Background
The Arroyo Colorado is an ancient channel of the Rio Grande that extends eastward for about 90 miles from near the City of Mission through southern Hidalgo County to the City of Harlingen in Cameron County, eventually discharging into the Laguna Madre near the Cameron-Willacy county line. The watershed of the Arroyo Colorado drains approximately 700 square miles and generally consists of coastal plain that slopes gently toward the Gulf of Mexico.
The Arroyo Colorado Watershed is the major drainage-way for approximately two dozen cities in the area, with the exception of Brownsville. Additionally, almost 500,000 acres in the three counties are irrigated for cotton, citrus, vegetables, grain sorghum, corn and sugar cane production. Thus, much of the watershed is sustained by runoff and return flows from these areas, including urban wastewater discharges, irrigation and other agricultural return flows, stormwater runoff and base flows from groundwater.
Use of the water in the Arroyo Colorado for municipal, industrial or irrigation purposes is severely limited because of poor quality conditions. Salinity concentrations in the Arroyo typically exceed the limits considered desirable for human consumption, as well as, those acceptable for irrigation of crops. Furthermore, water quality and fish tissue testing have found that: (1) low dissolved oxygen levels have impaired the fish community and other aquatic life downstream from the Port of Harlingen; (2) elevated levels of pesticides (chlordane, toxaphene and DDE) have resulted in a fish consumption advisory upstream from the Port of Harlingen; and, (3) bacteria levels are occasionally elevated indicating a potential health risk to people who swim or wade in the Arroyo upstream from the Port of Harlingen.
Goals and Objectives
The Agricultural Issues Workgroup was created by the Arroyo Colorado Watershed Steering Committee to develop the agriculture portion of the Watershed Action Plan to restore water quality in the Arroyo Colorado Watershed. Stakeholder involvement within this group as well as other planning groups have identified needs specific to water quality protection and improvement for the agricultural community. Therefore, Texas Water Resources Institute (TWRI) proposes to work through Texas AgriLife Extension Service to implement an educational program within the three-county area to address these issues related to agriculture production identified by the stakeholder groups.
Specifically, the educational program will serve two purposes. First, AgriLife Extension will utilize its already developed resources and delivery system to educate producers on proper management and production techniques. Programs will address cotton, grain sorghum, sugar cane, citrus and vegetable production and proper nutrient management practices including a soil testing campaign. Second, AgriLife Extension will promote programs associated with Arroyo Colorado water quality protection. For example, cost-share programs to support implementation of best management practices and technologies previously developed in the area did not reach full potential due to a lack of awareness among producers. AgriLife Extension will be able to both promote these programs and provide education on the proper use of these technologies following installation.
Funding Source
Funding provided by the Texas State Soil and Water Conservation Board as part of a Clean Water Act Section 319(h) Grant.
