Caddo Lake Institute

Environmental Flows Project

Progress /Acknowledgements / Supporting Documents / Meetings and Workshops


The Environmental Flows Project (the Project) was initiated in 2004 by the Caddo Lake Institute and the Nature Conservancy (TNC) in partnership with U.S. Army Corps of Engineers and others.  

The Project was started after the State Legislature made the decision that no new water rights would be granted for protection of flows in rivers, lakes and bays.  Instead, the state proposed, and enacted in 2007 a law (Senate Bill 3) to provide a process for setting aside water for instream flows in Texas. That law endorsed the process that was being used by the Project.


Goal and Objectives

The Project seeks to assure adequate instream flows to sustain the ecological, recreational and economic values of Caddo Lake, its watershed and the larger Cypress Basin.

To reach its goal, the Project has three objectives:

* Official State Recognition of the Need to Protect the Recommended Environmental Flow Regimes Developed in this Project:  State action in support of these flow regimes, such as: 1) inclusion of the flow regimes as a goal for the environmental water needs in the regional and state water planning process, or 2) a set-aside of water for these flow regimes.

* Implementation of Strategies to Provide the Flow Regimes Where They are Currently Not Met:Examples of such strategies include a permanent change in the operations of Lake O’ the Pines to provide the flow regimes and an increase in the level of storage in that lake to provide additional water for the flow regimes.

* A Long-Term Program for Adaptive Management:  A program for monitoring conditions over the long-term, with periodic reevaluations of the recommended flow regimes and the expected outcomes.



Based on a series of meetings with natural resource experts and stakeholders from the basin, the Project developed  recommendations for "Building Blocks" or "environmental flow regimes" that mimic the natural flow patterns with month, season and year variations.

A number of studies were conducted both to test the early recommendations and build a baseline for future reference.  In 2011, the U.S. Army Corps of Engineers and the Northeast Texas Municipal Water District (NETMWD) committed to implementing the flow regimes for Big Cypress Bayou with releases of water from Lake O' the Pines for a five-year test period, to the extent water is available.  In exchange, the Project committed to carry out a number of experiments and to monitor conditions  in Big Cypress Bayou and Caddo Lake to evaluate the benefit of the releases.  One of the experiments is the reintroduction of the American paddlefish. Monitoring projects include tracking changes in soil moisture and vegetation in areas inundated by the recommended high pulse flows.    

In the fall of 2016, the results of experimentation and monitoring will be used by the participating experts and stakeholders in the 5th Project Workshop to reevaluate the recommended flow regimes, make any appropriate changes and develop plans for future work.



The Project is relying upon: 1) the experience of the TNC-Corps of Engineers’ Sustainable Rivers Program across the country; 2) the methodology developed by the National Academy of Sciences for the State of Texas for protection of environmental flows; and 3) the generosity of a number of landowners on whose land the Project has monitoring programs.

The Project is also indebted to the many experts and stakeholders who have brought their expertise, experience, and perspectives on the work of the Project.

The Project would not be possible without the generous assistance of the U.S. Army Corps of Engineers, U.S. Fish and Wildlife Service, U.S. Geological Survey, the state natural resources agencies of Texas and Louisiana, NETMWD and TNC.

Major funding was provided by the U.S. Army Corps of Engineers, U.S. Fish and Wildlife Service, NETMWD, a number of individuals and the following foundations:

  • Coypu Foundation
  • Jacob and Terese Hershey Foundation
  • Hollomon Price Foundation
  • Meadows Foundation
  • Cynthia and George Mitchell Foundation
  • Skiles Foundation
  • Kelcy Warren Foundation


Supporting Documents

General Documents
Historic Studies of Caddo Lake, Cypress Basin
Major Project Reports
Field Studies
Other Documents


Additional information on Caddo Lake and its watershed can be found on CLI's data website -

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