Supporting Explanation: These mitigation measures will reduce impacts to a level of less than significant because they will ensure the replacementof similar riparian vegetation and the creation of waters of the U. S. to mitigate jurisdictional waters lost to the development of TM 31930. The applicant has obtained a U. S. Army Corps of Engineers Nationwide Permit for a Linear Transportation Project. The permit authorizes the placement of fill for linear transportation projects permanently affecting less than acre of waters of the U. S. ( for the whole project.) The applicant has also obtained a California Department of Fish and Game (" CDFG') 1600 Streambed Alteration Agreement for the 0. 077 acres of CDFG jurisdiction that would be permanently affected by implementation of the project. The expansion of the unnamed drainage downstream of the Century Hills Drive road crossing, and adjacent to the water quality basin, will create 0. 028 acres of waters of the U. S. The project will also be required to install native grasses ( riparian vegetation) in the mitigation site. To ensure the establishment of the native cover, a 3- yearmaintenance and monitoring plan will be required. The impactsto wetland habitats would therefore be reduced to a less than significant level. 5) Potentially Significant Impact: TM 31930 will result in potential adverse impacts to wildlife resources.
Finding: Implementation of the following mitigation measure will reduce potential impacts to wildlife resources to a less than significant level.
Mitigation Measure:
The payment of fees pursuant to Section 711.4 of the Fish and Game Code is required. (IS., p. 22.)
Implementing this mitigation measure is feasible and the Commission adoptsand incorporates this measure into the Project.
C. Geology and Soils
1) Potentially Significant Impacts: Grading on slopes with an average natural slope greater than 10 percent could result in a potentially significant impact. The Project area is characterized by slopes ranging between about 10 and 30%, with an average natural slope of about 26%. The Grading Ordinance regulates project grading.
Portions of the following lots, building pads, and Project access roads are located in areas defined as ( i) the Alessandro Arroyo, and ( ii) the 50' development setback from the Alessandro Arroyo, according to the map attached to the Grading Ordinance, labeled Exhibit " D" (" Exhibit ' D'"): lots 37, 38, 39, 40, 41, 43, 44, 45, 46, 47, 48, 49, 50, 51, 57, 58, 59, 60, 61, 62, 77, and 78; and, Crest Haven Drive, Century Hills Drive and Grass Valley Way, and the sewer line extension.
Finding: Implementation of the following Condition of Approval will reduce potential grading impacts to a less than significant level:
17 12- 590
Condition of Approval 17: The Commission makes the necessary findings in the applicant's favor to grant the following grading deviations. As justification, the applicant's written grading exception findings are referenced:
i) 37-41, 43-49, 57-62, 77, 78, Crest Haven and Century Hills Drives, the water quality basin, the sewer line extension, and the Alessandro Arroyo Dam Access Road, encroach within the limits of the Alessandro Arroyo and the 50- foot development setback of the Alessandro Arroyo as defined in the Grading Ordinance; and
ii) To permit slopes in excess of twenty-feet for portions of Crest Haven, and Century Hills Drives.
Supporting Explanation: Although the lots, building pads, streets and sewer, identified above encroach within the areas identified as Alessandro Arroyo and 50' development setback on Exhibit " D", the location of the 50' setback on many of the lots does not comply with the definition of Alessandro Arroyo contained in the Grading Ordinance ( land within the watercourse area, the adjacent slopes having an average natural slope of 30% or greater" Grading Ordinance § 17. 28.020( 14)(b.)) In addition, pursuant to the City's administrative review process, grading can occur within the limits of the 50' setback and within the tributary if the area to be graded is not sensitive.
Sensitivity, in this context, is defined as the absence of (i) riparian vegetation, (ii) habitat for rare or endangered species, (iii) significant rock outcroppings or ( iv) other unique topographic features. The findings for the grading exceptions referenced above are hereby incorporated by reference as if set forth in full herein. 2) Potentially Significant Impacts: Erosion, changes in topography or unstable soil conditions from excavation grading, or fill could create a significant impact.
Project construction pursuant to a Nationwide General Permit ( No. 14) issued by the U. S. Army Corps of Engineers will result in the placement of 0. 028 acres of fill into a streambed. To mitigate potential impacts due to erosion, the California Regional Water Quality Control Board has issued a Section 401 quality standards certification, which identified the following required mitigation measures:
On - site mitigation measures: ( i) the construction of one water quality basin, with a containment volume of 7, 900 cubic feet of water storage area, to remove pollutants from nuisance and " first- flush" discharges, (ii) immediately downstream of the water quality basin, the Project will enhance the existing drainageto create an additional 0. 084 acres of waters of the U.S., and (iii) comply with additional mitigation measures proposed in the Storm Water Pollution Prevention Plan prepared for the Project.
Section 401 Conditions of Approval:
i) The water quality basin shall be clearly marked with signage identifying the basin's purpose and management restrictions. 18 12- 591
ii) A conservation easement shall be placed upon the water quality basin for the purpose of assuringits continued function for the life of the project. The conservation easement shall be recorded with the Riverside County Recorder's Office prior to occupancy of any residence within the project area.
iii) All disturbed slopes shall be stabilized for the purpose of preventing discharges of sediment-laden runoff during and after the conclusion of construction activities at the project site.
iv) The applicant, Sanda Group, Ltd., the owner, or its successors and assignees, shall fully implement the monitoring plan component described in the Mitigation Plan. Sanda Group, Ltd., the owner, or its successors and assignees, shall submit an annual report, due on or before September30th, to the Regional Board for a period of five years. The annual report shall document the maintenance, monitoring and success of the proposed water quality mitigation. If these measures are not property implemented and maintained, corrective measures must be implemented per consultation with the RWQCB and the resource agencies.
v) The phrase "NO DUMPING- DRAINS TO CREEK," or similar wording, shall be permanently affixed to catch basins throughout the project area to discouragedumping of pollutants into the storm drain system.
vi) Educational literature shall be distributed to homeowners and tenants to encourage reduction of non-point source pollution.
Implementing this mitigation measure is feasible and the Commission adopts and incorporates this measure into the Project.
Supporting Explanation: The Hydrology Study prepared by Gabel, Cook and Becklund, determined the size of the water quality basin required for the Project.
Condition of Approval 12 requires the installation of a water quality bio swale) to pre- treat urban runoff before it enters the basin. A conservation easement will be recorded to ensure the continued use of the water quality basin for drainagepurposes, and the Home Owner's Association for TM 31930 will be required to maintain the bio swale in perpetuity (Conditions of Approval 12 and 13). The impacts related to erosion, changes in topography or unstable soil conditions would therefore be reduced to a less than significant level. ( IS, p. 8.)
