Documentation submitted to Corps by GLO altered state-approved computer model – misrepresented impact to the Bay

The Gilchrist Community Association (GCI) and the Gulf Coast Rod, Reel and Gun Club (the Club) today released a study of the impacts of the closure of Rollover Pass upon East Bay that demonstrates that significant harm will result to East Bay if Rollover Pass is closed as proposed by the General Land Office (GLO) of the State of Texas.

This new study prepared by Larry Dunbar, P.E., was commissioned after documents contained in the files of the Corps of Engineers revealed that TxBLEND, the official State of Texas computer model for Galveston Bay, had been modified by a consultant to the General Land Office in a manner that eliminated all sources of freshwater inflow into East Bay. Due to this modification, this model predicted no adverse impacts from the closure of Rollover Pass on East Bay fisheries. However, the exact opposite result is shown when the official state model is correctly utilized, as shown in the Dunbar report. In turn, this erroneous model was relied upon by the U.S. Army Corps of Engineers in its decision to issue a permit allowing the closure of Rollover Pass.

According to Jim Blackburn, the attorney for GCI and the Club, “This modification of the computer model conceals the impacts of this closure upon East Bay. It should be very troubling to those concerned about the Texas coast and coastal recreational fishing. The Corps should have the best information before them as they attempt to resolve whether to issue this permit or not.”

East Bay is the easternmost arm of the Galveston Bay system lying between the Bolivar Peninsula and the mainland of Chambers County. Rollover Pass was opened in 1955 by the Texas Game and Fish Commission, the predecessor to Texas Parks and Wildlife Commission, on property owned by the Gulf Coast Rod, Reel and Gun Club. The stated purpose of the opening of the Pass was to improve bay water quality and salinity, enhance fish migration into Rollover Bay and East Bay, perpetuate state fish and wildlife resources, and improve local fishing conditions. Rollover Pass is adjacent to the community of Gilchrist on the Bolivar Peninsula.

In 2010, the General Land Office applied to the U.S. Army Corps of Engineers for a permit to close Rollover Pass. On August 10, 2012, the U.S. Army Corps of Engineers issued a permit allowing the GLO to close the Pass. The Gilchrist Community Association and the Gulf Coast Rod, Reel and Gun Club filed suit against the Corps of Engineers and the General Land Office in federal court in Galveston on April 19, 2013.

The computer model at issue is called TxBLEND. It has been used in bay and estuarine modeling throughout the Texas coast as well as specifically in Galveston Bay. The State of Texas’s bay and estuary planning process utilized the TxBLEND model in the official report of science committee studying Galveston Bay under Senate Bill 3. In the Senate Bill 3 process, the officially-approved TxBLEND model included inflows from Oyster Bayou, Spindletop Bayou and the Gulf Intracoastal Waterway in eastern Chambers and Jefferson Counties that empty into East Bay at the eastern extreme of the Galveston Bay system. However, when the GLO utilized the TxBLEND model in support of its permit to close Rollover Pass, the GLO’s consultant removed the inflows into East Bay from the model.

“The effect of the removal of the inflows into East Bay is to eliminate the effects of freshwater on the salinity of East Bay. In most of our bays, we need all the freshwater inflow that we can get, but East Bay is different. With Rollover Pass closed, most of East Bay becomes isolated from the Gulf and is more likely to be harmed by too much freshwater rather than too little” added Blackburn.

According to the report released today, if the officially approved version of the TxBLEND model is used, East Bay is shown to become extremely fresh after the closure of Rollover Pass. Rather than predicting salinities in the desired 15-25 part per thousand range as shown in the GLO report, the un-modified TxBLEND model shows salinities ranging from 0 to 15 ppt after the closure of Rollover Pass.

Again, according to Blackburn, “The difference in these results is huge. Rather than being ideal for saltwater fish and shellfish, East Bay will become too fresh and will suffer a diminished fishery. The important point is that the GLO hired a consultant who modified the model to remove inflows and then submitted the results to the U.S. Army Corps of Engineers to convince the Corps to issue a permit to allow the closure of Rollover Pass. This was based, at least in part, on the results of that modified model indicating ‘no problem’. Such manipulation of an approved computer model is scientifically wrong, and I hope to show it is legally wrong.”

For Immediate Release January 8, 2014
For Further Information Contact Jim Blackburn, 713-524-1012

Coastal Update – Rollover Pass
By Jim Blackburn