Lake Conroe is a 21,000 acre lake in Montgomery County, Texas, United States. Even though it is named Lake Conroe, only a small portion of the lake is in Conroe, Texas. Most of the lake is in unincorporated Montgomery County. The lake lies on the West Fork of the San Jacinto River, just west of Interstate 45 off of State Highway 105 in Montgomery and Walker counties.
The lake runs through classic East Texas Piney Woods forests. Water quality is generally good, with an average depth of 20.5 ft, and a maximum depth of 75 ft. The controlling authority of the lake is the San Jacinto River Authority. The City of Houston owns a two-thirds interest in the lake; the SJRA owns one-third. The lake extends about 21 mi in length and covers 20118 acres with 5000 acres in Sam Houston National Forest and capacity of 430,260 acre.ft. Lake Conroe was conceived in 1970 as an alternate water supply for the city of Houston. The lake was completed in January 1973, and it was filled on October 31, 1973.more