Laserfiche WebLink
<br />inflow primarily is from a diversion ditch off the Garnet Canal on the east <br />side of the lake and from a small drainage ditch at the southwest end of the <br />lake (fig. 8). The State has water shares for the Garnet Canal and during <br />irrigation season can divert water into the lake from the Garnet Canal. <br />During the nonirrigation season (November through March), the diversion on the <br />Uncompahgre River for the Garnet Canal is closed. A small quantity of water <br />continues to flow through the Garnet Canal during the nonirrigation season <br />from irrigation drainage and seepage into the canal. The headgate on the <br />diversion ditch usually is open throughout the year; therefore, there usually <br />is a continuous flow through the diversion ditch into the lake. There was <br />water flowing in the Garnet diversion ditch during every visit by project <br />personnel during the reconnaissance investigation. The maximum discharge <br />measured or estimated in the Garnet diversion ditch was about 1.5 ft3/s. The <br />continuous flow of water from the canal into the lake has been occurring only <br />since installation of a new headgate during the mid 1980's on the diversion <br />structure at the lake (Kenneth Moreland, Colorado Division of Parks and <br />Outdoor Recreation, oral commun., 1989). Apparently, the old headgate was <br />silted in much of the time, and no surface water would flow into the lake. <br />Since installation of the new headgate, there may be considerably more <br />flushing of the lake than in previous years. There may be small quantities of <br />drainage into the lake from nearby irrigated fields; and, because the lake is <br />in a minor depression, there could be shallow ground-water discharge into the <br />lake. The quantity of subsurface inflow into the lake is not known. <br /> <br />Outflow from Sweitzer Lake is over the spillway into a small, grass- and <br />brush-choked channel. Apparently, water in the outflow channel infiltrates <br />into alluvium and does not flow to the Uncompahgre River at the surface. <br />Water was observed flowing over the spillway during visits to the lake by <br />project personnel (November 1987 to August 1988) except during a visit in late <br />March. On rare occasions, water has been released from the lake through a <br />bottom outlet, but that outlet was not used during the period of the recon- <br />naissance investigation. <br /> <br />Ground Water <br /> <br />In the Uncompahgre River valley, aquifers in alluvial material and in <br />the Dakota Sandstone are the most used, primarily for live~tock watering or <br />for domestic use in rural areas without access to a municipal water system. <br />Well yields as large as 750 gal/min have been reported from a well completed <br />in alluvial material (Brooks and Ackerman, 1985). Alluvial ground water is <br />hydraulically connected to the Uncompahgre River and to canals. Most of the <br />ground water used in the valley is west of the Uncompahgre River. East of the <br />river, the alluvial material is not as suitable as a water supply because there <br />are fewer gravel beds and more shale in the material (Meeks, 1950). Shallow <br />wells east of the river may be in lenses of sand and gravel or broken shale <br />that store drainage from irrigated fields and seepage from canals, laterals, <br />and ditches (Meeks, 1950). Alluvial ground water can be more saline than <br />nearby surface water; much of the increased salinity might be from leaching of <br />salts by irrigation drainage. <br /> <br />18 <br /> <br />\ <br />