How Land Planners, Engineers, and Water Resource...

How Land Planners, Engineers, and Water Resource Professionals can work together for multiple benefits

Todd Wood, P.E.DTWood Engineering, Inc.

412 Shade Tree Way, Johnson City, TN 37604423-791-4730

Current Tennessee Stormwater Management• Permanent stormwater management

required

• Currently peak flood control using pond(s)

• Channel protection using extended detention pond

• Water quality using 80% TSS removal

• Runoff rate focus

• Cubic feet per second

• Does very little to reduce volume runoff

Proposed Tennessee Stormwater Management• Direction is Runoff Reduction

• Flow rate control

• Volume control

• Spring 2015 Deadline

• TDEC currently working on State-wide Manual

• Green infrastructure

Green Infrastructure• TN MS4 Permit, Section 4.2.5.2.1 Runoff

Reduction:

Site design standards for all new and redevelopment require, in combination or alone, management measures that are designed, built and maintained to infiltrate, evapotranspire, harvest and/or use, at a minimum, the first inch of every rainfall event preceded by 72 hours of no measurable precipitation. This first inch of rainfall must be 100% managed with no stormwater runoff being discharged to surface waters.

Green Infrastructure• Per EPA

• refers to natural systems that capture, cleanse and reduce stormwater runoff using plants, soils and microbes.

Green Infrastructure• Per EPA

• Site scale

• site-specific management practices including preserving open space

• maintain natural hydrologic functions by absorbing and infiltrating precipitation where it falls.

Green Infrastructure• Per EPA

• City, county, regional scale

• interconnected network of open spaces and natural areas such as forested areas, floodplains and wetlands.

• improve water quality while providing recreational opportunities, wildlife habitat, air quality and urban heat island benefits, and other community benefits.

Open Space• Major component of green infrastructure

• Preservation always better than creation

• Creation better than structural practice

• Soils are the key

• Healthy native soils are best

• Absorb and infiltrate stormwater

• Plant growth

• Filtering stormwater with soil and vegetation is more effective than non-soil based BMPs

Open Space Defined(APA Planners Dictionary)

• Numerous definitions

• Many include the non-buildable areas and/or areas to remain undisturbed or undeveloped state

• Areas that remain un-built and shall not be used for parking, storage, or display (Maynard, Mass.)

• Land and water areas retained for use as active or passive recreation areas or for resource protection in an essentially undeveloped state. (Cecil County, MD)

• … to protect water, air, and plant areas. (Clarksdale, Ariz.)

Kingsport, TN Open Space• Open space

• means the outdoor area of a lot or tract which is designed and used for outdoor living, recreation, pedestrian access or landscaping

• Usable open space

• means the outdoor area of a lot or tract which is designed and used for outdoor living, recreation, pedestrian access or landscaping.

Drainage/Storm Drain System Defined(APA Planners Dictionary)

• Numerous definitions

• A system of man-made structures designed to collect, convey, hold, divert, or discharge storm water. (Polk County, Fla)

• One or more artificial ditches, tile drains, or similar devices which collect surface runoff or groundwater and convey it to a point of discharge (Milwaukee, Wisc.)

• The system of inlets, conduits, channels, dikes, and other appurtenances which serve to collect and convey stormwater. (Concord, NC)

Green Space Defined• An open space available for unstructured recreation, its

landscaping consisting of grassy areas and trees. (APA, Austin, TX)

• a plot of undeveloped land separating or surrounding areas of intensive residential or industrial use that is maintained for recreational enjoyment (dictionary.com)

What’s the Point?• Open space and natural areas not considered

stormwater conveyances or management areas

• Consider modify or creating open space and/or green space definitions which include use for stormwater management

• Consider modifying or creating stormwater or storm drain definitions which include open space or green space as potential stormwater conveyances and/or management areas

• We need to think of our natural/open space areas as more than just a pretty place-they are the original storm drain systems

Hydrologic Cycle

Hydrologic Cycle

Per Guidelines and Resources For Implementing Soil Quality and Depth BMP T5.13 in WDOE Stormwater Management Manual for Western Washington. Washington State Dept. of Ecology

Hydrologic Cycle

Per Guidelines and Resources For Implementing Soil Quality and Depth BMP T5.13 in WDOE Stormwater Management Manual for Western Washington. Washington State Dept. of Ecology

Green/Open Space for Stormwater Management• Stormwater professionals look at green

space differently than other professionals

• Conveyance system (horizontal)

• Infiltration system (downward )

• Evapotranspiration system (upward )

• Filtering system (TSS and pollutant removal)

• Cooling system (thermal pollution)

Green/Open Space for Stormwater Management• Any area available for preservation

of natural resources such as grass, trees, and/or water

• Any area for creation or restoration of new pervious surfaces stabilized with grass, trees, and/or other vegetation

• Any area where a plant/soil BMP can be constructed

Go Vertical!