3) Potentially Significant Impact: The development of the Project could require grading which would impact unique geologic or physical features resulting in a significant impact. The main branch of the Alessandro Arroyo, and Alessandro Arroyo tributaries located within the Project site, are defined in the Grading Ordinance, and the Arroyo is designated for protection in the General Plan.
Finding: Implementation of the following condition of approval will reduce potential impacts to unique geologic or physical features to a less than significant level. 19 12- 592
Conditions of Approval:
No. 1: An open space easement shall be recorded for all areas within the boundaries of the 100 year flood plain and the setback there from ( and) all areas designated as open space; and, for each lot, all areas not proposed for grading under this review, subject to the approval of the Planning and Legal Departments. The easement should clearly specify that these areas are intended for open space purposes only and that no grading, construction, or fencing is permitted. The open space areas within the open space easement are to be maintained by a non- profit conservation organization such as the Riverside Land Conservancy subjectto the approval of the Planning and Legal Departments. The property shall be transferred either in fee title or an easement established to facilitate maintenance/stewardship by such an organization.
No. 9: The proposed project affects waters of the United States and waters of the State, which fall under the jurisdiction of the United States Army Corps of Engineers ("USACE") and the California Department of Fish and Game (" CDFG"), respectively. As such, the following agencieshave jurisdiction over this project, as necessary: CDFG, ACOE, the U. S. Fish and Wildlife Service, and the Califomia Regional Water ( Quality) Control Board. These agencies' approval will be required prior to grading permit issuance and the applicant is responsible for compliance with all requirements and conditions of these agencies.
No. 16: The grading plan shall be revised, subject to Planning Department review and approval, to:
a. clearly indicate all pad and lot drainage, subject to review and approval by the Planning and Public Works
Departments. Cross lot drainage covenants, if necessary, shall be subject to Public Works and Legal Departments' review and approval.
b. Indicate that all riprap will be natural rock ( not blasted) and all visible drainage features will be color treated to blend in with the natural surroundings.
c. Indicate an interim erosion control program to be certified by the project engineer subject to Public Works Department review and approval.
d. Reflect City adopted contour grading policies. Prior to issuance of a building permit, the applicant's engineer shall subject a letter certifying the contouring of such required slopes in accordance with City adopted standards.
e. Indicate that grading operations will be restricted to 7: 00a.m. to 7: 00 p. m. weekdays, and 8: 00 a. m. to
5: 00 p. m. Saturdays. No construction noise is permitted on Sundays or federal holidays.
20 12- 593
f. Indicate the 100~year flood limits of the blueline stream to the satisfaction of the Public Works Department.
No. 29: Grading activity shall be in substantial compliance with the grading plan on file with this application.
Compliance with these Conditions of Approval is feasible and the Commission adopts and incorporatesthese measures into the Project.
Supporting Explanation: The Arroyo tributaries will be retained within the open space easement, except areas for which administrative exceptions have been approved, based on findings that the tributary areas did not contain sensitive resources, pursuant to the Grading Ordinance, at section 17. 28.020 ( 14)(a). Rock outcroppings located in the open space lots, and will be protected by the Conservation Easement.
Certain areas inside the lots but outside the building pads will also be designatedas open space. Grading, the construction of structures, and fencing, will be prohibited on the open space lots and in the areas covered by the conservation easement. Ownershipof the Open Space lots will be transferred to a non- profit organization and an endowment set aside to provide for their long-term maintenance and management. Should no non- profit organization agree to own and maintain the open space lots and conservation easement areas, a home owner's association for TM 31930 will be established to maintain the open space areas and Covenants, Conditions and Restrictions will be imposed to ensure the perpetual maintenance and management of the open space lots and easement areas.
IS, p. 10.) All potential impacts to unique geologic or physical features would therefore be reduced to a less than significant level. ( IS, p. 9.) D. Hazards
1) Potentially Significant Impact: The Project will expose people to risks from airport operations because the Project is located within the March Air Reserve Base influence area.
Finding: Implementation of the following mitigation measure will reduce potential risks from airport operationsto a level of less than significant.
Conditions o f Approval:
No. 35: Submit documentation of approval by the Riverside County Airport Land Use Commission ( ALUC) to the Planning Department. All Conditions imposed by the ALUC shall be met to its satisfaction prior to map recordation. In the event the ALUC finds this map to be inconsistent with the Airport Land Use Plan, the case shall be considered by the City Council at a public hearing concurrently with the ALUC appeal.
21 12- 594
a. On- and off- site fire protection facilities shall be provided to the specifications of the Fire Department.
b. The Building Division and Fire Department shall inspect and approve the property and structure for the intended use and all standards and regulations shall be met.
c. Residential fire sprinklers shall be installed per City ordinance No. 6019. d. A public water system shall be provided and maintained. e. Streets and fire apparatus access roads shall meet public street standards.
Appropriate provisions shall be made and approved by the City resolution or agreement to insure streets are maintained and repaired when necessary in the even a homeowner's association fails to do so.
Cul- de-sacs, where islands are provided, shall be a minimum of 106- feet in diameter, curb- to-curb, with a maximum fifty-foot diameter island.
Entry gates shall meet Fire Department requirements for access and be equippedwith key box ( Knox) devices.
Implementing these mitigation measures is feasible and the Commission adopts and incorporatesthese measures into the Project.
Supporting Explanation: These mitigation measures will reduce impacts related to providing fire services to a less than significant level because they will require the following improvements to be constructed to comply with the following standards: ( i) on and off- site fire facilities shall be provided to the satisfaction of the Fire Department, ii) all residences constructed for TM 31930 shall be inspectedby the Building and Safety Department and the Fire Department to confirm that all standards required for a residential use are complied with, ( iii) residential sprinklers shall be provided in each residence, (iv) a public water system shall be installed and maintained in compliance with all applicable City standards, (v) streets and fire department access roads shall comply with all City requirements, ( vi) a provision shall be recorded to provide for the maintenance and repair of all streets in TM 31930 should the homeowner's association fail to take action, (vii) Grass Valley Way, a cul- de-sac in TM 31930 shall be constructed to comply with the Fire Department's required standards to provide for adequateaccess in the event of an emergency, ( viii) the gated entries at Crest Haven Drive and Century Hills Drive shall be equipped with Knox entry systems to provide for access by the Fire Department in the event of an emergency. These measures will ensure that potential impacts to the Fire Department's ability to provide service to TM 31930 are mitigated to a level of less than significant.
