HomeMy WebLinkAboutSite Certifications - 02/09/1995Northern Engineering Services, Inc.
February 8, 1995
Glen Schleuter
City of Fort Collins
Stormwater Utility
235 Mathews
Fort Collins, CO. 80522
RE: Drainage Certification
Hampshire Pond P.U.D.
Project Number: 9317.07
Dear Glen:
We have completed our review of the as -built drainage a [in at the
above referenced project. This certification pertains to Phases and II ly, which
includes Storm Sewer Line "A", the detention pond and, on and off -site Swales' B and
A respectively.
A field inspection of the drainage and erosion control appurtenances was
conducted on Wednesday November 30, Wednesday December 14, 1994, January 11
and February 8, 1995. The following is synopsis of the observations made during the
field visits.
1) Temporary erosion control such as straw bale dikes and gravel inlet
filters are in place and appear to be functioning efficiently.
2) Rip -rap at the outlet of Storm Sewer Line "A'' along Swale "A" and at the
outlet of the detention pond discharge pipe are all in place.
3) Swale "B", adjacent Drake Road, is sodded and landscaped with a
capacity well exceeding the minimum required.
4) Swale "A", located in the southeast corner of the site,
also has capacity well exceeding the minimum required. The concrete
trickle pan is at a design grade of 0.50%.
5) The 15" RCP in Swale "B" has a full flow capacity of 4.43 cfs. The
anticipated 100-year flow at the culvert is 2.23 cfs therefore, the pipe has
ample capacity.
420 S. Howes • Suite 202 • Fort Collins, Colorado 80521 • (303) 221-4158 • Fax (303) 221-4159
Hampshire Pond P.U.D. February 8, 1995
Drainage Certification Page 2
6) The overall site grading is within reasonable tolerances.
7) Street grades are very near design elevations and, therefore, street
capacities are acceptable.
8) The detention pond has adequate volume to detain the anticipated
stormwater runoff calculated from the SWMM modeling. An emergency
overflow swale and, overflow pipe fitting have been provided to convey a
pond spill toward the south to Spring Creek,
9) Hydroseeding of the side slopes of Drainage Swale A has been
completed.
10) Visual confirmation of the high point located in Water Blossom Lane,
east of the intersection of Water Blossom Lane and Willow Fern Way.
To the best of my knowledge, belief, and opinion, the drainage facilities were
constructed in accordance with the design intent of the approved drainage report and
construction drawings. If you require additional information or analysis regarding this
project please contact me at 221-4158.
Sincerely,
NORTHERN ENGIN
Michael F. Jones, P.