• The more stormwater can travel in the vertical plane the better

• Evapotranspiration

• Infiltration

Stormwater Open Space

Stormwater Open Space

Stormwater Open Space

Stormwater Open Space

Stormwater Open Space

Stormwater Open Space

Stormwater Open Space

Stormwater Open Space

Stormwater Open Space

Why Protect Water Quality?• Recreation

• Swimming, kayaking, wading, etc.

• Fishing

• Human and animal health

• Biodiversity

• Economics

• Drinking water

Drinking Water• 96% undrinkable, 2% polar ice

• Only 2% for drinking, agriculture, plant growth

• Water scarcity is already a problem in areas

• Regional droughts

• Water table lowering, wells drying up

• Polluted waters

• “water shortages are increasingly becoming a serious concern worldwide”-Eco-Link, Forests and Water Quality, Volume 19, No. 1)

New York, NY• Over 8 million people

• Drinking supply

• Reservoirs and lakes

• 75% of 2000 sq mile watershed forested

• Forests protected with public-private agreements

• Using forests to filter and feed water supply

• Without this, costly water treatment facilities would have to be built

(Eco-Link, Forests and Water Quality, Volume 19, No. 1)

Boston, MA• 2.2 million people

• Drinking supply

• Reservoirs and river

• 100,000 acres forested

• Forests protected due to location on public lands

• Periodic harvesting for long term forest sustainability

• Using forests to filter and feed water supply

• Without this, costly water treatment facilities would have to be built

(Eco-Link, Forests and Water Quality, Volume 19, No. 1)

Raleigh, NC• 420,000 people

• Not enough water by 2050

• Drinking supply

• Reservoirs and lake

• 100,000 acres forested

• Forests protected within watershed

• Sustainable forest practices and education

• 4:1 return on investment

• Avoided having to build costly treatment facility

(Eco-Link, Forests and Water Quality, Volume 19, No. 1)

Protect Forests“striving to maintain a healthy forested watershed has proven

time and again to provide a community with clean affordable drinking water”

(Eco-Link, Forests and Water Quality, Volume 19, No. 1)

Benefits of Open Space and Forests• Aesthetics• Increase in property values• Better water quality• Reduced runoff

• healthy tree canopy can absorb first ¼” of rain)

• Better air quality • Carbon sink

• Removes carbon from the air and stores it

• Habitat protection• Habitat corridors• Improved human health through physical activity and relaxation • Safer and more plentiful drinking water• Reduced costs for drinking water supplies• Economic development

• housing• tourism

How do we do this?• Regulation?

• Encouragement?

• Altruism?

• Education?

• All of the above?

Answer: All of the above with emphasis on education

“Give a man a fish, he eats for a day. Teach a man to fish, he eats for a lifetime”

Stormwater Open Space

This is not Stormwater Open Space

Design the System• Determine outcome wanted

• Design system to drive behavior to reach outcome

• In other words, start with the end in mind, and

• Make the path you want people to take, the path of least resistance

Win-Win is Always Best• Instead of strict regulation suggest finding Win-

Win

• Create incentives

• Developer preserves or creates additional open space

• Local government gives something in return

• Increased density?

• Public-private partnership for utility installation?

• Other incentives that either generate more income, help sell product quicker, or reduce costs (time and money)

What else can we do?• EPA Scorecard

• MS4s reviewed current regulations for “green friendliness” in 2012

• Stormwater

• Subdivision

• Zoning

• Policies

• All others related to development

• Ask for copy from your MS4 Stormwater Manager

• Do your regulations and policies need adjustments?

What else can we do?• Meet with Public Water Officials

• Discuss their long range plans and needs

• Ask them what you can do to help them

• Protect water supply

• Protect water quality

• Improve water quality

• Reduce costs

Percentage of Open/Green Space?

Percentage of Open/Green Space?

Percentage of Open/Green Space?

Percentage of Open/Green Space?

Percentage of Open/Green Space?

Percentage of Open/Green Space?

Something to think about• Is a rainforest a rainforest because of the rain or the forest?

(Like the “chicken or the egg” question-which came first?)