Managing Water Supply Systems Using Climate Projections

Climate change impacts

Tampa Bay in Florida, USA, faces a number of climate change issues, including drought, more frequent and intense storms, flooding, and saltwater intrusion. In the early 2000s, Tampa Bay Water started using groundwater for surface water shortages caused by prolonged periods of drought. However, groundwater irrigation has reduced the water level of local wetlands and lakes, negatively affected ecosystems, and caused the loss of wildlife habitats.

Adaptation activity

Tampa Bay Water recognizes that it needs to supply customers as well as protect the environment. In order to do this, tools for predicting reductions in surface water supply are necessary.
Projections (see Note 1) provided by the NOAA Climate Prediction Center (see Note 2) were used to assess temperature and precipitation patterns for periods of weeks to months. A particularly significant factor affecting Florida's climates is the El Nino Southern Oscillation (ENSO) (Note 3), which has been found to be a reliable indicator of Florida's wet and dry periods. Using research based on ENSO data, forecasts and significant insights could be provided for water management purposes. As a result, water supply administrators are able to make decisions on groundwater conservation and ecosystem protection in a timely manner during periods when there is a shortage of surface water.

Reservoirs for storage surface water and a desalination plant to replenish freshwater have also been constructed in anticipation of dry periods, and to increase drought resilience. Today, Tampa Bay Water utilizes a combination of three resources: surface water from rivers and reservoirs, groundwater from wells, and desalinized seawater from Tampa Bay. The use of these different water sources incurs different respective costs, and this has to be taken into account when delivering supply.

Outputs / Expected benefits

Factoring in ENSO has enabled economically and environmentally viable storage and intake, pumping, and desalination plant operations. While it is difficult to balance the three water sources to keep costs down while maintaining a high quality of life, climate projections have made management easier. In addition, new strategies using multiple water sources have resulted in the recovery of natural resources in many locations.

Footnote
(Note 1) Based on past meteorological observations, present conditions of the oceans and computer modeling studies.
(Note 2) NOAA (National Oceanic and Atmospheric Administration)
https://www.noaa.gov/
(Note 3) Natural phenomenon in which water temperature fluctuates over periods of months, and years, in the central Pacific Ocean.