Laserfiche WebLink
EXHIBIT G - A (addendum) <br />IGNACIO PIT CODMG Permit 0 M-1992-054 1/04/06 by MRC <br />Preliminary Dreinage Assessment -Summary <br />The followirg sumadzes the basis for calculating the rapadry of typical detention ponds within the mining phases. <br />The area considered is determined by the 20 acre ma~dmum disturbance discussed in the permit application. <br />Detention of stormwater within all mining phases will be managed such that no discharge occurs. <br />A more formal drainage analysis is cumen0y under way in the preparation of a Sfomm2ter Management Plan. <br />A wpy of this plan will be submitted to CODMG when completed and accepted by the Cdorado Department of Health - <br />WaterQuality Control Division. <br />Q =Flow, C = Runff Coeffident, I =Intensity, A =Area <br />Runoff Calculation <br />Total Site Area 20 AC. <br />Runoff Cceffident (Overland -Assume Heavy Soils @ 1-5% Slp) <br />t00% Pervious @ 0.30 <br />C,~ = 0.30 x 1.25 = 0.375 <br />Q cfs =CIA = (.375) (5.4) (20 Ac.) = 40.5 cfs <br />Q vol (cf) =CIA = (.375) (2.2/12) (871.2ksf) = 59.895 cf <br />Detention Pontling Caoatlly <br />Proposetl depth of pond = 3.,§B <br />Surtace Area (SA), then is (59,895 cf / 4.5) = 13.310 sf <br />[I.e: (SA)'rz = 115.4 ftj <br />Thus, a canelation can be applied wherein for each arxe of disturbed land approximately 3,000 dof detention cepaaty <br />is constructed and maintained. <br />