"April showers bring May flowers" brings to mind gentle rains and the good things that ensue: gardens, flowers, and green grass. It's not often that the thoughts go to stormwater and the environmental impacts of those April rains. As hard surfaces have increased so have the issues of managing water that has no place to go except directly into streams and rivers often carrying pollutants. Our topic this month is about stormwater management and the many ways it can be a positive rather than a negative. Planting trees, collecting rain in a barrel, and increasing pervious surfaces are some of the ways we as individuals can help. So enjoy our stories and happy spring! -Lori |
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 | | Vegetation slows down and filters stormwater run-off on Deaderick Street. |
Nashville's Deaderick Street Project - A Sustainable Complete Street In fall of 2009, Deaderick Street became Nashville's first application of a "green street". The completed sustainable design used low impact development (LID) and green methods to help secure two awards in 2010, the 'Project of the Year' and the 'Honor Award' given by Tennessee Chapters of the American Society of Civil Engineers and by the American Society of Landscape Architects, respectively. That same year, Mayor Dean signed Executive Order No. 40 formalizing Nashville's Complete Streets Policy. Prior to project implementation, the street housed sheltered stations used for dispatching Metro's bus transportation network. Located in the Kerrigan Basin, the street historically experienced overflow of its combined storm sewer during some rain events. Following the bus operation relocation, the Mayor's office looked to make substantial improvements to rectify the stormwater issue and re-envision an attractive and prominent Deaderick Street that connects the two houses of City and State government: the Mayor's office and the Governor's office. The project consisted of many sustainable features including: - 700% increase in pervious area helps divert approximately 1.2 million gallons of stormwater per year
- Bio-swales at sidewalk and street level to capture, filter, and infiltrate rainwater
- Porous concrete in sidewalk
- 102 shade trees that helps reduce temperature of surrounding areas by 35% and 4,249 shrubs
- Irrigation utilizes low flow nozzles using 33% less water and drip system
- LED - Pedestrian streetlights, pedestrian way finding kiosks, traffic signals
- Solar-powered parking meters
- Recycling disposal units for convenient on street recycling collection
- Sub-base of concrete walls made of recycled concrete
- High percent recycled content in light poles, tree grates, fence, trash/recycling containers, and way finding kiosks
- Recycled coal fly ash within concrete
- Local steel fabricators used
Complete Street policy and background. Other complete streets are Shelby Avenue in East Nashville, Belmont Boulevard and Otter Creek. In Nashville, Complete Streets vary in design, but will likely include measures like bike, pedestrian, vehicle, and transit facilities that promote sustainability and complements the area. |
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This graphic shows the path of stormwater from beginning to ending. |
Struggles With Stormwater
A municipal separate storm sewer system (MS4) is defined as a system of publicly-owned conveyances, including roads, curbs, gutters, swales or ditches that discharge to surface waters of the state. MS4 systems are designed or used solely for collecting or conveying stormwater. This stormwater is not routed to a wastewater treatment facility; it is directly discharged into local bodies of water.The term MS4 does not solely refer to publicly-owned storm sewer systems. Rather the term has a much broader application that can include, in addition to local jurisdictions, state departments of transportation, universities, local sewer districts, hospitals, military bases, and prisons. Currently, there are five Phase 1 MS4s located in Tennessee: Knoxville, Nashville, Memphis, Chattanooga and the Tennessee Department of Transportation.
How can an MS4 impact drinking water quality? In Tennessee, people get their water from streams, rivers, lakes and from groundwater. Impervious surfaces, such as streets, sidewalks and parking lots cannot easily absorb water. When a pollutant is spilled on an impervious surface, it will remain until stormwater runoff washes it away. When it rains or snows, the water that runs off of land surfaces can force sediment, oil, grease, toxins, pathogens and other pollutants into nearby water bodies. The pollutants associated with stormwater runoff can adversely affect the physical and biological health of Tennessee's surface waters. These pollutants can reduce the recreational use of Tennessee's waters and be detrimental to the habitat and diversity of aquatic organisms, fish and other wildlife. Pollutants in our water cause water treatment to be more costly and can be bad for our health.
We, as Tennesseans, can help reduce the level of pollutants by following some of these best management practices.
- Don't dump ANYTHING down storm drains. Oils, chemicals, soaps, etc. pollute our streams and lakes.
- Use pesticides and fertilizers sparingly and always follow label instructions.
- Put litter in its place (trash cans or recycling bins).
- Pick up after your pet.
- Sweep driveways (don't spray wash) and dispose of the sweepings properly.
- Collect yard waste and keep it out of storm drains. Compost! Even grass clippings and excess leaves don't belong in our streams and rivers.
- Use a commercial car wash (they treat and recycle wash water) or wash vehicles on grassy areas.
- Recycle used motor oil. Most auto parts retailers accept used motor oil for recycling.
- Check your car for leaks (and fix them).
- Have your septic tank inspected every 3 - 5 years by local septic tank companies to insure proper operation.
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Artist conception of the demonstration park. |
Harrell Road Stormwater Demonstration Park
Stormwater management is a hot topic in today's world. Clean, potable water is becoming more of an issue as the population of the Earth increases. One thing that can be done to protect our drinking water is to handle stormwater properly. Stormwater pollution has become an issue due to primarily the increase in impervious surfaces. Knox County is addressing the problem with an innovative approach. They have created a stormwater remediation park. This park is a learning laboratory for those who want to learn about stormwater management. Through educational measures, they hope to educate future generations on environmentally sound practices for managing stormwater.
This park was built on 15 acres of unbuildable land that was donated to the Legacy Parks Foundation. Once completed, Legacy Parks will donate the park to Knox County. Partial funding for the project came from a grant ($95,400) from the Tennessee Healthy Watershed Initiative. This project has been featured in the local media to bring awareness to the public. The site has a pond, access to Beaver Creek, low-lying wetland areas, and approximately 4,000 feet of trails and boardwalks. The trails and boardwalks surface are constructed using a pervious material and there is interpretative signage about the project. The park will also provide valuable habitat for a variety of wildlife. Some of these habitats are man-made while some are natural. As water enters the site, it is slowed by check dams which give the planted rain gardens an opportunity to filter out sediment, nutrients, metals, and other undesirables.
Wetlands were also constructed to allow the water to be held for a longer period of time. This allows for further filtration of the stormwater, provides the aforementioned wildlife habitat, and helps to recharge aquifers in time of drought conditions. This park is the first of its kind in the area and acts as a living laboratory for all to enjoy. |
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