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Water Quality Issues, Fees and Management Options

Mr. L Sizemore and Dr. W. AndersonMiddle Tennessee State University for

the Mid-State Iris AssociationJune 3, 2008

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Why a Storm Water Fee?

City of Murfreesboro

July, 2007

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Why a storm water user fee?

• EPA

• Maintain and replace infrastructure

• Improve stream water quality

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State and EPA requirements

• Murfreesboro

• Designated urban area

• EPA requires

• MS4 program

• Ensure water quality in local bodies of water

• Requires milestones to met-need equipment, training, staffing

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Maintain & replace infrastructure

• Infrastructure

• In place some time

• Pipers clog

• Impede storm water flow

• Open ditches gradually fill

• Vacuum and water jet trucks

• Replace with BMP

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Improve stream water quality

• Murfreesboro streams impaired• Streams may not be suitable for certain

aquatic life/human recreation• Monitoring/research useful-aid in stream

quality• BMP

Bio retention area, debris catchments, bank restoration

• Improve water quality

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Public outreach & education

• Public out reach

• Ensure water quality

• School education program

• Workshops

• Low impact development

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BMP improvement

• Restoration

• Habitat

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What is an impervious surface?

• Rainwater cannot infiltrate

• More water volume-runoff into storm drain

• Storm water fee

• Median impervious area of single family residential [SFU] propertied-3,470 sq ft

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What is an impervious surface?

• Review of 20,000 + properties

• $3.25 per month

• Commercial property- how many equivalent SFUs

• Commercial – 34,700 sq ft = 10* $3.25= $32.50

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How fee billed?

• SFU-added to bill

• Apartment-bill property owner

• Commercial- bill property owner

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What is goal of storm water fee?

• Maintain water quality

• Allow city to comply – federal-state regulations-unfunded mandate

• Flood damage reduction/drainage

• Long term maintenance

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What is goal of storm water fee?

• Protect water supply

• Stream restoration

• BMP-road construction

• Education for schools

• Workshops for better water quality

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What can you do for clean water?

• Conserve water

• Keep grass clipping out of stream

• Keep restaurant and business waste away from rain

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What can you do for clean water?

• Use min herbicides/fertilizers & keep off paved surfaces

• Pick up pet waste

• Report water pollution

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More information

• And other slide shows

• http://www.murfreesboro.gov/government/water_sewer/stormwater.htm

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What really goes down there?

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Rain Garden Rain Water Management OptionAt Middle Tennessee State

University

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History

• This power point is the result of work completed by MTSU students in ABAS 3370 and 4370 at MTSU. Mr. L. Sizemore and Dr. W. Anderson have worked with MTSU students since Fall 2005.

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What is currently used to manage rain water at MTSU?

•Gutters for roof runoff •Surface drainage ditches and an underground drainage system.•Ditches or tiles direct water to a central basin next to Rutherford Blvd.

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What are some of the problems caused by these methods?

•Petrochemicals and metals are washed off with storm runoff water.

•Rain water and runoff water can dissolve the limestone bedrock.

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MTSU Campus Map

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Blowup of MTSU campus map and drainage ditch (blue)

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Location of Rain Gardens One, Two and Three

• Rain Garden One (2005) is near the MTSU campus greenhouse (GH)

• Rain Garden Two (2006) is near the Horticulture Center (HC)

• Rain Garden Three was completed in Fall 2007 in drainage ditch.

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Surface Drain system being retrofitted with Rain Gardens (RG)

Greenhouse

Commons-underground drain line

Basin

RG 1&2

RG3

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Runoff from curb cut into Rain Garden Three (lot # 66)

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Surface drainage ditch on campus parking lot #66

• The photo looks North toward the campus greenhouse and Rain Gardens One and Two.

• Rain Garden Three (F-2007) has been constructed in drainage ditch

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Alternative ways of dealing with runoff?

• Direct water to a naturalized setting.

• Minimize runoff of average rain by 90%, allowing rain garden (plants and soil)

• Filter pollutants-sediments, dissolved ions- before percolates into groundwater.

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What is a decentralized runoff management system?

• Runoff water directed into rain gardens• Plant canopy and soil can store excess

water.• Rain Garden, shallow basin allows runoff

water to percolate through the soil and transpire through the plants.

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How does a decentralized system work?

Two ways:

1) Plant canopy (trees, shrubs, un-mowed grasses)

A) increase evapo-transpiration

B) reduce water percolation.

