Updates from the New Jersey Water Supply Authority Watershed Protection Programs Division: information about our River Friendly Programs, field work, current and upcoming projects, and some random thoughts.
A few months ago, we were contacted by Raritan Valley Habitat for Humanity about rain barrels. They are building nine houses in Bridgewater, close to the Raritan River, and they were interested in rain barrels. The NJ Water Supply Authority purchased rain barrels, automatic downspout diverters, and soaker hoses to outfit each house with two rain barrels to conserve water and reduce stormwater runoff. The Habitat staff learned how to build the barrels, and built 18 inch high stands for the rain barrels. Habitat staff and volunteers put the rain barrels together and so far, have installed 9 barrels.
This setup is different than the typical setup we have promoted in the past, and from what is in our rain barrel brochure. The automatic diverter eliminates the need for a separate inflow and outflow, as well as the need to reconfigure the downspout each winter. The diverter can stay on your downspout, as it is metal rather than plastic, and only the plastic tubing needs to be removed and the holes plugged up. The barrel should still be drained in late fall.
The setup takes a little more time than just cutting the downspout and adding a flexible downspout attachment, plus an overflow hose to the top of the barrel. In this setup, when the barrel is full, it backs up water in the flexible green hose, which sends the rain water down the regular downspout, which may drain to your yard (we hope), driveway, or the street.
How the automatic diverter works
If you are interested in installing a rain barrel on your house, you should check into an automatic diverter system. Be aware of the material of the diverter (plastic vs. metal) and fully understand the installation before purchasing. Also realize that a diverter system may affect the construction design of the rain barrel itself. These barrels do not have an open top (they are screw off for cleaning) and do not require a mosquito screen.
Yesterday, I had the fortunate opportunity to attend a presentation at the Edison EPA office and to tour their stormwater best management practices (BMPs). I was especially intrigued by their permeable pavement parking lot. They are testing the three types of permeable pavement out there: pervious concrete, porous asphalt, and porous pavers.
Now, why are these important, and what makes them a best management practice? Traditional pavement--asphalt and concrete, what makes up roads, sidewalks, parking lots, etc--is impermeable, meaning that water is not able to pass through. Natural spaces, like forests, have pervious grounds surfaces, which means that water does pass through the soil, replenishing the groundwater supply. As development occurs, heavy machinery runs over our native soil (which may have been pervious in the past), which compacts the soil, making it impervious.
Modern stormwater practices carry water away from these impervious areas (storm drains, detention basins, etc) and do not allow water to enter the soil below, which also acts as a filter for pollutants, like sediment and motor oil. In short, permeable pavement allows water to pass through and eliminates some stormwater (and pollutants) from reaching our streams. Some flooding is caused by excess stormwater from development, which historically had been held on site and infiltrated into the ground.
So at EPA, they have a demonstration parking lot, where they are testing out these permeable pavement options. This is an active office parking lot, and they have hundreds of instruments under the parking lot to be able to measure the effectiveness of the pavement options.
The three options
porous pavers
porous asphalt
pervious concrete
Each has their challenges, but they all have big benefits. Just take a look at how effective these pavement options can be:
For more information about the project, here's the video from EPA, or visit their website.