Laserfiche WebLink
f-CLARK ENGINEERING COMPANY □ 2815 WAYZATA BLVD. □ MINNEAPOLIS. MN. 55405 □ {612) 374-4740 <br />'f <br />rPAMlCSA>il| <br />^ANDfLiM C'CI <br />E V<t <br />JiV C enAuCMlR <br />v.c« dtni <br />C mARUSE HANSEN <br />5*« <br />^ * <br />^ <br />• . r <br />tAbRVG ».NMjRTRy <br />eauCI « AElit <br />AikX «tt <br />C/AviOS McESAC <br />A|V«<.Att <br />tlSLIt G REN‘.rMLt« <br />Atwactftc <br />i -V: •* <br />SKH/G/r "S '■ <br />- 3-(,-78- <br />March 3. 1978 <br />City of Orono <br />P.O. Box 66 <br />Crystal Bay, MN 55323 <br />RE: THE FARM AT LONG LAKE <br />Gentle.-nan: <br />The proposed plat, “The Farm at Long Lake", contains a drainage way v;hich <br />will be crossed by the drivev;ay to be constructed on Outlet C. It is <br />proposed to provide a corrugated metal culvert to accommodate this drain­ <br />age, Because there is a relatively large area drained into the plat from <br />the v;est and north a drainage study was conducted to determine possible <br />peak flows and adequate culvert sizes. <br />Because the backup of flood waters to a height somewhat over the top of <br />the lov/ point in the drivev;ay would not cause damage to buildings nor <br />flood basements, a design storm frequency of 10 years Is considered con­ <br />servative. <br />The watershed is divided into two parts. The first is that which drains <br />to Brown's Lake west of Brown Road and the second part is that which <br />drains from the north. The two parts have distinctly different runoff <br />patterns because the first has storage in the Lake and the second has <br />direct runoff. In a storm situation runoff from the north will peak <br />long before runoff from the west.' The attached drawing shows the pro­ <br />posed plat and watershed. <br />The outlet from the Lake is a 24" CMP culvert under Brown Road. It i; <br />estimated that a 10 year frequency sto»Tn of 60 minute duration will <br />raise the lake about 3 inches. This depth would contribute about 1.4 <br />cu. ft./sec. of flow. The northerly area will contribute an amount <br />peaking in about 20 minutes at a rate of about 18.5 cfs. <br />I <br />CONSULTING ENGINEERS <br />STRUCTURAL •CIVIL <br />LAND SURVEYING <br />400 SIBLEY <br />ST. PAUL. MN. 55101 <br />(612) 291-7000 <br />310 SOUTH LINCOLN STREET <br />ABERCEEN. S.D. 57401 <br />(OJ5) 225 3494