Stormwater Department - Robert Haley (615) 848-3200

Paver blocks tested for infiltration at Gateway Village

This video shows how readily a large amount of water soaks into the pavement at Gateway Village on April 19 demonstrating how the not-so-common paver system manages stormwater on site. The paver blocks are separated from each other by a fraction of an inch, enough to allow water to pass between them, and the blocks are set on a bed of gravel about two feet deep, able to store a three-inch rainfall. 90 percent of storms in Murfreesboro result in less than 1.2 inches of rain. The paver technology is one of a number of stormwater management systems called “green,” because they promote infiltration of rainfall into the ground, or re-use or evapotranspiration of rainfall.

Gateway Village is being constructed to meet criteria of the U.S. Green Building Council for energy conservation and environmentally friendly design (LEED). The multi-use property incorporates recycled materials, energy-reducing power systems, re-purified water for landscape watering and flushing, on-site stormwater management, amenities for electric vehicles and bicycling to work.

Codes and Ordinances

City Code Chapter 27½ Storm Water Management - Establishes requirements of major aspects of stormwater program, including Land Disturbance permits and EPSC plans, concept plans, management plans, post-construction runoff quality standards, Water Quality Protection Areas (stream buffers) and stormwater user fees.

Post-construction storm water quality standards

Federal and state stormwater rules require the City of Murfreesboro to implement post-construction runoff standards. As implemented in Murfreesboro, this includes a total suspended solids (TSS) reduction standard, rate and volume control, and administrative mechanisms for ensuring good installation and inspection and maintenance of the controls long-term. Here is a summary of the requirements and a set of forms.

Small-site development options

Do you have a development proposed in the City of Murfreesboro less than two acres of imperviousness (rooftop, paving and sidewalks, for example)? If so, you can meet the City’s post-construction requirements of 80 percent total suspended solids (TSS) removal and Stream Bank Protection requirement by using Low Impact Development (LID) techniques as outlined in the linked technical memorandum.

This memo details certain LID design practices that will allow the site to discharge less than two cubic feet per second (cfs), which qualifies it as a “small site”. If you can provide us the detailed calculations using other LID techniques that demonstrate less than two cfs post-developed runoff and 80 percent TSS removal, then City staff will review your submittal and consider your alternative “small site” option.”

Storm water quality and surface water quality protection

Along with other City departments, part of the mission of the Water and Sewer Department is storm water quality and surface water quality protection.

The city is regulated under State and Federal rules to implement a storm water quality program in six minimum measures and more.

Six minimum measures:

• Public education and outreach on storm water impacts
• Public involvement / participation
• Illicit discharge detection and elimination
• Construction site storm water runoff control
• Post-construction storm water management in areas of new development and redevelopment
• Pollution prevention / good housekeeping for municipal operations

Surface water quality improvement projects:

• TMDL implementation
• Stream restoration
• Stream monitoring. New Post-Construction Storm Water Standards

The City has adopted a standard that new development and redevelopment incorporate stormwater management systems that will capture on site 80 percent of the Total Suspended Solids (TSS) that would otherwise be washed off site in storm events.

Design principles and technical guidance to accomplish these standards and reduce storm water fees:

• Stormwater Controls Manual
• Stormwater Planning and Low Impact Design Guide

See the Design Manuals and Maintenance Plans and Agreements for more information.

Stormwater Videos

• High Stream flow on Armstrong Branch - Robert Haley describes some water quality issues in local streams while observing Armstrong Branch.
• Dye Tracing - A brief video describing what dye tracing is and what it is used for.
• Bushman Creek Macro Invertebrates Collection
• Groundwater Seep on Bushman Creek
• Bushman Creek Erosion
• Probing in Bear Branch - checking the ph, conductivity, and temperature in Bear Branch during a stream assessment.
• Sediment in Bear Branch - Sediment observed in Bear Branch during the MWSD stream assessment of the East Forks Stones River.
• Trash Dumping in Bear Branch - MWSD Stormwater Department Assessment in the upper reach of Bear Branch finds a trash dumping site.
• Permeable Pavers demonstration at Gateway Village - This video was taken by Margaret Ann Ely at a permeable paver demonstration on April 15, 2011, at the Gateway Village mixed use development located at 804 North Thompson Lane in Murfreesboro, Tennessee. Currently this is the largest permeable interlocking concrete pavers (PICP) project in Tennessee at 92,000 square feet. The permeable paver system allows rainwater to filter through the parking lot into an aggregate stone basin that temporarily stores and filters the water runoff. During the demonstration, the Murfreesboro Fire Department release 1,500 gallons of water at 75 psi. You can see from the video that the permeable paver system captured the water on site not creating stormwater runoff. The pressure from the force of the water, which was more forceful than normal rainfall, caused the smaller pebbles located between the pavers to move. These were swept back into place after the demonstration. The Gateway Village is LEED certified project that will also provide car charging stations and other LEED recognized amenities.

Stormwater News

Creating a streamside buffer

A streamside buffer zone is an area along the bank of a stream where plants and trees are growing naturally and to maturity. A buffer provides wildlife habitat and improves the quality of the stream in several ways. One of those is shading and cooling the stream, which reduces unwanted algae growth and renders oxygen more accessible to fish. If you live beside a stream or river, we want you to set aside a buffer for it. Read our brochure on creating a buffer, and if you let us know, we’ll post photographs of your result. Contact us at 848-3200 or by e-mail.

Stream assessments

The Murfreesboro Water and Sewer Department is conducting stream assessments for water quality in the Upper West Fork Stones River Watershed. State and federal regulations require the City of Murfreesboro to take certain measures to maintain good water quality in local streams. In order to comply with these regulations and keep local waterways clean, MWSD began screening streams on foot this past spring. Various techniques will be used to analyze the condition of the Upper West Fork Stones River Watershed including: water sampling, biological diversity screening, and stream bank assessment. Results from this assessment will help to improve any impairment that the streams may have and maintain good watershed condition. See field videos of stream assessments, make sure to click on See All for all stormwater videos.

Stormwater Map Now Available

MWSD Stormwater - current information about stormwater and BMPS.

Stormwater user fee questions?

Please watch this presentation that was presented to the Murfreesboro City Council that goes over the history of the City’s stormwater permit, how the stormwater user fee was derived and how the revenue will be used for stormwater management inside the city limits of Murfreesboro.

Storm drain labeling

The City is soliciting volunteer groups – for example, schools, scouts, churches, neighborhood groups, adopt-a-stream groups – to perform labeling of storm drains with an environmental message; “Don’t Dump – Drains to River”. The City supplies the materials for labeling. Labels inform passers-by that storm drains lead directly to the river or local creek.

Storm water areas to be cleared of sediment

Stormwater lines are scheduled to be cleared of trash and sediment within the next few weeks in the Lytle Creek and Town Creek basins. The cleaning will be performed by a jet vac truck. Cleaning the lines will prevent sediment from reaching the water, allowing the water to flow more easily into local streams, and help prevent future flooding problems.

2011-12 Annual Stormwater Quality Report