Answering Your Questions About League City's Drinking Water
With Houston’s recent boil water notice due to a power outage at their East Water Purification Plant, League City residents have questions about where League City gets our drinking water from and what measures we have in place if a similar scenario impacts our drinking water.
What are the primary sources of League City’s drinking water?
League City’s drinking water includes surface water and ground water (wells).
Current available capacities
- Surface Water: 28 million gallons per day
- Ground Water: 12 million gallons per day
Surface Water from Two Sources
Surface water supply provides the City’s primary source of potable drinking water on any given day. The Trinity River is the raw water supply for the City of Houston’s Southeast Water Purification Plant, which is where League City gets approximately 80 percent (22.5 MGD) of our surface water. The remaining 20 percent of surface water supply (5.5 MGD) comes from the Brazos River. This is the raw water source for Gulf Coast Water Authority’s Thomas Mackey Water Treatment Plant, located in Texas City. League City is one of the few cities in our area with two sources of surface water supply from two independent river systems. This strengthens our redundancy options during emergencies.
Ground Water as a Supplemental Source
Ground water is an important component of the City’s water supply inventory. The City currently has eight active wells totaling 12 MGD of available capacity. These wells and are located throughout the city. Ground water can be used for emergency operations and to supplement surface water distribution operations during high demand periods.
What Happens During an Emergency?
League City’s water distribution system is robust, and we have many options to ensure the delivery of safe drinking water during times of emergency. This is the result of aggressive Capital investment into the City’s water system over the past 12 years.
Infrastructure improvements—including additional surface water capacity, additional ground water capacity, ground storage, elevated storage, booster pump station capacity, and water line additions—provide redundant water delivery during emergencies (like what the City of Houston just experienced) and help prevent potential boil water notices. In the event of a power outage, we have generators at our pump stations.
Water restrictions can also be used to reduce system demand to manageable levels during emergency water system operations. This can effectively reduce water usage by 10 to 50 percent depending on the seasonal impact to system demand.
When are Boil Water Notices Issued?
Boil water notices are mandated by the Texas Commission on Environmental Quality (TCEQ) when water systems fail to meet certain safety standards. While boil water notices can be a nuisance to residents, they are a vital public health safeguard and a major reason why our nation’s Public Water System is considered the safest in the world.