Background

The District was originally established in January 1929 as a “water control and improvement district” and was later converted to an “irrigation district” in June 1984. However, because it is located in a highly urbanized area, both municipal and agricultural users depend on the system for their water supply. The District delivers raw water to the
cities of Elsa, Edcouch, La Villa, Mercedes, Weslaco, and the North Alamo Water Supply Corporation, as well as to an estimated 350 agricultural accounts in the far western portion of Cameron County and the eastern portion of Hidalgo County.

Water is diverted from the Rio Grande to the main canal by the District’s pumping station located in Mercedes. Its water system consists of approximately 20 miles of unlined canals, 55 miles of lined laterals, 250 miles of pipeline, two re-lift stations and three 200-acre-foot storage reservoirs.

Recent system losses from the canals and reservoirs due to evaporation, seepage, canal charging, and leakage total approximately 34,000 acrefeet per year, while system efficiency is reported at 70%. Repair and replacement of conveyance structures is urgently required in order to conserve water and reduce the substantial losses due to the age and
condition of the existing system.

Description

This project will consist of the following five project components:

1. International Boundary and Water Commission (IBWC) Siphon Repair. Rehabilitation of up to 500 feet of siphon under the floodway channel south of Mercedes, by installing an Insituform liner inside the concrete pipes.
2. Arroyo Colorado Siphon Repair. Rehabilitation of approximately 600 feet of siphon under the Arroyo Colorado south of Mercedes and just north of the IBWC siphon, by installing an Insituform liner inside the concrete pipes.
3. Anacuitas Aqueduct Repair. The elevated aqueduct next to Expressway 83 in Mercedes will be shored up with a levee requiring approximately 45,000 cubic yards of earthfill, while concrete will be used to fill the overflow drop structure
   currently spilling water to one side of the aqueduct. Drainage of the area will be addressed by placing two culvert structures underneath the aqueduct and through the proposed levee.
4. Canal Lining. One mile of the main canal located northeast of the aqueduct will be covered with a synthetic liner.
5. Automation of “K” Lateral. Replacement of six existing vertical gate structures with new automated vertical gates and enhanced gate support structures, as well as installation of 14 depth sensor stations for monitoring water flow levels.

Benefits

The project will improve operational efficiencies not only in terms of annual operation and maintenance expenditures, but also with respect to energy and water conservation. Water savings are expected to average 27,883 acre-feet a year, while energy savings are estimated at 2,365,601 KWH/year as a result of reduced pumping requirements.