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04-0175 Civil Review 1 120405 City of Yelm Community Development Department 105 Yelm Avenue West P.O. Box 479 Yelm, WA 98597   December 14, 2005 Amy Head Parametrix – Lacey Office 8770 Tallon Lane NE Lacey, WA 98516 RE: Griffin Plat (John’s Meadows) – SUB - 04- 0175 - YL Initial Review of Civil – Site Construction Documents Dear Amy: The City of Yelm has completed the initial review of the proposed subdivision. This application included: Subdivision Construction Documents dated 10/28/05 Subdivision Drainage Report We have reviewed the plans for compliance with the City of Yelm Development Guidelines, the DOE Stormwater Manual and general standards of civil engineering practice. The following comments need to be addressed before the plans may be approved for construction. Our comments are summarized below: Site Plan and Cover Sheet (sheets 1 thru 3) The land use conditions of approval need to be added to the cover sheet. This is a City of Yelm requirement. At your request I can email you a word document with the conditions. The Approved for Construction block needs to read Development Review Engineer instead of Public Works Director. The mail box locations need to be shown on the site plan. These mailboxes shall be CBU units only. Individual mailboxes are not allowed. You are also required to submit a site plan to the Yelm Post Office for the postmaster’s signature. Please submit the signed site plan to Community Development Department with you next submittal. The intersection of Middle Road and Road B should be designed per the COY detail 4-8B with a 35’ curb return radius. Why is the Middle Road Line table a series of short line segments instead of the single bearing and distance? Erosion Control Plan, Details and Notes (sheets 5 and 6): The temporary construction entrance detail length should be 100 feet instead of 50 feet. Grading and Stormwater Plan (sheets 7 thru 16): The stormwater pond should have been designed per the 1992 Department of Ecology Stormwater manual. Please change the callouts on page 7 to reflect this. The tracts should be labeled with letters not numbers. The berm between the pond cells shall have a min. top width of 6’. Please install a pipe between cell 1 and cell 2 of the wet ponds. This pipe should be sized to pass the 100 year storm and be placed below max water level. The water will use this pipe to equalize the water elevations between the cells. The rip rap overflow should remain incase the pipes ever plug. The pond setbacks are 10’ from all property lines and tract lines except for the south tract line which is 5 feet. This is measured from the top or toe of slope depending on the design of the pond. The design has not met this requirement. I had 2 discussions about this with the designer and made him aware of this early on in the design process. The overflow spillway needs to have a geotextile under the rock lining. The bulbouts tend to be a problem for drainage if the roadway centerline is less than 1%. Please add flowline elevations to the bulbouts. Add another set of catchbasins at A18+50. Revise the sidewalk around cul-de-sac “C” to reflect the cul-de-sac on road “A”. Page 15 general note number 1 should read…”in accordance with the City of Yelm Standards. Remove the reference to other manuals. The roadway sections on sheet 16 refer to private roads. All streets shall be public roadway. See COY detail 4-7. STEP Sewer Plan (sheets 17 thru 25): An Air Release Assembly will be required at Sta. A13+60. Please eliminate the slight dip in the hydraulic grade at Sta. A16+40 and no Air Release Assembly will be required at this high point. No Air Release Assemblies are required at Sta. C42+6.41 and A20+7.62. A note should be added to the plans about ground water and trench dewatering for the sewer system at Sta A14+24. Extend the sewer mains all the way to the end of the cul-de-sac. Locate the end of line cleanouts in the planter strips. The sewer line on Road A shall connect to the existing sewer main at the connection point of Road A at the subdivision to the Northwest. Many of the sewer general notes placed on the sewer sheets contradict the City of Yelm’s Standard Sewer notes. Please remove the notes that conflict with the City Standard Notes. The COY does not allow deflection of pipes unless approved by the inspector. Water Plan (sheets 26 thru 34): Use one service line for lots 47-48, 45-46, 28-29, 16-17, split service line at meter setters. Move blow off assemblies to planter strip. Air release assemblies must exit above ground 12” through side of box, not through lid. This is a change since the details were adopted. The COY does not allow deflection of pipes unless approved by the inspector. Please locate fire hydrant assemblies in the cul-de-sacs and at the intersection of Middle Road and Road B. Extend the water mains all the way to the end of the cul-de-sac. Locate the airvac or blowoffs in the planter strips. The water details have been updated. Please remove the expired details and add the new water details. Illumination Plan (sheets 35 and 36): No comments at this time. The street light general notes do not apply to this street light installation. Landscape and Irrigation Plan (sheets 37 thru 45): This review will be completed and a separate letter will be sent. Middle Road Frontage Improvements (sheets 46 thru 48): The frontage improvements do not appear to be laid out on the revised construction centerline that was established by Willow Glenn Subdivision. As part of their project they acquired additional right of way from Mrs. Dotson and the adjacent properties. The project seems to shows the correct current right of way/property line for this project and the dedication shall be from the existing right of way. This is a confusing situation so please call me and we can talk about it. Please add a few more catchbasins to the Middle Road plan. With the flowline being as flat as it is, there needs to be adequate drainage for the roadway. The roadway detail will have to be revised per no. 36. Conditions of Approval: Please verify that you have met all the requirements stated in the Hearing Examiners conditions of approval. Please review and revise the plans to address the above referenced comments. When the project is resubmitted you will need to submit 4 sets of plans, 2 stormwater reports. The project engineer should include a written response with the resubmittal, indicating how all the review comments above have been addressed or responded to. This will significantly expedite our review of the project. If you have any additional questions or comments please do not hesitate to call or contact me at jimg@ci.yelm.wa.us. Community Development Department Respectfully, Jim Gibson P.E. Development Review Engineer cc. enc.