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located nearby. These inputs would be subtle and difficult to discern from other sources (i.e., snowmelt infiltration). Groundwater in hydraulic connection with the Colorado River was detected in well 5E-20. This well is located approximately 750 ft south of the river and was the only well not to go dry during the monitoring period. Depth to groundwater in SE-20 remained fairly static averaging 3.6 ft bgs over the last three months (April through June), dropping 0.19 ft over this period. Groundwater levels in this well did not reflect an increase associated with spring high river stage. Increases were not reflected either because monitoring period did not extend long enough into June or diminished 1999 spring flow conditions truncated the extent associated high groundwater reached outlying areas from river. The other two wells transecting this site area, 5E-21&22, were not screened as deep as 5E-20 to intercept the water table and therefore went dry prior to end of monitoring period. 2.4.2 Wetland Delineation Hydrogeologic investigation indicates that much of the wetland present at the proposed gravel pit area is the result of irrigation practices and is therefore not within COE jurisdiction. A revised wetland boundary was identified on the basis of hydrogeologic data. The original wetland boundaries in the vicinity of Monument Creek are not influenced by the findings of the hydrogeologic investigation. The revised wetland boundary is shown on Figures MP-1 and W-1. The boundary includes the imgation tailwater ditch along the south edge of the proposed gravel pit (approximately 1.45 acres) and 4 ponded areas in the area of the proposed Processing Site (approximately .OS acres). The ponded areas, shown as wetland islands on Figures MP-1 and W-1, appear to be the result of previous excavations at the site, possibly performed to explore gravel resources. Spring flow supports wet meadow conditions and groundwater recharge in localized areas along s ections of the tailwater ditch. Based on extrapolated study results, approximately only 20% of the 1.45 acre wetland peripheral to the tailwater ditch would be strictly considered to be jurisdictional. However, the project proponent elected to accept the entire 1.45 acre area as a jurisdictional wetland to avoid further delineation expense. 2.5 Conclusions Groundwater levels decreased in direct response to irrigation water being withheld from site areas historically irrigated, levels dropping>2.Ito>3.9ftbgsovermonitoringperiod. Groundwater inputs from artificial recharge via irrigation appear to dominate site wetlands water budget. These discharge wetlands showed seasonal to semipermanent pond permanency over past irrigated growing seasons but went dry early in monitoring period when irrigation water was withheld from site.