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Livestock seater tank 6-b collects surface runoff, which is variable. When there is water present, <br />it is utilized by livestock and wildlife. The configuration of the impoundment is adequate to <br />support the intended use. <br />( c) Adequate safety acrd ucce.+:r to impounded water shn(! be provided .for prupnsed <br />users. <br />Adequate safety and access [o impounded water is provided for proposed users. The steepest <br />side slope into the impoundment area is approximately 4h:1 v. <br />(cQ [Barer impuunduren[s s/rn/! no[ result in the climinudon ojdre quality ur yrrun[iry of <br />water available [o water right holders jot ugriculnrrnl, irufasn•ial, recreutionnl, ar <br />donresric uses except in accordance with applicable S[cr[e law. <br />No diminution of the quality or quantity of water available [o water right holders occurs with <br />respect [o [his impoundment. Livestock water tanks with capacities below 2 acre-feet are exempt <br />from seater rights. <br />(c) The design, construction and nrairrrerrarce ojpernrarent inrpoundnren[s no! meeting <br />the site requirements oj-1.O.i.9(3) shall ncbieve the nrarimrurr design regnirenrents of <br />U,S. ,S'oil Coaservertion Sen~ice Public Standard 378, "bnpoundrneutr ", C'nluradu. <br />.Irmuury, 1989. Copies of [his publication crre mailable n[ the gffrce gJ'!he Division <br />Jiu• public urspectian. <br />Livestock +va[er tank 6-b does no[ meet [he size requirements of 4.05.9(3) - Large <br />Impoundments. Based on the survey of the impoundment conducted November 25, 1997, the <br />maximum area at high water will be 0.056 acres and there is no dam or embankment. The design <br />requirements of U.S. Soil Conservation Service Public Standard (SCSPS) 378 - "Design Criteria <br />I'or Cxc:rvated Impoundments" were followed for the analysis of this impoundment. <br />(n The inrpowulmenr spillwrw .cyslem shall also be designed in accordance with the <br />requirerrreuLC of Rrde =1.05.6(3)(4) or -1.0~.6(3)(e). The design even[ requirement of <br />Rule d.05.6(.i)(b) shall be applied lu [hose nnpounduren[s nor meeting the sr_e or <br />other criteria of Ruler -1.(1.9(3), carless a !urger design event i.r required by dre <br />SCSPS 378, January, 1989. <br />The spilhvay system analyzed for 6-b is a single, grass-lined, open-channel spillway meeting the <br />requirements of 4.05.6(3)(e)(ii). As this impoundment does not meet the size or other criteria of <br />4.05.9(3), the design even[ specified by 4.05.6(5)(b) will be [he 25-year, 24-hour design storm. <br />SCSPS ~7R requires that this impoundment be designed to the 10-year, 24-hour design event. <br />SEDCAD+ +vas used to determine the peak Flow at the impoundment based on the 25-year, 24- <br />hour event. The contributing area was determined from 1:500 scale maps of the area. An access <br />road approximately 600 fee[ up-slope of [he impoundment diverts runoff above the road [o the <br />east, so the drainage basin for this impoundment is approximately 3 acres. The peak flow from <br />the 25-year, 24-hour event was determined to be 2.08 cfs. This peak Flow, and sun~ey <br />information was input into the SEDCAD+ Vegetated Channel Design Utility to determine [he <br />adequacy of the spillway system. The surveyed width of [he spilhvay channel is 58 feet with <br />side slopes of 20h:1 v. However, the Channel Design Utility will no[ accept a channel this large, <br />