25 12- 598
Condition of Approval 35: Submit documentation of approval by the Riverside County Airport Land Use Commission ( ALUC) to the Planning Department. All Conditions imposedby the ALUC shall be met to its satisfaction prior to map recordation. In the event the ALUC finds this map to be inconsistent with the Airport Land Use Plan, the case shall be considered by the City Council at a public hearing concurrently with the ALUC appeal.
Implementing this mitigation measure is feasible and the commission adopts and incorporates this measure into the Project.
Supporting Explanation: The implementation of the condition of approval will reduce potential impacts to a level of less than significant because it requires that the ALUC approve the Project prior to recordation of the tract map. Or, altematively, if the ALUC does not approve the project, it grants to the City Council the authority to resolve any inconsistencies between the Project and the Air Port Land Use Plan. ( IS., p. 17.) J. Water
1) Potentially Significant Impact: The development of the Project will result in changes to the absorption rates, drainage pattems, and the rate and amount of surface runoff because of the increase in impermeable surfaces. ( IS, p. 10.) The applicant has received a Clean Water Act Section 401 Water Quality Standards Technically Conditioned Certification for the Proposed TM 28728, to mitigate impactsfrom discharges of pollutants to an unnamed drainagetributary to the Alessandro Arroyo,a tributary to the Santa Ana River.
Finding: Implementation of the following conditions of approval and mitigationmeasures contained in the Clean Water Act Section 401 Certification, will reduce potential impacts to water quality to a less than significant level:
Condition of Approval 9: The approval of the California Regional Water Quality Control Board will be required prior to the issuance of a grading permitand the applicant is responsible for compliance with all requirements and conditions contained therein.
Condition of Approval 12: A water quality bio- swale will be installed immediately downstream of the road crossing. The bio- swale will be installed in an upland location to provide pretreatment of urban runoff prior to dischargeinto the drainagefeature. The HOA will provide long-term maintenance, consistingof installation of native grasses, and sediment removal as needed.
Condition of Approval 14: The applicant shall be required to obtain necessary approvals and permits prior to any grading from the California Department of Fish and Game; the Army Corps of Engineers; the U. S. Fish and Wildlife Service; and the California Regional Water Quality Control Board. 27 12- 600
i) The applicantshall construct one vegetatedwater quality basin, with a containment volume of 7, 900cubic feet, for the purPOSe of pollutant removal from nuisance and " first- flush" discharges from the project site as described in the Mitigation Plan.
ii) Immediately downstream of the water quality basin, the applicant shall enhance the existing drainage to create an additional
0. 084 acres of waters of the US as described in the Mitigation Plan. iii) The water quality basin shall be clearly marked with signage identifying the basin's purpose and management restrictions. iv) A conservation easement shall be placed upon the water quality basin for the purpose of assuring its continued function for the life of the project. The conservation easement shall be recorded with the Riverside County Recorder's Office prior to occupancy of any residence within the project area.
v) All disturbed slopes shall be stabilized for the purpose of preventing discharges of sediment-laden runoff during and after the conclusion of construction activities at the project site.
vi) The applicant, Sanda Group, Ltd., the owner, or its successors and assignees, shall fully implement the monitoring plan component described in the Mitigation Plan. Sanda Group, Ltd., the owner, or its successors and assignees, shall submit an annual report, due on or before September 30th, to the Regional Board for a period of five years. The annual report shall document the maintenance, monitoring and success of the proposed water quality mitigation.
If these measures are not property implemented and maintained, corrective measures must be implemented per consultation with the RWQCB and the resource agencies.
vii) The phrase "NO DUMPING- DRAiNS TO CREEK," or similar wording, shall be permanently affixed to catch basins throughout the project area to discouragedumping of pollutants into the storm drain system.
viii) Educational literature shall be distributed to homeowners and tenants to encourage reduction of non- point source pollution.
Implementing these conditions of approval and mitigation measures is feasible and the Commission adopts and incorporates these conditions and measures into the Project.
Supporting Explanation: The Conditions of Approval in Mitigation Measures referenced above will reduce impacts to a level of less than significant because implementation of the mitigation measure would reduce water quality impacts by providing for the 79, 000 cubic foot vegetated water quality basin immediately below a bio- swale. The bio- swale is intended to pre- treat urban runoff from TM 31930 prior to discharge into the drainage feature. Maintenance of the bio- swale and drainage and water quality basin will be assigned to the homeowner association. Construction of the vegetated water quality basin will contain water from on- site to remove pollutants from 28 12- 601
nuisance and first- flush discharges. Because the Project is over one acre, a State Water Resources Control Board's general permit for stormwater discharges associated with construction activity, Water Quality Order 99- 08DWQ, is required, as is the preparation of a storm water pollution prevention plan ("SWPPP") to control discharges from the Project site. Additional on- site mitigation measures will be proposed in the SWPPP to further control dischargesfrom TM 31930.
2) Potentially Significant Impact: TM 31930 will discharge into surface waters or otherwise result in the alteration of surface water quality.
Finding: Implementation of the following mitigation measures will reduce the potential impacts related to discharge into surface waters or other alteration of surface water quality.
Mitigation Measures
7. A water quality bio- swale will be installed immediately downstream of the road crossing [the Arroyo]. The Bio- swale will be installed in an upland location to provide pretreatment of urban runoff prior to discharge into the drainagefeature. The HOA will provide long term maintenance, consisting of installation of native grasses, and sediment removal, as needed.
9. ' The applicant shall be required to obtain necessary approvals and permits prior to any grading from the . . . California Regional Water [ Quality] Control Board.
1 l(c ). A grading plan shall be revised, subject to Planning Department review and approval, to: indicate an interim erosion control program to be certified by the project engineer subject to Public Works Department review and approval.
20. The Regional Water Quality Control Board requires the preparation and implementation of a Storm Water pollution prevention Plan SWPPP.)
Implementing these mitigation measures is feasible and the Commission adopts and incorporates these measures into the Project.
Supporting Explanation: The mitigation measures identified above will reduce impacts related to discharge into surface waters or other alteration of surface water quality to a level of less than significant. Prior to grading on the site, the applicant shall complete the bio- swale as required by the California Regional Water Quality Control Board requirements. The bio- swale will filter on- site runoff prior to its collection in the first flush" basin, thereby protecting water quality in the adjacent drainage area. An interim erosion control plan shall be incorporated into the grading plan to protect water quality during construction, and the preparation of a SWPPP will also be required, to 29 12- 602
The developmentwas intended to be part of a Planned Residential Development (PRD).
