Laserfiche WebLink
Morton Lakes Substitute Water Supply Plan Renewal <br /> January 10, 2025 <br /> Page 4 of 14 <br /> acre. Depletions from this stage will consist of evaporation, dewatering, and gravel <br /> production. <br /> In accordance with the letter dated April 30, 2010 (copy attached) from the Colorado <br /> Division of Reclamation, Mining, and Safety ("DRMS"), all sand and gravel mining operators <br /> must comply with the requirements of the Colorado Reclamation Act and the Mineral Rules <br /> and Regulations for the protection of water resources. The April 30, 2010 letter from DRMS <br /> requires that you provide information to DRMS to demonstrate you can replace long term <br /> injurious stream depletions that result from mining related exposure of groundwater. The <br /> DRMS letter identified four approaches to satisfy this requirement. <br /> In accordance with approach nos. 1 and 3, you have indicated that a bond has been obtained <br /> for the new Morton-Holton Lakes site that can cover the cost of lining, to prevent the <br /> exposure of groundwater. The current bond amount for the new Morton-Holton Lakes site is <br /> $4050,000.00. <br /> Depletions <br /> The projected depletions for Stages 1, 2, 5, 6A, 613, 6D, 7A and 7B result from evaporation, <br /> dewatering, dust control, water used to wash the mined product, water lost in the mined <br /> product, and reservoir construction at Stage 5. <br /> Evaporation <br /> The Applicant proposes to replace evaporation from exposed groundwater at the Morton- <br /> Holton site based upon evaporation atlases in NOAA Technical Report NWS 33 and the State <br /> Engineer's Office ("SEO") monthly distribution factors for sites below 6,500 feet, as shown in <br /> attached Table 1. Gross annual evaporation at these gravel pit locations is estimated to be <br /> 44.27 inches per year based on the NOAA NWS 33 Evaporation Atlas mapping. Net <br /> evaporation is defined as gross evaporation less the consumptive use of water by vegetation <br /> that naturally occurred at the site prior to construction of the pit. The historical <br /> consumptive use was assumed to be equal to the effective precipitation of 9.25 inches, <br />