Publication

Downstream Transport Rates of Passively Drifting Particles in the Rio Grande Low Flow Conveyance Channel

URL: https://webapps.usgs.gov/mrgescp/documents/Dudley%20and%20Platania_2001_Downstream%20transport%20rates%20of%20passively%20drifting%20particles%20in%20the%20Rio%20Grande%20low%20flow%20conveyance%20channel.pdf

Date: 2001/10/24

Author(s): Dudley R.K., Platania S.P.

Publication: Final report prepared for U.S. Bureau of Reclamation, 17 p.

Abstract:

The Middle Rio Grande (Velarde, NM to Elephant Butte Reservoir) is a highly regulated system designed to efficiently transport water to downstream users. The Rio Grande within this region is fragmented by two reservoirs (Cochiti and Elephant Butte) and three diversion dams (Angostura, Isleta, and San Acacia). There are also about 834 miles (1,342 km) of irrigation channels and 386 miles (621 km) of interior and riverside drains that form a matrix across the Middle Rio Grande Valley. This large-scale flood irrigation network (operated by the Middle Rio Grande Conservancy District, MRGCD) diverts and transports large quantities of water.

The Low Flow Conveyance Channel (LFCC), a man-made structure, was designed with the intent of efficiently transporting Rio Grande water during periods of low flow from San Acacia Diversion Dam to Elephant Butte Reservoir. Water was to be artificially diverted into the LFCC where it would travel parallel to and on the west side of the Rio Grande. This hydrologic project was completed in 1959 with a maximum capacity of about 2,000 cfs. Operation of the LFCC was ceased in April 1981 following problems with siltation within the channel near the headwaters of Elephant Butte Reservoir. Operations were resumed for a 15 month period between 1983-1985. Only several brief periods of experimental operations have been conducted in the 1990s. An outfall was constructed in 1997 for the purpose of returning seepage water from the LFCC to the Rio Grande at a point about 9 miles (14.5 km) downstream of San Acacia Diversion Dam. However, no water from the LFCC returns to the Rio Grande downstream of the outfall. Flow in the lower reaches of the LFCC, near San Marcial, NM, averages 200-300 cfs because of irrigation returns and notable groundwater seepage (i.e., LFCC is below elevation of bed of Rio Grande).