Staff contend that the PRD is still current; however, with the expiration of the associated tract map the conditions of the PRD permit expired, and hence the incomplete part of the PRD also expired. It has not been renewed. Furthermore, the definition ofa PRD
19. 04.403) states that it must be "developed as a whole in a single developmentoperation or a programmed series of development operations in accordance with comprehensive and detailed plans which include the circulation system, parking facilities, open space, building sites, floor plans and elevations, together with a program for provision, operation and maintenance of such areas, improvements, facilities and services provided for common use of the residents thereof." We note that there are no floor plans or elevations available, nor are there is there a " program for provision, operation and maintenance" of the open space area. Thus the basic requirements for a PRD are not satisfied for this tract map.
The old PRD has already utilized about 14.8 acres of the area under discussion. This acreage must be set aside as open space, so that the present proposal occupies about 49.0 acres ofbuildable land ( see our Ietter of 18 August 2004 for more details). Part of this acreage is not owned by the applicants. It is owned by the Flood Control District. The approval of the old tract map 28728 in 1998 included the Flood Control Land in the calculation total area ( and the prior 1994 calculation probably did so as well), and yet after at least 6 years the applicants have failed to justify that density calculation by purchasing the land. Since the applicants neither own the property, nor is the property in escrow, we believe that the approval of the planning commission to rezone the land from O zone to RC was premature. We do not know if the sale will occur, and if it does, we do not know what restrictions may be placed on the use of the land. It is therefore inappropriateto include this land in the proposedtract map.
Some of the reasons why a Neg. Dec. cannot be approved for this project are outlined in our previous letters, and we will add further detail later. However, a crucial factor that prohibits approving a Neg. Dec. is the omission of serious consideration of the constraints imposedby the Hawarden Hills Specific Plan ( HHSP). First, the Plan emphasizesthe lowering of housing density towards the Alessandro Arroyo. in this tract map, this does not occur at the eastern and western ends. Most noticeable, there are the two clusters of homes ( lots 43- 46 and 47-49) that encroach into the main Alessandro Arroyo and will be very detrimental to the natural open space of the Arroyo. Second, the HHSP requiredthe creation of a trail corridor from Tiburon Knoll to the Alessandro Arroyo. Note that the specification was not for a trail, but for a trail corridor occupying an anticipated 15 acres.
This corridor area is shown in the HHSP plan within the area of TM 31390. No trail corridor has been included in the design of the tract map; in fact there is not even a trail included in the tract map. Condition 22 of the tract map requiresthat the applicants provide "a trail across the subjectproperty for eventual connection to Tiburon Knoll"; however, this does not state that the trail must reach the Alessandro Arroyo, it does not state that it cannot be along a road, and it does not state the width of the trail. The approved tract map CANNOT incorporate an open space trail from the Alessandro Arroyo to the area north of lots 56 and 57 (as shown in the HHSP) utilising the defined open space. The options for such a trail that satisfy the requirements of the HHSP must be considered as part of an EIR.
GRESHAM SAVAGE NOLAN ~ gr TILDEN,
A PROFESSIONAL CORPORATION
Alicen CLark Wong
September28, 2004
owner to purchasethe flood control land, and the phasesof the tract map that were recorded did no~t include the flood control land. However, the flood control land is located in TM 31930, and the City has imposed the following two conditions regardingthe flood control land: Prior to map recordation "[ t] he applicant shall obl:ain final authorization from the Riverside County Flood Control District or the applicant shall have acquired such property" (Condition of Approval 4); and "[o] wnershipof property shall he undivided prior to this map recording" (Condition of Approval 50). Based on these conditions, the applicant will be required to purchasethe flood control land before recording TM 319130.
5. Authorization for the Rezone of the Flood Control Land from O to RC: The applicant has submitted to the City several letters from The Riverside County Flood Control District regarding the purchase o13' the 17acres and including it in the Project (see Attachment"B"). The earliest, dated March 28, 1994, consists of a memorandum of understanding identifying the District's willingness to sell the flood control property to the applicant for fair market value upon the happening of certain conditions. A second letter, dated April 10, 2003, from Bill Gabel, tlne applicant's engineer, reflects continuing negotiations regarding several conditions to the acquisition. A third letter from the applicant, dated June 27, 2003, documents a meeting between the applicant and the District which occurred in early 2003, during which the District again agreed to sell the property. The most recent letter, dated April 6, 2004, reflects a telephone conversation which occurred among Stephen C. Thomas, Chief of Operations of the Flood Control District, City Councilman Frank Schiavone, and the applicant.
The letter reflects the on- goingnature of the negotiations regarding the purchase of the property, memorializes the commitment to sell contained in the 1994 letter, and asks the District to send written correspondenceto the City '!_f it does not want the property included in the Project.
Because the City has received no written correspondencerescinding the District's 1994 letter, the flood control property continues to be included in the Project.
6. Elevations Missing from PRD Application Package: The aesthetic concerns raised by the commenter will be addressed after the approval of the entitlements, during the design review process. In this case, footprints for the homes caimot be proposed until the Project is approved, because the shape and size of the footprints depends on the approval of the Variances and Grading Exceptions. Therefore, the creation of elevations and landscapeplans prior to Project approval would be premature. The City has imposed a Condition of Approval which requires that "[ a] ll other applicable standards of the underlying RC- Residential Conservation Zone shall be met" ( Condition of Approval 36). Compliance with the Design Review process is required for all developments in the RC Zone. The RC Zone specifies that no building permit shall be issued for any building or structure in the RC zone until slope planting and irrigation plans and the drawings required by Chapter 19.62 for design review have been submitted to and approved by the Design Review Board or City Council in accordance with the provisions of Chapter 19. 62.
GRESHAM SAVAGE NOLAN & TILDEN,
A PROFESSIONAL CORPORATION
Alicen Clark Wong
September28, 2004
Page4
The Design Review Board is required to consider the following items of particular concern in the RC zone:
A. The encouragement of unique site design to ensure optimum treatment of natural hillside: and arroyo features and avoid inharmonious, incongruent, conspicuous and , obtrusive development;
B. The reduction of the scarring effects of grading and the protection of slopes subject to erosion, determination or slippage, and fire by the use of appropriate slopeplanting, irrigation, and maintenance; and C. The encouragement of structures which will relate spatially and architecturally with the enviromnent and complement the natural land forms.
Conditions may be applied when the proposed development does not comply with applicable standards and shall be such as to bring such development into conformity or the plans and drawings may be disapproved and the Board shall specify the standard or standards that are not met. City of Riverside Municipal Code, RC Zone § 19. 09.090, emphasis addedI.
