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HomeMy WebLinkAboutComments PWE 12/20/2005 " DRC REVIEW PUBLIC WORKS REVIEW CITY OF SPRINGFIELD, OREGON DRC REVIEW: December 20,2005 Mever Park Cluster Subdivision 12- Lot Cluster SubdIvisIon Prepared by Steve Barnes, P.E TENT A TIVE SITE PLAN SUB2005-00065 PRJ2004-00006 Planner: KIth Gale The above application was reviewed by Public \V orks Engineering. The following conditions shall be addressed before approval of the Final Site Plan. SANITARY SEWER Fl11dl11g SectIOn 32.100 of the SDC requires that samtary sewers shall be installed to serve each new development and to connect developments to eXIstmg mams. Fl11dl11g A sanitary sewer mamfold with 11 new connections within 10-20 feet IS proposed wIthm a proposed I4-foot "PUE" on Sheet 3 of 4. They should be located wIthm a sl1mlar SIzed Pnvate UtilIty Easement, since CIty Mamtenance has no desIre to accept responsIbIlIty for this non-standard connection \.. Condition: Prior to approval of the final site plan, the applicant shall provide a private utility easement for the new wastewater line (with connections) between the existing manhole and the new 6-inch cleanout. STORMW A TER MANAGEMENT (W ATER QUALITY) Fmdl11g Under Federal regulation of the Clean Water Act (CW A), Endangered Species Act (ESA), and NatIonal Pollutant DIscharge ElIminatIOn System (NPDES), the CIty of Spnngfield IS required to obtain, and has applIed for, a MunicIpal Separate Stonn Sewer System (MS4) permit. A provision ofthis permIt reqUIres the City demonstrate efforts to reduce the pollution in urban stormwater to the MaXImum Extent Practicable (MEP). Fl11dl11g Federal and Oregon Department of Environmental Quality (ODEQ) rules reqUIre the CIty'S MS4 plan address SIX "MImmum Control Measures." Mml1num Control Measure 5, "Post-Construction Stonnwater Management for New Development and Redevelopment," applies to the proposed development. Finding. MmnTIum Control Measure 5 requires the CIty of Springfield to develop, Implement and enforce a program to ensure the reductIOn of pollutants in stormwater runoff to the MEP. The CIty must also develop and implement strategIes that include a combmation of structural or non-structural Best Management Practices (BMPs) appropnated for the community. Findl11g Mimmum Control Measure 5 reqUIres the CIty of Spnngfield use an ordmance or other regulatory mechamsm to address post constructIOn runoff from new and re- development projects to the extent allowable under State law. Ref,'1llatory mechamsms used by the CIty include the Spnngfield Development Code (SDC), the CIty'S Engmeering Design Standards and Procedures Manual (EDSPM) and the future ? Stormwater FacIlItIes Master Plan (SFMP). sf, k{ ~ 32- I J /6 C c.) d Fl11ding. As required m SectiC050 (5)~e SDC, "a development shall be reqUIred to employ drainage management practIces approved by the Public Works DIrector and conSIstent WIth Metro Plan polIcies and the Engl11eenng Design Standards and Procedures Manual." Findl11g Section 3.02 of the City's EDSPM states the PUbIC Works Department wIll accept, as mtenm design standards for stormwater qualIty, water qualIty facIlItIes designed pursuant to the poliCIes and procedures of eIther the CIty of Portland (BES) or Umfied Sewerage Agency (USA), also know as the Clean Water Services (CWS). Findmg SectIOn 3.03.3.B ofthe City's EDSPM states all publIc and pnvate development and redevelopment projects shall employ a system of one or more post-developed BMPs that m combinatIOn are designed to achieve at least a 70 percent reduction in the total -suspended solIds in the runoff generated by that development. Additionally, SectIOn 3.03.4.E of the manual requires a minimum of 50 percent of the non-buildmg rooftop ImpervIOUS area on a SIte shall be treated for stonnwater qualIty Improvement usmg vegetative methods. Findmg' To meet the reqUIrements of the CIty's MS4 permit, the Springfield Development Code, and the City's EDSPM, the applicant has proposed a 120-foot long "stormwater mfiltratIOn swale". The swale has an ODOT Type 'D' overflow catch basm WhICh is acceptable for stormwater quality treatment per the City of Portland's (BES) Stonnwater Management Manual. Finding Routme mamtenance of the Drainage swale and mlet and outlet structures is reqUIred to ensure a 'functional water qualIty umt, and continued complIance wIth CIty standards. Condition: Prior to approval of the final site plan, the applicant shall provide a Grass Seed Mix for the Bottom of Swale that complies with the Portland BES for frequently inundated conditions. The soil beneath the first 20-feet or so of the swale should be amended with clay or provided with a liner to provide some bio-swale contact time prior to commencing infiltration. One or more flow spreaders should be provided within the swale system. Condition: Prior to approval of the final site plan, the applicant shall provide an operations and maintenance plan to the City for review to ensure the long-term maintenance and operation of the proposed stormwater quality system. Condition: A current approved review of the application for stormwater discharge shall be submitted from Oregon Department of Transportation STORMW A TER MANAGEMENT (QUANTITY) Fmdmg: Plans show one downspout locatIOn for each dwellIng umt connected to the stonn dramage mfiltratIOn system. ' Findmg: ApplIcant has acknowledged on Sheet 4 of 4 that runoff from Lot 12 wIll need to be treated prior to discharge. SITE SOILS: Fmdmg: The applIcant has lIsted sIte soIls (#119 Salem Urban Land Complex) on Sheet 1 of 4. PAVEMENT SYSTEMS: Finding: The proposal calls for extension of A Street with a private driveway servmg 10 small cluster homes. Pavement section and turn-around have been approved for home and fire access. Sidewalks and Driveways Fmding: The proposal calls for paved surfaces able to wIthstand an 80,000 pound load. Findmg: A new 5 foot concrete sIdewalk IS proposed to be continued from the Northern side of A Street to the North side of the pnvate dnveway. A set of ramps IS proposed to gUIde foot traffic to the North-side sidewalk. Condition: US Postal Service has requested coordination for a neighborhood mailbox unit for similar developments. Confirm with the local Postal Service that a mailbox unit will specifically not be required for this development. Street Trees Fmdmg: One eXIstmg 16" cedar tree IS shown on the plans near the Mam Street Frontage that might qualIfy as a street tree. Condition: Paragraph 32.050 requires street trees to be spaced approximately 30- feet on center along the property street-side frontage. 6 qualifying street trees spaced approximately 30 feet on center are required to be shown on the plans for approximately 173 feet of street frontage on Main Street. Easements Findmg. A 7 foot PublIc UtIlity Easements IS shown on Sheet 2 of 4 for the MaIn Street Frontage. An eXIstmg 7 foot PUE IS shown on the neIghbonng propertIes throughout the entIre Eastern and Northern Lot boundanes. ApplIcant plans to relocate the eXIstmg pnvate irrevocable jomt-use stormwater, utIlIty and maIntenance easement along the Eastern 5 feet of the property FIndIng. The pryvate jomt-use samtary sewer lInes shown require an easement IdentIfied In the condItIOn for Samtary Sewers- above. Trash Enclosure Fmdmg: No Trash enclosure (dumpster) locatIOn IS shown on the plans. Condition: If added later, a dumpster area must be properly screened and hydraulically isolated (covered) and connected to sanitary sewer to eliminate infiltration of stormwater. LDAP Condition: An approved Land Drainage Alteration Permit (LDAP) application is required for this development. Normally, the application is required two or more weeks prior to any land disturbance.