Laserfiche WebLink
RECEIVED EXHIBIT G <br /> Water Information APR 3 0 2024 <br /> Colorado Division of Reclamation, <br /> Introduction Mining and Safety <br /> The Cache la Poudre River is located northeast of the Timnath Connell Pit property with portions <br /> of the floodplain encroaching on the site. Other water resources on or near the site include the <br /> Box Elder Ditch which previously bisected the permit area and has been relocated to its eastern <br /> edge. Irrigation laterals associated with agricultural production, groundwater recharge, and <br /> augmentation return flows to the Cache la Poudre River are also located on or near the perimeter <br /> of the site. The southern edge of the site includes two unlined groundwater recharge ponds. <br /> Colorado Youth Outdoors (CYO) owns and operates the property south of LCR 36 and includes <br /> unlined mining pits reclaimed as groundwater ponds. The property is used for youth/family <br /> outdoor education activities including camping, fishing, and shooting/archery. <br /> In the vicinity of the Timnath Connell Pit, the Cache la Poudre jurisdictional floodplain has a <br /> divided flow path; portions of the floodplain are delineated on both the east and west sides of the <br /> site as illustrated on Flood Insurance Rate Map (FIRM) Number 08069C1013F (National Flood <br /> Insurance Program, effective December 19, 2006). A more recent jurisdictional floodplain map <br /> of the area has been developed by the Colorado Water Conservation Board (CWCB). Although <br /> still under review, the CWCB map is currently being used by Larimer County for floodplain <br /> development regulation (FIRM Number 08069C1013G, revised preliminary December 20, <br /> 2021). The 100-year floodplain and floodway delineation from this FIRM still includes a <br /> divided flow path at the Timnath Connell Pit site and is shown on the Water Resources Map, <br /> Exhibit C-4 and illustrated on the attached FIRM. <br /> In 2023, a letter of map revision (LOMR) was submitted to local regulating agencies within <br /> Larimer County and the Town of Timnath, along with the Federal Emergency Management <br /> Agency (FEMA) for review and approval. Based on river hydrology and hydraulics and current <br /> ground topography, the LOMR (Case No. 23-08-0780P) effectively redefines the jurisdictional <br /> floodplain boundary near and within the Timnath Connell Pit property. The LOMR has been <br /> approved by all reviewing agencies and the new floodplain delineation will become effective for <br /> FIRM Number 08069C1013F on August 5, 2024 (revised FIRM attached). The revised 100-year <br /> floodplain and floodway are shown on the Water Resources Map, Exhibit C-4. All work <br /> performed in the regulatory floodplain will conform to the Town of Timnath Floodplain <br /> Development Regulations. <br /> Water Requirements and Replacement <br /> Water consumed during mining and reclamation activities will include evaporation from exposed <br /> groundwater in dewatering trenches, a dewatering sump or settling basin, recharge ponds, <br /> operational water losses from dust control, and water retained in product hauled off-site. <br /> According to the 2024 Substitute Water Supply Plan Renewal (Williams and Weiss Consulting, <br /> LLC to the Colorado SEO dated February 14, 2024, estimates of the net annual evaporative <br /> depletion from mining operations in the permit area is 34.95 acre-feet. This depletion is based <br /> Timnath Connell Pit <br /> DRMS 112 Permit Amendment Application Page 17 <br />