The aesthetic concerns raised in the comment will be addressed during the DesignReview process by compliance with the standards in the City Code.
7. Density Penalty: The PRD section (§ 19. 65B) provides for a density bonus of up to 25% if the project complies with certain specified criteria. The information below supports the City's grant of a density bonus for the Project.
Criteria Permitting a 25% Density Bontus:
The property is well located in close proximity to schools, shopping, and publicand semipublic facilities.
A. Schools:
Public Schools Serving the Proiect Area: Taft Elementary School ( K~6), Victoria Elementary School ( K- 6), Washington Elementary School ( K- 6), Castleview Elementary School K- 6); Gage Middle School ( 7- 8) and Poly High School ( 9- 12), to the north.
From this point forward, all unreferenced citations are to the City of Riverside Municipal Code.
GRESHAM SAVAGE NOLAN & TILDEN,
A PROFESSIONAL CORPORATION
Alicen Clark Wong
September 28, 2004
Page5
Private Schools Within a 10- mile Radius: Riverside Christian Day School ( K- 6); Woodcrest Christian Middle School (, 6- 8); Woodcrest Christian High School ( 9- 12); Hawarden Hills Academy (1- 8); Emanuel Lutheran School ( K- 6); Riverside Christian School ( K- 12); and Montessori School on Indiana ( preschool).
B. Shopping:
Groceries: Within a 5- minute drive to the southeast of the Project, on the southwest comer of Alessandro and Trautwein, is the Mission Grove Plaza shopping center, which contains Ralphs, K- Mart, Steinmart ( a clothing, store), a Cinema Star theater, and a variety of fast food restaurants.
Groceries and Restaurants: Within a 10- minute drive to the northwest of the Project is the Riverside Plaza shopping center, which contains grocery and general merchandise stores including, but not limited to: Trader Joes, Vons, Sav-On Drags, and See's Candy. Sit- down restaurants and fast food eateries, include; Islands, Fazoli's, Spoons, and Wendy's.
Regional Mall: Within a 15- minute drive from the project is the Tyler Mall, located southwest of the project, off the 91 Freeway at the Tyler exit.
Freeway Access: Access to the 91 Freeway is about 10- minutesaway, off Arlington Avenue, to the northwest of the project. Access to the 215 freeway is about 15- minutesaway, off Alessandro Boulevard, to the east of the project.
C. Public Facilities:
Taft Park, Castleview Park, and Sycamore Canyon Wilderness Park are located within a I O- minutedrive from the project, in the: surrounding neighborhood.
2. The property enjoys excellent access from the following adjoining public streets:
Alessandro Boulevard, the main circulation street, from Trafalgar to the west, and Century to the east.
The design of the project exhibits superior utilization of the site as evidenced bythe following criteria:
a) Varied placement of buildings demonstrating sensitivity to the natural topographic fealures of the site. TM 31930 clusters the lots next to the streets to minimize grading, and combines all acreage outside the lots into open space. Clustering maximizes the size of the open space lots by packing the building pads and the streets close together. This preserves blocks of open space outside the lots and building pads for dedication as open space.
GRESHAM SAVAGE NOLAN ~ TILDEN,
A PROFESSIONAL CORPORATION
Alicen Clark Wong
September28, 2004
iii) Effect of Drought on Proposed Location of Water Quality Basin and SewagePumping Station: The commenter suggests that the drought, fire several years ago, and weed clearance could have temporarily modified the area at the proposed intersection of Century Hills Drive and Grass Valley Way. This comment is speculative, and without supporting evidence. Because there is no evidence to support this comment, it does not amount to substantial evidence.
iv) Objection Regarding the Maintenance of the Arroyo Open SpaceArea by the Home Owner's Association: The commenter objects that if the Home Owner Association maintains the open space, because of its lack of expertise, mismanagementwould result that would constitute a potentially significant impact. This is conjecture and has no basis in fact. It is equally plausible that the Home Owner Association would contract with a non- profit organization to satisfy their maintenance obligations.
v) Change in Drainage Patterns: The commenter identifies the areas subjectto fill from road construction as " tributary arroyos" and suggests that the development of Century Hills Drive will change the drainage patterns and that the changeshave not been studied.
The applicant prepared a Hydrology Study and Storm Water Mitigation Plan, dated May 15, 2003 ( the "Study"), which analyzed the impacts of the Project on drainage. That study identified two low points where Century Hills Drive would interfere with the natural flow of water in the tributary area. TM 32270 is proposing culverts in both low points to preserve the existing water flows according to pre- Projectconditions. See Best Management Practices, identified in the Study at page 1, at Attachment " E".
The Study was also used to , determine the type and size of the water quality basin necessary to mitigate storm water runoff ( Id. at page 2). Other improvements related to drainageinclude a vegetated water quality basin southwest of the intersection of Century Hills Drive and Grass Valley Way, to comply with the Clean Water Act; and a water quality bio- swale, immediately downstream of the Century Hills Drive road crossing (TM 31930 Condition of Approval I5). The bio- swale will pre- treat urban runoff prior to its discharge into the drainage feature, and will be maintained by the Home Owner Association. vi) Trails: The commenter requests that the trail included in the Hawarden Hills Specific Plan be required as part of TM 31930. However, because the Hawarden Hills Specific Plan is not applicable to the subject Property, the trail to Tiburon Knolls, identified in that document, is not required in connection with the approval of TM 31930. However, as discussed above, a trail in the Alessandro Arroyo is proposed and will be required by a condition of approval.
vii) Potential Impact of Sewer Line: The commenter is concerned regardingthe Home Owner Association's ability to manage the sewer line extension on a long-term basis.
The installation of the sewer line was analyzed in the Biological Assessment dated December 15,
GRESHAM SAVAGE NOLAN & TILDEN,
A PROFESSIONAL CORPORATION
Alicen Clark Wong
September 28, 2004
2003. No potential significant impacts to biological resources were identified. The commenter raises a concern regarding the futtu:e functioning of that line. This question is based on speculation and does not constitute substantial evidence of a potential environmental impact. All City and State legal requirements would have to be met with regard to the maintenance of the bio- swale. The ability of the Home Owner Association to maintain the bio- swale also is a matter of speculation which does not amount to substantial evidence.
Letter from Len Nunney on Behalf of Friends of Riverside's Hills, dated March 25, 2004 The issues that are discussed in this objection letter reflect many of the same issues contained in the letter dated August 18, 2004, and therefore, many responses to this letter are included in the information above.
