8353 Civil Review 1 031504March 15, 2004
Yelm Terra LLC
4200 6th Ave SE Suite 301
Lacey, WA 98503
RE: Civil Engineering Review No. 1
Yelm Terra Subdivision Engineering Review
City of Yelm Project No. CIV-03-8353-YL
Dear Mr. Chamberlain
I have reviewed the plans submitted. The following are comments from the above referenced plans and need to be addressed on the future submittal. I have organized these comments by
general category. If you have any questions, I have also included a set of redlined plans to clarify these comments.
Site Plan:
The roadway connection to the north needs to be designed as a local access residential roadway.
Please revise the roadway bulb outs to meet the City of Yelm standard detail for this design. The narrowed roadway section should be no longer than 20’ from the angle point in the roadway.
Mailbox locations and detail need to be shown on the plans. These locations need to be approved by the Yelm Postmaster. Please submit a site plan with the postmaster signature with
the locations shown and the number of boxes.
Grading and Drainage Plan:
Need to add a note to the plan stating that the stormwater easements cannot be build upon.
It appears that from station 1+00 to 2+53 on the western side of the roadway needs a catchbasin to convey the stormwater.
Catchbasin #7 is greater than 5’ and should be type 2.
Catchbasin #1 inverts do not match pipe slopes.
The northeast corner of the roadway at lot 40 appears to have ponding stormwater and is not being conveyed by a catchbasin.
The pipe length from CB #9 to CB #10 in not consistent from plan to profile.
Please add all the existing and proposed centerline elevations to the bottom of the profiles.
Catch basin spacing needs to be verified. The maximum allowable roadway length draining to a catch basin is 500 feet.
Catchbasin #19 appears to be outside the flow line.
104th Loop SE needs to be designed using vertical curves instead of angle points.
The existing survey shows some type of conveyance system going from lot 14 toward lot 92. What is this?
Show existing elevations on 105th Ave SE and proposed flow line elevations.
Verify that there will be a 12’ drive lane and 2” shoulders on the opposite site of 105th Ave SE right of way centerline.
The 104th Loop SE structural section is missing the crushed rock callout.
The roadway names will be reviewed by the building official.
Stormwater Report:
The rainfall design storms from the TCDDECM are 2.8” for the 2-year and 6.15” for the 100-year. Pease revise the calculations.
The basin plan in the construction drawings show 24.25 acres, and the stormwater report states the stormwater basin area is 13.12 acres or 16.36 acres. Please revise the numbers to
be consistent or explain the difference in the report. All project area needs to be accounted for.
The storm shed calculations need to be submitted. The TCDDECM requires that the engineer calculate both the prescriptive and computerized method for sizing the storm water facilities
and using the most restrictive method.
Please add to the report the volumes of each wet pond, infiltration pond, infiltrative surface etc.
Demonstrate that the 100-year storm can be infiltrated in 48 hours. See TCDDECM for requirements.
It appears that the live storage in the wet ponds will not be able to drain to the infiltration ponds with the berms at the design height.
Water Plans:
The water line will need to be extended from lot 24 to 105th Ave SE.
The water line will need to be extended from the intersection of 105th Ave SE and 104th Loop SE to the property line.
The water line will need to be extended from lot 59 to 105th Ave SE.
The southern portion of 104th Loop SE does not meet the fire hydrant spacing requirement of 600’ between hydrants.
Add a fire hydrant at Sta. 10+50 along 105th Ave SE.
All highpoints in the water line will be required to have a blow off/air-vac assembly.
Connect the watermain from Sta. 11+53 to Sta. 12+85.
Show existing waterline in 105th Ave SE on plan and profile.
The water meters should be located 3’ behind the right of way line. This is measured to the center of the box.
Remove detail 6-4.4 from the plans.
Modify detail 6-6 to reflect the meters behind the right of way line.
STEP Sewer Plans:
The step sewer main needs to be extended from lot 24 to 105th Ave SE.
A third valve needs to be added to the intersection of 3rd and 104th Loop SE.
The step sewer main needs to be extended from lot 59 to 105th Ave SE.
The step sewer main located in the southern portion of 104th Ave SE can be downsized to 2” in size. (Sta. 55+00 to Sta. 65+00)
The sewer step boxes should be located 3’ behind the right of way line. Measured to the center of the box.
The step sewer main needs to be designed and installed in 105th Ave SE. The step sewer main size shall be 4” in size.
All high points in the sewer main lines need to be fitted with an air release assembly.
Street Lighting Plan:
Street light locations should be located 3’ behind back of curb.
Please see the revised street lighting locations on the redlines.
Conditions of Approval and Misc:
The conditions of approval will be reviewed when they are issued to make sure that all conditions have been addressed on the plans. If there are any comments, you will receive them
during the subsequent review.
The MDNS conditions must be met prior to construction permit. Please review these conditions and add any required items to the plans. (tree and vegetation plan, etc)
When the conditions of approval are issued please add them to the cover sheet of the plan set. This is a requirement of the City of Yelm.
Please review and revise your engineering drawings. When you resubmit please send 4 revised sets of plans and a letter stating how you have address the review comments. If you have
any questions or comments, please call me at (360) 458-8438 and I will be happy to further assist you.
Respectfully
City of Yelm Community Development
Jim Gibson
Development Review Engineer
Cc: Grant Beck, City of Yelm
Tim Peterson, City of Yelm