Conroe sits on several geologic layers of underground aquifers, which supply the city with fresh drinking water. Due to the rapid development of the land and increased population of Conroe and the surrounding area, the groundwater supply is being withdrawn faster than it can be replenished. As a result, the Lone Star Groundwater Conservation District, which oversees groundwater usage in Montgomery County, mandated that Conroe reduce its groundwater usage by 30 percent of 2009 amounts by January 1, 2016. As part of the groundwater usage reduction plan, the San Jacinto River Authority began in September 2015 to supplement Conroe's groundwater supply with surface water pumped from Lake Conroe. The SJRA charges the city usage fees to cover the cost of pumping and treating the water. On August 27, 2015, the City of Conroe filed a lawsuit against the Lone Star Groundwater Conservation District, claiming that the LSGCD did not have the authority to limit the city's groundwater usage. The city also refused to pay SJRA water usage fee increases in 2016, resulting in a separate lawsuit filed by the SJRA against the city. The LSGCD and Conroe reached a settlement agreement in January 2019, while the SJRA case was dismissed in June 2020.