Green Infrastructure Digest

Interpretive signs for an upcoming project near the Harpeth River in Williamson County will highlight the ecological significance of the waters of the southeastern United States. If you didn’t know, the rivers and streams of middle Tennessee are part of the most unique and diverse freshwater ecosystem in the entire world. This has to do with a couple things, namely the temperate climate combined with the fact that much of the area was unglaciated, or it as been more geologically stable than other parts of the U.S.

Just to give you an idea the area is home to more than 250 species of crayfish (70% of all the species in the entire U.S.), more than 300 species of mussels (over 1/3 of these live in Tennessee), and more than half the freshwater fish species in the U.S. Because of this great diversity, Tennessee has more freshwater fish that are at-risk than any other state. These species are at-risk largely due to pressures from development practices, which allow sediments and pollutants to wash into our rivers and streams. This and other topics concerning protection of critical watersheds can be found in, Rivers of Life or States of the Union: Ranking America’s Biodiversity, just some of the publications found on the NatureServe’s website.

Graphic from 'Rivers of Life', published by NatureServe

As mentioned in an earlier post, the implementation of ‘green street’ practices on Deaderick Street in downtown Nashville will divert approximately 1.2 million gallons of stormwater a year from the Cumberland River. This is water that would have otherwise run unabated into the river carrying all of the pollutants and sediments from the street. Understanding the significance of the region’s biodiversity is a good reminder of what we are trying to protect when implementing green infrastructure planning and strategies –and why this is especially important here in the Southeast and Middle Tennessee.

-Sara Putney