2) Rain garden soil is a sponge for

runoff water

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MTSU Agribusiness and Agriscience (ABAS) courses-time line

•ABAS 3370: Soil Analysis class began Rain Garden One the Fall 2005.

•ABAS 4370: Soil & Water Conservation class completed Rain Garden One the Spring 2006.

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MTSU Agribusiness and Agriscience (ABAS) courses-time frame

•ABAS 3370 class began and finished Rain Garden Two the Fall 2006

•Rain gardens One & Two collect runoff from gravel parking lots West and North of the Horticulture Center

•Runoff water contains lime dust

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Decentralizing the pre-existing drainage system at MTSU

•ABAS 3370 in Fall 2007 built Rain Garden Three in the drainage ditch• Planted in F 2007 and Sp 2008•Horticultural Center to the drainage basin by

Rutherford Blvd (approximately ½ mile).

•Additional Gardens will be built in drainage ditch

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Surface Drain system being retrofitted with Rain Gardens (RG)

Greenhouse

Commons-underground drain line

Basin

RG 1&2

RG3

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Looking North toward Rain Garden One

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Before Rain Garden One, Fall 2005

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Survey in Rain Garden one (Fall 05)

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Checking land elevation after excavation F 2005

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Digging out Rain Garden One (F 05)

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Rain Garden One excavation completed in October 2005

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Water in excavated Rain Garden One-spoil piles in trees Sp 2006

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Spoil piles in background-gravel at entrance Rain Garden One-Sp 06

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Water in excavated area for Rain Garden One Feb 06

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Rain Garden One, Water filled after a rain storm Feb 06

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Mar 06 adding and leveling prepared mix to Rain Garden One

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Mar 06 leveling pooling area of Rain Garden One

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Completing initial work on berm for Rain Garden One (Sp 06)

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Rain Garden One, Spring 2006

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Rain Garden One

• Deeper and longer than needed in a residential landscape

• Why?

• It had to fit in an existing drainage ditch surrounded by parking lots.

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How to Plan a Rain Garden

• Garden is down slope from the area it is draining.

• Small rain gardens are easier to maintain than one large rain garden.

• Garden should be greater than 10 feet from building foundation.

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Building Rain Garden Two: Placement

• Rain Garden Two is on the East side of Horticulture Center.

• Captures water from the graveled lot on the West side of the Horticulture Center.

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Other Placement Considerations

• Do not place over a septic system or where water pools more than 5 days.

• The garden soil should drain well.

• How a soil drains can be determined by watching the site after a rainfall event Does it drain within 2 to 3 day If not infiltration and percolation rate can be estimated.

• Clay soil or compacted soil can be amended to improve infiltration and percolation.

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What is water infiltration?

• How quickly does water move into a soil?

• Watch a possible area after a rain fall event.

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What is the percolation rate?

• The percolation rate is the time it takes for one inch of water to pass through a soil.

• The ABAS class used these perc rates:<60 minutes/inch60-75 minutes/inch>75 minutes/inch

• A good rate for a rain garden is <60 minutes per inch.

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How to determine percolation rate by soil

texture?

• Using a post hole digger, dug holes 6 to 8 inches for a shallow basin or 24 to 36 inches for a deep basin.

• For faster than 60 minutes per inch Excavate soil has a medium or fine textures

subsoil Or fine reddish textured subsoil

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How to determine percolation rate by soil texture? (continued)

• For 60 to 75 minutes per hour Excavated soil is reddish fine textured subsoil

to at least 24 inches and yellow clay between 24 to 36

• For slower than 75 minutes per inch Excavate soil with bed rock within 36 inches or soil having a yellowish, grayish, or blackish

fine textured subsoil

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Texture by feel flow chart

• http://soils.usda.gov/education/resources/k12/lessons/texture/

• Fine texture soils: Sandy clay, Silty clay and clay

• Medium texture soils: silt loam, loam, sandy clay loam, clay loam, silty clay loam

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Rain Garden 0ne –before mixing sand

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Spreading sand in Rain Garden One

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Spreading sand before tilling

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Because Rain Garden One was large –tiller used

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Rain Garden One-one pass with tiller after spreading sand

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Rain Garden One- tilling in sand

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Rain Garden One –tilling and shovel work

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Rain Garden One-mixing in sand

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Building Rain Garden Two: The Percolation Rate

• Dug holes to 24 inches, excavated soil in the proposed Rain Garden, was medium textured.

• 1” gravel in bottom, filled holes with 6” of water and record time to drop one inch. Stuck a tooth pick in the side of the hole for measuring water drop.

