Large Water System Planning and Operation

Large urban areas face water supply challenges as they continue to grow. Houston, like many other large urban areas has been in a transition from primary dependence on groundwater to surface water. The transition began in the mid 1970's in order to control land subsidence in Galveston and Harris Counties, where valuable property has been lost. In order to develop and provide an adequate water supply without total dependence on groundwater, new surface water supplies must be planned implemented. Construction of surface water treatment facilities must be developed, coupled with the expansion of existing surface water treatment facilities and interconnection of transmission and/or distribution mains to ensure safe and reliable distribution systems operation. While groundwater will remain a valuable resource, but pumpage will be limited, primarily to meet peak water demand and provide service to areas where surface water is not available. The remainder of City of Houston water system consists of groundwater pump stations and associated groundwater wells which originally had minimal interaction with each other. Safety is also a major consideration in planning and operations of water supply, treatment and distribution system. The impact and response of two major storms, October 1994 and July 2001, will also be reviewed in this paper.