2020-08-05_PERMIT FILE - M2020008

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SSGM V✓W V✓. S 9 n1-1 11 C C O M The NWI mapping, which shows much of the western portion of the Parcel as wetlands, means that prior to developing those areas, the burden of proof would be on Scott Contracting to prove to the Army Corps that the wetlands are either(a) supported entirely by irrigation water and therefore non-jurisdictional, or (b) no longer wetlands. In general, no more than 0.5 acres of direct wetland impact can be permitted without going through the extensive Army Corps Individual Permit process, which is incompatible with effective development on the Parcel. However, documenting that the Parcel no longer contains wetland characteristics would allow full development on the site. Removing irrigation and upstream flows from being directed on the Parcel and documenting a loss of wetland conditions are the most common way to accomplish this goal. In addition, groundwater pumping is not regulated by Section 404, and indirect impacts to wetlands due to an adjacent pit dewatering operation are not regulated by Section 404 either (Army Corps, T. Morse, pers. comm.). Therefore, although initial gravel pit dewatering in the eastern portion of the property will depresses groundwater in adjacent wetlands and contribute to a loss of wetland conditions, that activity is not regulated and does not require a permit under Section 404. A dewatering permit from the Colorado Department of Public Health and Environment (CDPHE)—Water Quality Control Division (WQCD) is, however required for dewatering operations. Recommendations Based upon these initial wetland and groundwater modeling evaluations, we recommended that Scott Contracting proceed with a two-pronged approach to remove the hydrology which supports wetlands on the Parcel: • Remove all irrigation water discharge onto the property • Maintain dewatering in a pit located in the upland eastern portion of the property, which could depress groundwater throughout the property. Monitoring of wetland conditions on a quarterly or bi-annual basis would allow Scott Contracting to document that all activities are in compliant with Section 404 regulations and would also document the point at which wetlands disappear from some or all the Parcel. At that point Scott Contracting could apply to the Army Corps for an Approved Jurisdictional Determination (AJD), which would formally recognize that the NWI wetlands are no longer present, and that development of the remainder of the property can proceed without Section 404 permitting. 3