NarrativeEXISTING CONDITIONS
The RSI site is located at the northeast corner of Flying Cloud Drive and Great Plains Blvd. The
existing site was previously constructed with a building and parking lot for an animal daycare and
overnight facility.
The site has both hydrologic soll groups B and C on-site. The predominate soil group for the site
is hydrologic group C. The site drains from north to south and drains to the Flying Cloud Drive ditch
along the north side of the road and eventually drains to across the road and to Rice Lake. The site
ranges in elevation from 798 on the north side to 726 on the south side.
The property is currently sittinB empty and not being utilized. The vegetation is a combination of
grass and trees.
PROPOSED CONDITIONS
The site is being proposed to be developed into four (4) buildings of 20,000 square feet each
with an access off of Flying Cloud Drive in the southeast corner of the property. The proposed
development will collect storm water from the building and drive and direct the stormwater into a
stormwater pond in the southwest corner of the property through an on-site storm sewer system. The
proposed site has been modeled using HydroCAD with Atlas 14 stormwater events for the 1,2,10 and
100-year events. The proposed and existing stormwater run-off rates for the site are as follows:
YEAR EXISTING PROPOSED
5.99 c.f.s 5.71 c.f.s
2 YEAR 8.37 c.f.s 6.94 c.f.s
10 YEAR 10.23 c.f.s
1OO YEAR 45.21c.t.s.18.76 c.f.s
The infiltration for the site will be provided with a filtration pond adjacent to the stormwater
pond. The proposed site will have 2.79 acres or 121,532 square feet of impervious surface. The
impervious surface is required to infiltrate the first one inch of stormwater runoff. The proposed
infiltration required is 12L,532 sq ft x 1 inch/12inch or 10,128 cublc feet. The infiltration volume
provided is 10,220 cubic feet.
The proposed stormwater plan meets the city stormwater requirements. we have attached the
HydroCAD model for your review. lf you have any questions, please call.
Sincerely,
James R Hill, lnc.
Joel G. Cooper P.E.
President
1 YEAR
23.65 c.f.s.