• Measured, 15 minutes per ¼” water drop, or 60 minutes per 1” water.

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Building Rain Garden Two:Sizing?

• The size of the rain garden can be calculated. Residential size: 100 to 300 sq ft

• The size required to capture surface runoff around the HC was determined by Mr. Sizemore’s observations. Dimensions: 8 feet x 24 feet by 6 inches deep

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Finding the Area Rain Garden

• If rain garden catch water from a rain spout, use that part of the roof area.

• Lawns, graveled or paved driveways, additional runoff water for a rain garden.

• The area to be drained can be multiplied by a size factor to determine area of rain garden.

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Size factors are determined according to the type of soil and the depth of the garden and differ if the garden is

<30’ or >30’ from a building

<30Feet

3-5” deep

6-7” deep

8” deep

Sandy Soil

0.19 0.15 0.08

Silty Soil

0.34 0.25 0.16

Clayey Soil

0.43 0.32 0.20

>30 feet For all depths

Sandy Soil 0.03

Silty Soil 0.06

Clayey Soil 0.10

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% Slope Relates to the Depth of the Rain Garden

• For slopes <4%, the garden depth should be 3-5 inches deep.

• Between 5-7%: 6 to 7 inches deep

• Between 8-12%: about 8 inches deep

• For slopes over 12%, a rain garden will take a great deal of fill, another location should be considered.

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Calculating the Slope & Area of the Rain Garden

• Drive two stakes about fifteen feet from each other (one uphill, one downhill).

• Tie a string level to each stake and adjust it to make it level.

• Measure height difference between the ground and the string in feet, divide difference by the distance between the two stakes.

• Multiply by 100 to get the percent slope.

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Defining the Shape of the Rain Garden

• Shape should be aesthetic.

• Recommend, length of the garden be perpendicular to the slope, will catch as much water as possible.

• Garden should be twice as long as it is wide.

• Width should be no more than 10-15 feet.

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Building MTSU Rain Garden Two: Digging

• Mark the perimeter of the garden.

• Front end loader was initially used; for residential garden use a garden tiller .

• District conservationist (NRCS) showed the class how to measure slope with a laser level. It is easy to do with a string and line level.

• The inlet was higher than the outlet and the bottom of the garden was leveled.

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Digging a Rain Garden

• Hammered stakes around the perimeter and ran string level between stakes across the middle of the garden.

• Dig the bed level at the desired depth with rakes and shovels.

• Use the removed soil to build a berm on the downhill edge of the garden.

• Covered channel above and below inlet and outlet with landscape fabric and gravel

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Building Rain Garden Two:Planting

• The 2006 Soil Analysis class planted native bushes and perennials.

• The arrangement was done in a naturalistic fashion using odd number groups.

• Odd number groups ease future maintenance of the Rain Garden.

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Planting a Rain Garden

• Rain garden plants should be tolerant of moist and dry conditions.

• Commercial landscape plants can be used but consider native plants.

• Plant density should be higher and more naturalistic looking than commercial type plantings.

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Spreading Mulch in Rain Garden Two, Fall 2006

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Building Rain Garden Two: Mulch and Rock

• Placed landscape fabric at the entrance of the Rain Garden.

• Covered the bottom of the Rain Garden with double-shredded mulch to the desired depth.

• Covered the landscape fabric at the entrance with river rock.

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Rain Garden Two, Finished Product, Fall 2006

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Looking South from Rain Garden One toward Rain Garden 3 before its

Excavation in Fall 2007

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Rain Garden Three Specs

• Infiltration Rate 3 inches in 90 minutes

• Depth 7 inches

• Materials Used river rock, landscape fabric, recycled concrete

(from construction site on campus), native plants.

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Plants Used

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• River Oats - Chasmanthium latifolium

• Swamp Milkweed – Ascelpias incrnata

• Red Twig Dogwood - Cornus sericea

• False Sunflower – Heliopsis helianthoides

• Helberd Leaf Rose Mallow – Hibiscus laevis

• Inkberry Holly – Ilex glabra

• Winterberry Holly – Ilex verticillata

• Big Blue Lobelia – Lobelia siphilitica

• Common Rush - Juncus effusus

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Construction of Rain Garden Three During Excavation

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Construction of Rain Garden Three after Excavation

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The only outlet for parking lot 66. The dark soil is a result of oil and other pollutants

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Rain Garden Three: Excavation

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Notice the normal red clay

Notice oil polluted clay

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Dr. Anderson Points out Contaminated soil

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River Rock

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Spreading River Rock-covering landscape fabric

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Landscape Fabric

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Although fabric is beneficial to prevent weeds, it does not allow the rock to settle. Notice how the fabric and rock washed away due to heavy rain.

