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  <br />Mr. Paul Bruss, P.E.  <br />April 12, 2018  <br />Page 3 of 6  <br />  <br />DEPLETIONS  <br />   <br />The Rocky Ford East pit is in the process of reclamation.This SWSP renewal is to replace                  <br />depletions resulting from evaporation from the ponds and from the water contained in the               <br />previously mined product.During the reclamation,dewatering will occur from one pond to              <br />another within the mining boundary,since three of the four ponds will be completely               <br />backfilled and the fourth reduced in size.   <br />   <br />Evaporative depletions have been calculated using the maximum surface area of the pit,              <br />which is 26.6 acres of post-1981 exposed ground water surface area.   <br />   <br />Depletions have been lagged back to the Arkansas River using a Glover analysis with the                <br />following inputs:  <br />   <br /> Distance from river: 2,975 ft   <br /> Distance from alluvial boundary: 7,675 ft   <br /> Transmissivity: 71,000 gpd/ft  <br /> Specific yield: 0.2  <br />   <br />You have calculated the total lagged depletions to be 105.29 acre-feet for the period August                <br />1, 2017 through July 31, 2018 (see attached Table 3A).   <br />   <br />REPLACEMENTS  <br />   <br />Valco will continue to utilize a combination of leased water and historical ditch credits to                <br />make replacements to the river.A five-year lease dated August 1,2017 was obtained to                <br />provide replacement supplies during this SWSP approval period for between 75 and 82              <br />acre-feet from the Upper Arkansas Water Conservancy District (“UAWCD”).The minimum and             <br />maximum amounts of leased water for each year of the agreement are shown in the table,                 <br />below.  <br />  <br />  <br />  <br />Additionally,Valco owns 2 shares in the Rocky Ford Ditch,which have been determined to                <br />yield 25.72 acre-feet per year of consumptive use for the purposes of this plan and will be                  <br />used to offset depletions at this pit.   <br />   <br />