Five Reasons that the SJRA Seasonal Lake Lowering Should Not Be Allowed to Continue
A program initially sold to lake Conroe residents and regulators as temporary has been converted into a duration of at least five years without a firm stop date or firm milestones – only future review. The initial waiver allowing the dumping of water was premised upon the program being temporary and it was tied to completion of dredging of the West Fork – work which was completed in Fall 2019.
No technical study conclusively supports lake lowering as a materially effective mitigation for any downstream flooding. Two technical studies exist – one funded by the SJRA which concludes there is no material flood mitigation benefit downstream of Lake Conroe. However, it was only relevant to a boundary near I-45 about ten miles from the Dam – well short of the Lake Houston area. A second independent study (the Bleyl study) assessed the potential flood mitigation benefit in the Lake Houston area from lowering Lake Conroe by 2 feet. It also concluded that there was no material flood extent reduction from the lake lowering program in the event of a major rain event.
Arbitrary dumping of fresh water without technical proof of effectiveness to reduce flooding by the lowering program is not only wasteful it is a gross disregard of the SJRA’s main mission to conserve the full water resources of Lake Conroe. It sets a bad precedent that a natural resource can be wasted without a technical study that fully assesses the total benefits, costs, and negative impacts of a program.
The process of review of the lake lowering program was broken from the start and resulted in a charade that pitched groups of area residents against one another. Each only able to give three-minute pleas in a town hall format without allowing experts to adequately address the SJRA Board and key issues to be objectively considered. This format should not be allowed when making critical technical decisions that impact thousands of residents and businesses. The seasonal lake lowering program was enacted by a Board majority vote that did not follow the recommendations of its own technical experts.
The real problem is not Conroe lake levels but dam release rates that were needed to prevent dam failure as a result of a once in 1000 year storm – Hurricane Harvey. Lake Conroe’s contribution to the flood magnitude downstream of the dam during Hurricane Harvey was significant but it was far less than the other water sources flowing into the Lake Houston area. In over forty years of operation the Lake Conroe dam has held back much of the rainfall from over a hundred significant rain events. In only two cases has the dam release rate exceeded significant levels causing flooding and these two storms were rated as 500-1000-year rain events. Seasonal lowering will not prevent downstream flooding or large dam releases in the case of a catastrophic rain event. For lesser rain events history has shown that these can be handled with modest dam releases and without downstream flooding. Any impactful solutions must address the real issue which is the significant drainage problem in the Lake Houston Area.