Lake Houston is a reservoir on the San Jacinto River, 15 miles northeast of downtown Houston, Texas, United States. The reservoir is the primary municipal water supply for the city of Houston. Situated between the communities of Kingwood, Atascocita and Humble on the west bank, Sheldon on the south, and Crosby and Huffman on the east. An earth…Lake Houston is a reservoir on the San Jacinto River, 15 miles northeast of downtown Houston, Texas, United States. The reservoir is the primary municipal water supply for the city of Houston. Situated between the communities of Kingwood, Atascocita and Humble on the west bank, Sheldon on the south, and Crosby and Huffman on the east. An earthen dam spans a portion of the southern bank along Dwight D. Eisenhower Park.