Lake Lowering - Reduce Flooding

During Hurricane Harvey, the San Jacinto River Authority (SJRA) released almost 80,000 cubic feet per second from the Lake Conroe Dam. This amounted to ONE-THIRD of all the water coming down the highly populated corridor between Humble and Kingwood. Massive damage resulted.

How Lake Lowering Policy Started

Almost 6,000 structures along the West Fork flooded. That number includes more than 1,100 between Lake Conroe and Porter. Forty-four percent of all the businesses in the Lake Houston Area Chamber experienced damage. The release inundated entire subdivisions. They included Forest Cove townhomes, Barrington, Kingwood Cove, Kingwood Greens, Kings Harbor, and Town Center. Large parts of other subdivisions flooded, too. Some more than two miles from the West Fork.

After touring the damage, Governor Gregg Abbott directed the SJRA to reduce flooding. The SJRA established a Flood Management Division. It also adopted a temporary policy of lowering Lake Conroe in the rainiest months of Spring and during the peak of hurricane season.

The extra capacity provides a buffer against flooding downstream.

What is the Policy? How Long Will It Last?

The policy is temporary while the City of Houston works to add more gates to Lake Houston. Lake Houston can release only 10,000 cubic feet per second while the gates on Lake Conroe can release 150,000, 15X more.

The policy has evolved over time. The current one represents a compromise between upstream and downstream residents. It will last through the end of 2023 and may be adjusted after that.

The current policy states:

Normal conservation pool level for Lake Conroe is 201 feet mean sea level (msl). For the spring season, beginning April 1, the COH may call for the release of water from Lake Conroe to lower the lake level to 200.5 feet msl, or six inches below normal pool. If the lake is already at or below 200.5, then no water would be released. After June 1, the lake is allowed to return to its normal level of 201’ msl.
For the fall season, beginning August 1, the COH may call for the release of water from Lake Conroe to lower the lake level to 200.5 feet msl, and after September 1, the COH can call for an additional release to reach 200.0 feet msl. This means the target is six inches below normal pool in August and one foot in September. If the lake is already at or below these targets, then no water would be released. After October 1, the lake is allowed to return to its normal level of 201’ msl.
During either the spring or fall lowering, if a major storm event is predicted to impact our region, the COH may initiate an additional release to create more storage capacity by notifying SJRA in writing.
All water released as part of this program comes from the COH’s 2/3 share of permitted water supply in Lake Conroe and must be requested by the COH. SJRA staff coordinate with COH staff on the details and timing of any releases. Coordination with COH involves ensuring that a Lake Conroe release considers releases from Lake Houston.