for stormwater infiltration and protect the soil from erosion caused by concentrated sheet flow coming off the roof. Foundation plantings can reduce the physical impact of water on the soil and provide a subsurface matrix of roots that encourage infiltration . These plantings must be sturdy enough to tolerate the heavy runoff sheet flows, and periodic soil saturation.

Redeveloping Existing Installations
Various jurisdictional stormwater management and mitigation plans (SUSMP, WQMP, etc.) define "redevelopment" in terms of amounts of additional impervious area, increases in gross floor area and/ or exterior construction, and land disturbing activities with structural or impervious surfaces. The definition of" redevelopment" must be consulted to determine whether or not the requirements for new development apply to areas intended for redevelopment . If the definition applies, the steps outlined under "designing new installations" above should be followed.

Supplemental Information
Examples
■ City of Ottawa's Water Links Surface -Water Quality Protection Program ■ City of Toronto Downspout Disconnection Program
■ City of Boston, MA, Rain Barrel Demonstration Program Other Resources
Hager, Marty Catherine, Stormwater, "Low-Impact Development", January/February 2003 . www.stormh2o .com
Low Impact Urban Design Tools, Low Impact Development Design Center, Beltsville, MD. www.lid-stormwater.net
Start at the Source, Bay Area Stormwater Management Agencies Association, 1999 Edition January 2003 California Stormwater BMP Handbook
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Efficient Irrigation SD-12
Design Objectives
0 Maximize Infiltration
0 Provide Retention
0 Slow Runoff
Minimize Impervious Land
Coverage
Prohibit Dumping of Improper
Materials
Description
Contain Pollutants
Collect and Convey
Irrigation water provided to landscaped areas may result in excess irrigation water being conveyed into stormwater drainage systems.

Approach
Project plan designs for development and redevelopment should include application methods of irrigation water that minimize runoff of excess irrigation water into the stormwater conveyance system.

Suitable Applications
Appropriate applications include residential, commercial and industrial areas planned for development or redevelopment. (Detached residential single-family homes are typically excluded from this requirement.)
Design Considerations
Designing New Installations
The following methods to reduce excessive irrigation runoff should be considered, and incorporated and implemented where determined applicable and feasible by the Permittee:
■ Employ rain-triggered shutoff devices to prevent irrigation after precipitation. ■ Design irrigation systems to each landscape area's specific water requirements. ■ Include design featuring flow reducers or shutoff valves triggered by a pressure drop to control water loss in the event of broken sprinkler heads or lines.
■ Implement landscape plans consistent with County or City water conservation resolutions, which may include provision of water sensors, programmable irrigation times (for short cycles), etc.

January 2003 California Stormwater BMP Handbook
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SD-12 Efficient Irrigation
■ Design timing and application methods of irrigation water to minimize the runoff of excess irrigation water into the storm water drainage system.
■ Group plants with similar water requirements in order to reduce excess irrigation runoff and promote surface filtration. Choose plants with low irrigation requirements (for example, native or drought tolerant species). Consider design features such as:

Using mulches (such as wood chips or bar) in planter areas without ground cover to minimize sediment in runoff
Installing appropriate plant materials for the location, in accordance with amount of sunlight and climate, and use native plant materials where possible and/ or as recommended by the landscape architect
Leaving a vegetative barrier along the property boundary and interior watercourses, to act as a pollutant filter, where appropriate and feasible Choosing plants that minimize or eliminate the use of fertilizer or pesticides to sustain growth
■ Employ other comparable, equally effective methods to reduce irrigation water runoff.

Redeveloping Existing Installations
Various jurisdictional stormwater management and mitigation plans (SUSMP, WQMP, etc.) define "redevelopment" in terms of amounts of additional impervious area, increases in gross floor area and/ or exterior construction, and land disturbing activities with structural or impervious surfaces. The definition of" redevelopment" must be consulted to determine whether or not the requirements for new development apply to areas intended for redevelopment. If the definition applies, the steps outlined under "designing new installations" above should be followed.

Other Resources
A Manual for the Standard Urban Stormwater Mitigation Plan (SUSMP), Los Angeles County Department of Public Works, May 2002.

