Miami, Florida

Warming temperatures and rising sea levels are expected to threaten southern Florida’s water resources over this century.  Since the beginning of the twentieth century average temperatures in Florida have increased two degrees to 69 degrees Fahrenheit, and springtime temperatures could increase another three or four degrees by 2100.  One consequence of these higher temperatures is expected to be increased evaporation of surface water supplies and reduced streamflows and groundwater supplies, and more frequent and intense droughts and storms.

Rising sea levels also put Florida at risk.  South Florida’s sea level has risen by twelve inches since 1846, and continues to rise at a rate of up to 16 inches per century.  The EPA predicts that by 2100 south Florida’s seas will be about 20 inches higher than their 1990 levels.  As a result, increasing amounts of saltwater will infiltrate inland groundwater sources and freshwater supplies, such as the Biscayne aquifer, posing a critical threat to the region’s drinking water supplies.

The Miami-Dade Water and Sewer Department (MDWASD) is taking part in proactive steps to maintain south Florida’s drinking water supply into the future. MDWASD is expanding its existing Water Conservation Program, which achieved a system-wide per capita reduction from 180 gallons per capita per day (gpcd) in 1995 to 158 gpcd in 2005. To increase water efficiency, the utility now offers the free replacement of old showerheads (using up to 5 to 8 gallons per minute) with efficient ones using only 1.5 gallons per minute.  The utility plans to give away 16,000 showerheads between 2006 and 2010, each of which is expected to save up to 35 gallons of water per day and rebates on the purchase of residential high-efficiency toilets and clothes washers. Twenty percent of the projected water demands for the next 20 years will be met from conservation.

In addition, MDWASD has developed a 20-year alternative water supply plan that will rely on reclaimed water, for groundwater recharge and irrigation, and the Floridan aquifer; to meet all of its projected growth. MDWASD anticipates that these alternative sources will be available during periods of drought.