1. The hearing on TM 31930 should be continued until the developerhas some rightto purchase the O zoned land from the Flood Control District. This issue is discussed in number 4, above.
2. The rezoning of 7 acres of O- zoned land to RC should not be permitted. The commenter does not provide any support for this assertion. We have been unable to identify a provision in the City Zoning Code which prohibits a zone change to the RC zone.
3. There are excessive grading exceptions for this tract. See response numbers 7 and 8, above.
4. Century Hills Drive is unacceptable because it is proposed within the arroyo area.
See response number 17, above.
5. TM 31930 does not provide for public access trails, such as the Alessandro Arroyo trial identified in the Hawarden Hills Specific Plan, and in the General Plan. See the responses to numbers 3, and 20 (ii) and (iv) above.
required.
General comment reiterating comments 1-5 above. Comment noted. No answer Letter from Eva K. Rose, Charley College Honors Program, received by the City on April 13,2004 This letter suggests that the only reason for the grading in the Arroyo is to create larger building pads. This comment does not take into account the small and irregular building padsthat would result without the proposed Grading Exceptions. With Grading Exceptions, the proposed building pads will be consiistent with the requirements of the Grading Ordinance, 27, 000 square foot maximum for lots with an ANS between 10% and 15%, 21, 000 square foot
GRESHAM SAVAGE NOLAN & TILDEN,
A PROFESSIONAL CORPORATION
Alicen Clark Wong
September28, 2004
for lots with an ANS between 15% and 30%, and 18, 000 square foot for lots with an ANS between 30% and 40%). These are not large building pads, they are adequateto construct one- story houses ( required in the RC zone) with a garage ( required by City Ordinance).
The commenter states "[ als the land cannot be developed and the purpose of the grading is merely to satisfy the acreage needs of the developer, I find this misappropriationof this land a most serious violation of both the wildlife and all who are concerned with proper land management." This comment apparently relates to the rezoning of the property zoned O to RC.
This issue is discussed in response number 2 to Len Nunney's March 25th letter, above.
Letter from Mark Juhasz Regarding P03- 1358/P04- 0015
This letter was included in the: packet in error because the case numbers do not match the Project.
Very truly yours,
Alicen Clark Wong, of
GRESHAM SAVAGE
NOLAN & TILDEN,
A Professional Corporation
Enclosures
cc: Jim Guthrie
Jennifer Guenther
N:\ G397-000 \ LTR \ Objection Ltr Response.doc
9 of 10
lb) Land use and planning. Conflict with applicable environmental plans or policies.
The response to this question is based on a previous approval for TM 28728; however, this does not guarantee the approval now. In any event, there is a significant change. There is a wetland/ stream area at the intersection of Century Hills Drive and Grass Valley Way. This wetland will now be severely impactedby the settling ponds and sewage pumping station sited by the wetland. Furthermore the potential impacts of the sewage pumping station and sewage line on the Alessandro Arroyo and surrounding area have not been considered. This changehas a potentially significant impact, and is not mentioned.
This wetland area was identified by R. B. Riggins in their Biological Assessment of 2001, but the March 2003 jurisdictional delineation by Michael Brandman Associates ( MBA) considered the area to be part ora jurisdictional water, but not a wetland; however, MBA failed to provide any data associated with their determination. Solid, substantially more jurisdictional waters were identified in the 2001 study then were seen in a 2003 study. Given the importance of wetlands and jurisdictional waters, this difference of opinion should be resolved by an independent survey as part of an EIR. The fact that a 5-yr draught, the fire a few years ago, and weed clearance can temporarily modify the signatures used for wetland delineation was ignored. The delineation needs to be done again and after a good storm.
3e) Geology and Soils. Grading on Natural Slopes over 10%.
Contrary to the view of Staff, we consider that the excessive grading on steep slopesproposed in the project is not justified by the Findings and has a potentially significant impact. Most of the statements in this section are taken from the Findings made by Staf£ We disagreewith the validity of many of these statements and have commented upon them earlier in section 5 Findings).
30 Geology and Soils. Unique geologic or physical features.'? The Alessandro Arroyo and its major tributaries are recognized as . a significant landform. The grading ordinance clearlydelineates the arroyo system using objective criteria. The Staff recognize that this project will impact some major portions of the arroyo. In fact, the excessive grading impacts both the main arroyo and some of its major branches. In addition, where Century Hills Drive crosses the open space, it is within the area of the main arroyo and will result in extensive filling of these majorbranches. Such actions will have a potentially significant impact on the unique landform of the area.
Staffnote the possibility that the long term maintenance and management of the arroyo open space may be left to the Home Owners Association ( HOA). A HOA has no expertise in managing such an important resource, and approval of the CC& Rs by the Planning Staff and the. t, ~ City Attomey's Office does nothing: to improve the situation, since they have no expertise in this~" ~area either. Allowing the possibility of long-term management by the HOA has a potentially significant impact.
4a) Water. Change in absorption rates, drainage patterns... ~ taff ~1~!o comment on the changes to the drainage patterns resulting from th }~'~ br the roads. In particular, the junsdlctmndl waters, and ~~ '~ a~ r~a~ tl~[tion of Grass Valley Way and Century Hills Drive, will be impacted by both the roads, the sewage pumping i ' "' "stat on, and by the setthng b~ o-swale . This is a source of potentially significant impact.
10 of 10
4b) Water. Discharge into surface waters... The impact of the settling pond, and the other sources of water that wil.1 be dischargedinto the Alessandro Arroyo as a result of the surface waters from streets etc running down to the open space areas. This could have a potentially significant impact. The cumulative impact of increased impermeable surfaces, changesin percolation and runoff patterns, and how this affects this important watershed need to be addressed in a thoughtful manor.
15b) Recreation. Affecting existing recreational opportunities. Staff correctly note that the Harwarden Hills Specific Plan ( HHSP), a part of the City General Plan, identifies a trail corridor from the Alessandro Arroyo to the Harwarden Hills Vista Point that passes along the whole western edge of the tract map. Staff suggest that this requirement will be satisfied by a trails easement identified at the time of project development. This is unlikely to be successful, since there is currently no way that a continuous open space trail can be placed within the tract map along the western edgeof the property. It would have to pass directly through lots 54- 56.
Moreover, as noted earlier, the HHSP stated that about 15 acres should be set aside for the trail,and it is clear that no such provision has been made within the current project. This is a potentially significant impact.
