WSP03343 - Laserfiche WebLink

Home Browse Search

, Water is also diverted into the non-project Percha and Bonita Laterals. The Percha Lateral comes off the east side of the river at the Percha Diversion Dam and the Bonita Lateral comes off the west side at Caballo Dam. The Garfield, Hatch, Angostura, and Rincon Drains are the main drainage facilities in the Rincon Valley. These facilities were constructed for the most part during the late 19108 and early 1920s. All discharge to the river in the Rincon Valley. The historical discharges to the river from these drains are discussed in Section 4 of this report. The major aquifer in the Rincon Valley is the flood-plain alluvium. It typically is 60 to 80 feet thick, consisting of a basal layer of gravel overlain by sand, silt, and clay. It extends over the entire length of the valley, but is not more than 2 miles wide. Although basin fill deposits of the Santa Fe Group underlies and borders the flood-plain alluvium in the Rincon Valley, they consist primarily of a thick sequence of clay. The development of irrigation wells in the flood- plain alluvium has been significant, but we have not been able to obtain specific data for the number of wells constructed or the amount of pumpage.3J Additional wells have been developed in narrow strips of alluvial fill in the tributary arroyos. Such wells provide not only supplemental water for project and non-project lands, but also sole sources of irrigation supplies. Yields for irrigation wells in the valley are reported to range from 320 to 2,360 gpm with an average of 1,050 gpm. Recharge to these aquifers is from irrigation, precipitation, and seepage from canals and the Rio Grande and its tributaries. Overall, the aquifer is reported to be in balance; however, the water table declines as much as 10-feet in dry years when the pumping tends to be high and the recharge tends to be low (Wilson and others, 1981, pp. 28- 32). Much of the ground water in the flood-plain alluvium has concentrations of total dissolved solids of more than 1,000 milligrams per liter (White and others, 1981, p.83), 3J Much of the limited data and information that are presently available relate either to the Mesilla Valley or to both the Rincon and Mesilla Valleys. This limited data and information are discussed later in this report section. r - (' ... ,""\ '" ..' v 2-9 ~--_.