Beyond water supply augmentation: Environmental benefits of infrastructure investment for a regional water supply system

This paper presents an examination of the environmental benefits of enhanced surface water production on groundwater systems in a metropolitan region, Tampa Bay Region, in Florida in the United States. The regional water supply agency, Tampa Bay Water, has decided to expand facility production capacity of its surface water treatment plant by 20 million gallons per day (MGD), starting in 2028. This capacity expansion has the potential to significantly reduce groundwater production in future years. Reduced groundwater production can lead to higher water levels in both the Surficial aquifer and the Upper Floridan aquifer, mitigating potential adverse environmental impacts such as ecosystem degradation. A simulation–optimization framework is used to determine production from different supply sources under two scenarios: the baseline scenario (Scenario A), and the supply augmentation scenario (Scenario B). Results reveal a considerable increase in the annual reliability of the water supply system, while simultaneously maintaining higher groundwater levels. Specifically, for the annual median water level in the Surficial aquifer, increased water levels in Scenario B are observed at 25 out of the 41 (61%) stations. Similarly, tor the 25th percentile water level in the Surficial aquifer, increased water levels occur at 30 out of the 41 (75%) stations. In the Upper Floridan aquifer, higher water levels in Scenario B are expected at 13 out of 18 (72%) monitoring sites. The approaches presented here can serve as a blueprint for similar efforts worldwide, particularly in regions facing growing water demand, groundwater depletion, and environmental degradation.