HomeMy WebLinkAboutFIRST CHOICE BANK - MINOR SUBDIVISION - 41-94A - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE RELATED DOCUMENTMr. Mike Herzig
1 st Choice Submittal
The conceptual location of the detention pond was suggested by the surface of the undeveloped site.
The existing site drained naturally to its northeast corner and the proposed configuration and grading
of site roads and parking areas around the new bank building substantiated the conclusion that this
was the best point from which to drain the detention pond to the Horsetooth Road gutter by gravity.
The berm and wall were placed to maximize the on -site volume available for detention. Preliminary
drawings of this intended design were reviewed with City personnel on several occasions. The location
of the sidewalk, at one time on top of the berm, now lowered next to the wall, and the widened
sidewalk at the corner of Horsetooth and Mitchell, resulted from these sessions.
It is important to note that the stormwater detention system, as designed, allows a release rate to be
held to or less than historical runoff from a 2 year storm so the development of the site does not
increase runoff to down stream facilities. The anticipated request for a variance for an increase in
flooding at the intersection of Horsetooth and Landings Drive will not be required.
Thank you for your attention to this matter. Please call if you have any questions.
Sincerely,
WATER, WASTE & LAND, INC.
Maurice H. Lutkin, P.E.
Manager, Civil Engineering Division
x/c: Glen Schlueter
WATER
WASTE
& LAND
February 7, 1994
2629 Redwing Rd. Suite 200, Fort Collins, Colorado 80526-2879
(303)226-3535
fax (303) 226-6475
Mr. Mike Herzig, P.E.
City of Fort Collins
281 North College
Fort Collins, Colorado 80521
RE: 1ST CHOICE BANK - SUBMITTAL OF UTILITY DRAWINGS AND A DRAINAGE AND EROSION
CONTROL REPORT FOR THE PERMANENT BANKING FACILITY (Southeast Corner of College
Avenue and Horsetooth Road)
Dear Mike:
We are submitting, for the City's review, the Plat, Utility Drawings, the Drainage and Erosion Control
Report and the proposed APO list for the referenced project. A landscaping and site plan prepared by
the architect will be included.
The drawings in the Utility set that will show details of the widening of College Avenue, Horsetooth
Road and the. Median at Horsetooth and Mitchell Drive, are incomplete awaiting additional information.
However, we understand that the City will review the Bank site drawings at this time so that portion
of the project can proceed while the planning and design work on the remainder is being completed.
The alignment of the sidewalk along Horsetooth Road is not according to City standards. An
explanation of how this and the berming and wall along Horsetooth and the west side of Mitchell Drive
evolved, follows. It will hopefully induce the City to approve this variation in standards.
By way of background, at the outset of the project we held several meetings with Stormwater Utility
to discuss the best approach to handling the runoff from the site and from College and Horsetooth.
Historically, stormwater from these locations ran east on the south side of Horsetooth eventually
ending up in Warren Lake. Along the way some of the water entered a piped system at JFK Parkway,
proceeded through the piped systems that handle the Marriot and surrounding development and then
contributed to the flooding that occurs from time to time at the intersection of Horsetooth and
Landings Drive. An obvious though costly approach was initially considered - a new storm sewer on
the south side of Horsetooth from the site to Warren Lake. This was deemed to be an unfair
imposition on infill development from the standpoint of cost. It was finally agreed that as much
stormwater as reasonably possible would be detained on site. The released runoff from the site and
the runoff from the adjacent streets would then be allowed to take the historical route to Warren Lake.
An analysis of the inlet and stub connection at the southwest corner of JFK and Horsetooth was to
be conducted to determine if any significant benefit would be realized from enlarging both so as to
divert more flow from Horsetooth gutter to the Marriot system. A prediction of the impact of increased
runoff from the developed site on the periodic flooding at Horsetooth and Landings Drive would then
be attempted and a variance requested for the impact. The need for some of these analyses was
eliminated as the final design of the drainage system evolved. This design is explained in the Drainage
and Erosion Control Report.
Consulting Engineers and Scientists