A regional compact among four Southeast Florida counties allows for ample sharing of resources to tackle shared problems
The Miami-Dade Water and Sewer Department always has its eyes on the future and what it has to do in the present to protect and improve the resiliency of its assets. Climate change of course factors into that picture of the future. But the utility hasn’t had to worry about tackling the problem alone. It has the help of neighbors across three other counties.
The Southeast Florida Regional Climate Change Compact was formed in 2010, made up of the four-county region of Miami-Dade, Broward, Monroe and Palm Beach. The rationale? Climate issues are regional and can have far-reaching social and economic consequences, and more resources can be focused on problem-solving when municipalities work together.
“The compact provides tangible benefits to county and city services,” says Nichole Hefty, deputy resilience officer for Miami-Dade County. “We are able to leverage each other’s resources, develop regional climate action plans, and identify best management practices, using expertise from a range of sources — universities, the Army Corps of Engineers, the South Florida Water Management District, and agencies like the National Oceanic and Atmospheric Administration and the United States Geological Survey.”
Much of the compact’s data gathering efforts focus on sea level rise, temperature trends, and changes in precipitation, all of which can have a serious impact on the region’s water and sewer infrastructure.
“Sea level rise rates may vary from country to country, but not across county lines,” Hefty says, noting that the compact has been able to pull together resources and look at sea level rise data specifically for Southeast Florida. The coastal area is heavily populated and especially vulnerable to rises above high tide levels in the next few decades.
In addition, the region is underlain by porous geology and shallow drinking water aquifers. The increased frequency and intensity of rain events can result in more frequent and extreme flooding events, as well as potential contamination from flooding and stormwater overflows. As sea level continues to rise, the groundwater will rise closer to the surface, further reducing the capacity to accommodate stormwater.
According to a report by the compact, sea level rise is projected to be 6 to 10 inches by 2030 and 14 to 26 inches by 2060 (above the 1992 mean sea level). In the long term, sea level rise is projected to be 31 to 61 inches by 2100.
“The National Aeronautics and Space Administration Jet Propulsion Laboratory (2015) has reported the average global sea level has risen almost 3 inches between 1992 and 2015, based on satellite measurements,” the report states. “Sea level rise in South Florida has been of similar magnitude over the same period (NOAA, 2015) but is anticipated to outpace the global average due to ongoing variations in the Florida Current and Gulf Stream.”
The delicate balance between seawater and groundwater is also threatened as the rise of sea level and the resulting increase in hydraulic pressure pushes the salt front farther inland, putting the freshwater aquifer and drinking water wells at risk of contamination.
“The resources and documents we’re developing are being used by municipalities in their planning,” Hefty says.
In the case of the Miami-Dade Water and Sewer Department, consultants designing infrastructure improvements are required to use the sea level rise projection for Southeast Florida developed by the compact to determine the design criteria appropriate to protect assets from sea level rise, based on the lifespan of a particular asset and the criticality of a particular piece of infrastructure.
Read more about what the Miami-Dade Water and Sewer Department is doing to improve its systems in this full profile featured in the June issue of Municipal Sewer & Water magazine.