LCRA’s operation of the Highland Lakes is governed by the 2015 Water Management Plan.
The plan, approved by the Texas Commission on Environmental Quality in November 2015, protects the water supply for firm customers – mainly cities and industrial users – and allows LCRA to quickly adapt its operations as drought conditions change. The plan establishes three sets of operating conditions to determine the availability of interruptible stored water, which is primarily used by agricultural customers in Colorado, Wharton and Matagorda counties. It also sets two dates – March 1 and July 1 – for determining the amount of interruptible stored water available for first and second crop.
Under the Water Management Plan, water availability for interruptible customers is largely determined by the combined storage in lakes Travis and Buchanan on March 1. Combined storage in lakes Travis and Buchanan stood at 1.96 million acre-feet on March 1, 2017, so the full allotment of stored interruptible water (202,000 acre-feet) allowed under the Water Management Plan will be available for first crop agriculture for the Gulf Coast, Lakeside and Pierce Ranch irrigation operations this year, if needed. Water for the Garwood irrigation division is supplied separately, under terms of the Garwood Purchase Agreement. A separate determination will be made later in the year on water availability for second crop. Water will be released gradually and only to the extent the needs for agriculture cannot be met with the natural flow of the Colorado River. The needs for agriculture and the flow of the river depend on weather conditions during the irrigation season.
LCRA conducts water supply operations consistent with the Water Management Plan and all other applicable water rights and agreements. During water supply operations, needs for water are first met with the natural flow of the Colorado River - to the extent allowable - to reduce the amount of water used from the Highland Lakes. Water also may be released from any of the Highland Lakes as needed to manage excess flood waters.
Releases from Lake Austin are made when needed to meet downstream customer needs, and to supplement the flow of the lower river when needed to meet environmental flow requirements. Customers that take water from the Colorado River downstream of Lake Austin include four irrigation systems (the Lakeside, Garwood, Pierce Ranch and Gulf Coast systems), the Fayette Power Project, industrial customers in Matagorda County, the City of Pflugerville, Decker Creek Power Station, Lost Pines Power Park and others. Environmental flow requirements include TCEQ requirements to maintain instream flows along the lower Colorado River and supply freshwater inflows to Matagorda Bay and estuary.
Releases from Lake Travis are made when needed to replace water that is released from Lake Austin, and to supply water to customers along Lake Austin. Customers that take water from Lake Austin include the City of Austin, West Travis County Public Utility Agency and others.
Releases from Lake Buchanan are made when needed to replace a portion of the water that is taken or released from Lake Travis, and to supply water to customers along lakes Inks, LBJ, and Marble Falls. Customers that take water from the Highland Lakes above Mansfield Dam include the City of Austin, City of Cedar Park, Travis County WCID No. 17, City of Leander, Lakeway MUD, Ferguson Power Plant and others.