Another potentially significant impact concerns the Alessandro Arroyo trail. This is part of the City General Plan, but its location has not been considered. Serious consideration of the optionsfor the location of this trail must be part of the evaluation of this tract map. 16a) Mandatory findings of significance. Does the project have the potential to degrade the quality of the environment... Staffresponse is no. However, they fail to recognize the importance of the lon- term management of the environment ( see 3i) in maintaining the quality of the environment. Additionally, the problems of getting the settlement " bio- swale" to work effectively are not considered, and the potential dangers from the sewage line running across the open space area above the Alessandro Arroyo are not considered. In addition, the project does have the potential to reduce the number of rare animals ( two species were mentioned earlier as being seen on site during our walk through, although neither was seen by Michael Brandman Associates during their survey).
In summary, this project is likely to have a number of potentially significant impacts, and for this reason the negative declaration should be denied and an EIR requested. The excessive variances and grading exceptions are indicative of the problems associated with this project, and should be denied.
The PRD criteria for a density bonus arc not satisfied and a density reduction is warranted, reducingthe number of lots below 24. Finally, tl~e requirements of the Harwarden Hills Specific Plan are largely ignored. Specifically, the Plan requires a substantial area to be dedicated to a trail from Tiburon Knoll to the Alessandro Arroye,, and a reduction in housing density close to the arroyo.
Thank you for your attention.
Communicated for Friends of Riverside's Hills by Len Nunney4477 Picacho Dr., Riverside, CA 92507 email: watkinshill~juno.com
phone: (909) 781-7346
Chaffcy College Honors Program
To:
Honorable Chair and Members of the City of Riverside Planning Commissac F~ oEn:
Scott arid ' Eva Rose
6381 Century Hill Drive
Riverside, CA 92506
RE: P03- 1451/P03- 1548/P04- 0260
PLANNIt~G DEFA~U MENT ·
As a concerned and soon to be greatly' affected homeowner'in the Hidden Canyon Estates, ] would like to both articulate my apprehension-and reaffirm the stated posifipn expressedby .my fellow homeowners and our representative'of Friends of Riverside' s Hills, Leonard tqonney.
The h~ an of my apprehensionlies in a couple of the Central components of the afo/- ementioned developmem proposals..I will briefly highlight these concerns as follows:
1. The proposedgrading of th~ ~M- r0yofor the sheet purpose of having "larger building pads" seems to me a most grave masmanagement of such a' vital habitat for its dozens of species. As this land cannot be developed and Uae pgrpose of the grading i* merely to satisfy the acr~ge needs of the developer, 1 find this misappropriation of this ] and a most serious violation of both the wildlifeand all who are concerned with proper land management.
2. In my understanding of the proposalsthusfar~ there have been no formal provisions to develop publi~ access trails according to the City's General Plan. In facl, the lack of such a provision seems to be indic ative of an ethos that runs.quite counter to that of the original intentions of the City' Planners for this area and indeed the motivations fOr migratingto this area of most if not all of its current inhabitants. What wa,, once the promiseand most appealingclement of living in this area ( a close and non- obtrusiveco- existence with the surrounding natural habitat) is now the very thing under serious attack.
In light of these and other concerns a Js my ~trong suggestion, in solidariiywith Uae community in which 1 find m:,'~.e, lf, to delay ;~1! such ~le'-' e!cr- mr-nt until the. concernsand desires of all affected partiesare both acknowledged and respected. Thank you for your time and consideration.
Sincerely
Eva.K. Rose
Dilrectur, Cbaffey Col!ege Honors Program
Professor, Dept. of Communicati6n ,., md{ es
ATTACHMENT B
RIVERSIDE COUNTY FLOOD CONTROL DISTRICT LETTERS
Dated March 28, 1994, from the District to William Gabel Dated April 10, 2003, from William Gabel to the District Dated June 27, 2003, from Jim Guthrie to the District
Dated April 6, 2004, from Jim Guthrie to the District
10 Apdl 2003
Riverside County Flood Control & Water Conservation Distdct 1995 Market Street
Riverside, CA 92 501
Attn: Coen Cowenburg
Re: Tract 28728
City of Riverside
Alessandro Dam
Dear Coen,
Reference is made to our previous meeting concerning the above referenced project. Attending that meeting was my client, Jim Guthrie, mysalf, you and Dusty Williams. We discussed my client's desire to acquire a portion of a 17.38 acre parcel of land ovwed by the Distdct and lying just northerly of yourAlessandro Dam site. The majodty of this parcel lies at an elevation above the top elevation of the dam,thus being outside all flooding limits. A small portion of the parcel is occupied by a portion of the dam's spillway and adjacent slopes. This parcel was shown by RS 67/ 91-92 and its APN is 243- 180-003. The portion of the parcel my client desires to acquire is shown on the enclosed final map for Tract 28728 andcontains 15. 98 acres. This po~on of thE; parcel will be incorporated within the tract's boundaries and, as you can see by the tract map, will largely be dedicated and reserved as an open space easement. This open space will be maintained by the project homeowner's association.
In the meeting, you indicated that the District could support the acquisition of this property by my clientand that you would require the construction of an access road fram the project's private street system tothe spillway area of the dam. In addition, you would require that the project owner dedicate ingress and egress easement dghts to the Distdct over this access road and private street system.
I have also enclosed a copy of the project grading plans for your review showingthe private road system,access road and the dam's spillway locations. We would propose the dedication of the requiredeasements by separate deeds to record concurrent with the map's recordation.
Please review the enclosed plans and then call me so we might meet to discuss the next step in this process. You can reach me at 909- 288-¢602. Thank you for your consideration.
Respectfully,
Gabel, Cook & Becklund, Inc.
William D. Gabel
Civil Engineer
Enclosures
N:\ 0998~DOCu ments~RCFC D letter.doc
Riverside County Flood Control
1995 Market Street
Riverside, Ca 92501
June 27, 2003
Auention: Co~n Couwenberg, P.E.
Re: Purchase of Allessandro Arroyo Property
Dear Co~:
Just a note to let you know that we are pursuingvigorouslythe purchaseof the Prenda reservoir property. As you know, the Agency agreedto sell the property to Dr. Hong Per letter received in 1996. Based on that information, a map was pursuedand a tentative was r~ ceived (T. M.28728). In th~; beginning of 2003, a meeting was held with yourself and the now new director of thc Flood Control that restated the sale of the property would be made to Dr. Hong to satisfy tha conditions of/ he Map.
At the 2003 meeting, it was agreed/hat an appraisalwould be needed that would set the price, less any benefits that we would provideto the flood control regardingaccess for future maintenance.