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Landscape Fabric Correction

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We corrected the problem with recycled concrete and rocks to hold the fabric in place and to slow down the water flow.

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Rain Garden Three; Completed, F 2007-lime dust on river rock

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In Summary

• Environmental problems caused by surface drainage in developed areas can be reduced by changing landscape practices.

• Limit mowed lawn space and raise mower blade to increases plant canopy.

• Stacked Rain gardens in the landscape allow excess water to infiltrate the soil in many places before water flows to lowest elevation.

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Plant Lists

• Plant lists will be available on request from:

• 1. your local extension office

• 2. Tennessee Master Gardeners

• 3. web search: rain garden plants

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Rain Garden One –Su 2008-looking South

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Rain Garden One-Su 2008

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Berm at end of Rain Garden One-Rain Garden Two to right

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Rain Garden One looking North-Su 2008

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Entrance to Rain Garden One on North Side looking East-Su 2008

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Rain Garden Two-su 2008

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Rain Garden Three looking South- Su 2008

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Rain Garden Three looking South-Su 2008

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References

• 1.) http://clean-water.uwex.edu/pubs/raingarden/• 2.) http://raingarden.il.gov/create.htm• 3.) Prince George County Bioretention Manual• 4.) Rain Gardens- solving drainage problems, Tennessee Gardener,

• August 2005• 5.) Land Judging Guide, UTK, PB 727• 6.) www.cleanwaterccampaign.com/what_can_I_do/raingarden.html• 7.) Estimating Soil Texture, GardenNotes #214, • www.cmg.colostste.edu• 8.) Guide to Texture by Feel, • http://soils.usda.gov/education/resources/k_12/lessons/texture/• Rev 3-10-07, 3-15-07, 4-4-07,June 3, 2008

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Fact sheet- Rain Garden Design

• http://www.lowimpactdevelopment.org/raingarden_design/links/htm

• http://www.dof.virginia.gov/rfb/rain-gardens.shtml• http://www.utk.edu• Construction• Cost Cost of Not• What is a Rain Garden? • Man-made depression; Improve water quality• Bioretention area: 1.) Collect water runoff, 2.) Store it, 3.)

Filtered slowly-Nutrient removal• How? Contact with soil and plant roots

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Fact sheet- Rain Garden Design(2)

• Who Should Create a Rain Garden?• Suitable any land use; Residential, commercial, industrial• Place so impervious surfaces drain into depression• Grass buffer strip• Slows water entering rain garden; Surface filters

particulates from runoff• Pond area• Depression area, stores water; Evaporation; Particulate

not filtered to settle to bottom; • 6 inch depth; Not pond more than 3-4 days – avoid

mosquito breeding

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Fact sheet- Rain Garden Design(3)

• Who Should Create a Rain Garden?• Suitable any land use; Residential, commercial, industrial• Place so impervious surfaces drain into depression• Grass buffer strip• Slows water entering rain garden; Surface filters

particulates from runoff• Pond area• Depression area, stores water; Evaporation; Particulate

not filtered to settle to bottom; • 6 inch depth; Not pond more than 3-4 days – avoid

mosquito breeding

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Fact sheet- Rain Garden Design(4)

• Components of a rain garden• Mulch/Organic Layer• Decomposed organic material; Removes metals; Shredded

hardwood mulch• Planting Soil• Leaf mulch (20%), sandy soil (50%) and 30% top soil; Clay particles

adsorb• Planting Selection • Species that tolerate extremes, perennials• Site Considerations• Site: Intercept water runoff• Bioretention area: 5 to 7% of drainage area (example ¼ roof area)

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Fact sheet- Rain Garden Design(5)

• How to Design a Rain Garden?• Tennessee – Murfreesboro Water and Sewer Department• http://www.murfreesborotn.gov/government/water_sewer/stromwater

/residents.html• Harpeth River Rain Gardens for Backyards• http://www.harpethriver.org/backyard_raingardens.html• Maintenance: Dry, Spring• Plant Lists http://www.tneppc.org• Local nurseries of Tennessee Nurseryman’s Association• Questions: Rutherford County Extension office: 898-7710• Brown bag lecture, 4th Thursday of each month June 21 from 11:30-

12:30, 315 John Rice Blvd