Model Standard Urban Storm Water Mitigation Plan (SUSMP) for San Diego County, Port of San Diego, and Cities in San Diego County, February 14, 2002.

Model Water Quality Management Plan (WQMP) for County of Orange, Orange County Flood Control District, and the Incorporated Cities of Orange County, Draft February 2003.

Ventura Countywide Technical Guidance Manual for Stormwater Quality Control Measures, July 2002.
2 of 2 California Stormwater BMP Handbook
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Storm Drain Signage
Description
SD-13
Design Objectives
Maximize Infiltration
Provide Retention
Slow Runoff
Minimize Impervious Land
Coverage
0 Prohibit Dumping of Improper
Materials
Contain Pollutants
Collect and Convey
Waste materials dumped into storm drain inlets can have severe impacts on receiving and ground waters. Posting notices regarding discharge prohibitions at storm drain inlets can prevent waste dumping. Storm drain signs and stencils are highly visible source controls that are typically placed directly adjacent to storm drain inlets.

Approach
The stencil or affixed sign contains a brief statement that prohibits dumping of improper materials into the urban runoff conveyance system. Storm drain messages have become a popular method of alerting the public about the effects of and the prohibitions against waste disposal.

Suitable Applications
Stencils and signs alert the public to the destination of pollutants discharged to the storm drain.

Signs are appropriate in residential, commercial, and industrial areas, as well as any other area where contributions or dumping to storm drains is likely.

Design Considerations
Storm drain message markers or placards are recommended at all storm drain inlets within the boundary of a development project. The marker should be placed in clear sight facing toward anyone approaching the inlet from either side. All storm drain inlet locations should be identified on the development site map.

Designing New Installations
The following methods should be considered for inclusion in the project design and show on project plans:
■ Provide stenciling or labeling of all storm drain inlets and catch basins, constructed or modified, within the project area with prohibitive language. Examples include "NO DUMPING January 2003 California Stormwater BMP Handbook
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SD-13 Storm Drain Signage
- DRAINS TO OCEAN" and/or other graphical icons to discourage illegal dumping. ■ Post signs with prohibitive language and/or graphical icons, which prohibit illegal dumping at public access points along channels and creeks within the project area.

Note - Some local agencies have approved specific signage and/or storm drain message placards for use. Consult local agency storm water staff to determine specific requirements for placard types and methods of application.

Redeveloping Existing Installations
Various jurisdictional stormwater management and mitigation plans (SUSMP, WQMP, etc.) define "redevelopment" in terms of amounts of additional impervious area, increases in gross floor area and/ or exterior construction, and land disturbing activities with structural or impervious surfaces. If the project meets the definition of "redevelopment", then the requirements stated under " designing new installations" above should be included in all project design plans.

Additional Information
Maintenance Considerations
■ Legibility of markers and signs should be maintained. If required by the agency with jurisdiction over the project, the owner/operator or homeowner's association should enter into a maintenance agreement with the agency or record a deed restriction upon the property title to maintain the legibility of placards or signs.

Placement
■ Signage on top of curbs tends to weather and fade.
■ Signage on face of curbs tends to be worn by contact with vehicle tires and sweeper brooms.

Supplemental Information
Examples
■ Most MS4 programs have storm drain signage programs. Some MS4 programs will provide stencils, or arrange for volunteers to stencil storm drains as part of their outreach program.

Other Resources
A Manual for the Standard Urban Stormwater Mitigation Plan (SUSMP), Los Angeles County Department of Public Works, May 2002.

Model Standard Urban Storm Water Mitigation Plan (SUSMP) for San Diego County, Port of San Diego, and Cities in San Diego County, February 14, 2002.

Model Water Quality Management Plan (WQMP) for County of Orange, Orange County Flood Control District, and the Incorporated Cities of Orange County, Draft February 2003.

Ventura Countywide Technical Guidance Manual for Stormwater Quality Control Measures, July 2002.
2 of 2 California Stormwater BMP Handbook
New Development and Redevelopment
www.cabmphandbooks.com
January 2003