As you know, we have waited sotnetime for an answer from Flood Control about the actual ability to deliver the prope~x'y. In the mean time our map will expireon July 21, 2003. We will be requireto file and get a new number and have a new public hearing.
This process will take approximately 90 days. We would hope that we could pursue and fina!ize a purchase within that time hame. We realize that the Flood Control process is controlled by the Board of Supervisors and that after a deal is struck regarding terms and conditions that it must be approved by the Board.
If you could let me know what we, need to do to move this process forward pleaselet me know as soon as possible.
So that there is no confusion, I have entered into a joint venture with Dr. Hong that is called Sanda- Guthrie LLC. That : is the entity that will be purchasingthe property.
Thanks so much for your t/ me and consideration regarding this matter.
Jim Outhrie
April 6, 2O04
StephenC. Thomas, P.E. - Chief of Operations
RIVERSIDE COUNTY FLOOD CONTROL AND WATER CONSERVATION DISTRICT 1995 Market Street
Riverside, CA 92501
Dear Steve:
This letter is to confirm the details of my telephoneconversation with you and Councilman Frank Schiavone on Friday, April 2, 2004.
It is understood that you have no objectionto our goingforward with the public hearing on thel 6 acre property that is adjacent to the Alessandro Wash. We fully understand that there is an on- goingnegotiation to purchase the property owned by Riverside County Flood Control. We may not be successfifl in a £mai purchase; but, Riverside County Flood Conlxol has agreed, in a prior letter, to sell the 16 acres under certain circumstances which have yet to materialize.
It is also our understandingthat urfless a written response is received from Riverside County Flood Control stating that they do not want to go forward with the public hearingincluding their property, we will assume tha't they have no objection. The meeting set for April 8th will then be postponeduntil April 22, 2004.
We appreciatethe time and effort that you contributed to this issue. It is my intent to continue to move forward with the purchasethis properly as expeditiouslyas possible.
Thank you again for your continued cooperation.
Respectfully,
SANDA- GUTHRIE L. L.C.
Jim Cmthfie
Parmer
JDG:dg
ATTACHMENT E
BEST MANAGEMENT PRACTICES
Best Management Practices ( BMPs) Selection Criteria
Project Characteristics: The final phaseof the Tract 28728 consists of a residential area of 25 lots with an average lot size of 1 acre and some undevelopedarea. This will be an exclusive neighborhood of large homes and private streets well maintained by homeowners' association. Grounds surroundingthe homes will be well landscaped and maintained. For the purpose of this study, the project was divided into two main areas.
Area A is in the North- West part of the project. It is bounded by "A" Street to the West and phasel to the North. Area A encompasses a drainagearea of approximately 18.7 acres. It mainly consists of a natural wash just south of phase 2 of this tract. Flows from 4. 4-acres area of phase2, enter this natural wash. This flow is dischargedthrough a 24- inch pipe under Century Hills Drive to continue down the natural wash. Except for discharge from 154- feet long section of street A' the site is undeveloped. The discharge flow rates will be equal to or less than the existing dischargeflow rates resulting from the undeveloped site.
Area B includes large home sites of 1- acre. Area B encompasses a drainage area of approximately 49.6 acre, s. Flows from this area are routed through a filtration basin just West of " B" Street and South of Century Hill Drive and into the natural wash just south of CentuD Hill Drive. The dischargeflow rates will be equal to or less than the existing discharge flow rates resulting from the undeveloped site.
Off- site flows from the undeveloped area, just West of" A" street are assumed to be developedarea with 1- acre lot size.
Site Factors
Slopes: The natural flows are essentially North- South directions. Average slopes are less than three percent
Water Table: In this part of Riverside County the water table is generally Iow.
Soils Permeability: Soil survey for Western Riverside Area Californiai and Hydrology Manual prepared by Riverside County Flood Control and Water Conservation District were, used to determine the soil t3(pe in the area. Types of soil in the area are BdC, MmC2, FbC2 FcD2, and FcF2'. Please see attachment 1.
It is a mixture of sandy loam, sandy clay load, weathered granite, indurated hardpan, loam, clay and tonalite. This type of soil is ideally suited for infiltration BMPs such as infiltration basins. With this type of soil, the basins will drain in less than 48 hours. This will prevent the water from stagnatingand preserve storage capacity for subsequentrain events.
Proximity to Wells: No drinking water wells are known to be present less than 500 feet from all site boundaries.
Climatic Regions: Riverside County has Mediterranean type of climate with long dry season. Rains usually fall in winter and can be quite heavy at time. Generally rainfall is low. Thus wet ponds are not suitable BMP for this area as they would require some continuous flow ( dry weather source) to keep them from stagnating or developing odor and mosquito problems. Provision of the continuous flow of water is also economically not feasible, as the site is located in semi- arid region where cost of water is high.
Maximum Depth: Infiltration BMPs are suitable as the type of soil in the area provides optimal pollutant removal condition. Basins are designed so that water drains out ( infiltrates) in less than 48 hours.
Landscape Enhancement: The infiltration basin will be visually attractive and during some periods can serve as a park like area. Given the typical rainfall pattern in Riverside County, this open area should be available for recreational use most of the year.
Pollutant Removal Capability. This final phaseconsists of homes with large lot size in an exclusive area. Home- owners' association will be maintaining streets and common areas within the community. Trash and debris are not expected to be strewn about the ground. Thus it is not necessary to provide inlet trash rack to the drainage system. All facilities will be used daily and maintenance will be continuous. The floors and side slopes of the infiltration basins will be planted, irrigated and maintained to promote a dense turf ~ vith an extensive root growth in order to enhance infiltration, prevent erosion and consequent sedimentation of the basin floor, and to prevent invasive weed growth. Through the maintenanc~ program the vegetation growth will not be allowed to exceed 18 inches in height in the infiltration basins.
Contributing Watershed Area: Off- site flows from phase 1 and 2 enter the project in undeveloped natural wash and continue through the same wash through a RCP under Century Hill Drive.
Environmental Impact and Enhancement:
Low Flow Maintenance: Infiltration BMPs, which are selected for this site, can contribute significantly to groundwater recharge and may be able to help the watershed better mimic its predevelopmenthydrologic behavior.
Habitat Creation: The discln,arge flow rates will be equalto or less than the existing discharge flow rates resulting from the undeveloped site.
Conclusion: Infiltration BMPs is selected for this site. BMPs was designedto mitigate storm water runoff from the 85th percentile 24- hour runoff event determined as the maximized capture storm water volume for the area. The calculations and references for each areas are detailed in the attachment that follows. The infiltration