Sustainable Infrastructure and Low Impact Development Images Nancy Givens and Dr. Terry Wilson, WKU Center for Environmental Education and Sustainability DEGRADATION Increased runoff & flooding STEWARDSHIP Groundwater and surface water contamination Increased sedimentation Decreased infiltration Degraded vegetation Soil loss and compaction Increased Irrigation needs Degradation vs. Stewardship: Effective land management practices can preserve and restore ecosystems, promote water and air quality, and contribute to human and other species well-being Beauty Habitat Restoration Improved soil conditions Cleaner air and water Reduced potable water irrigation needs Increased water absorption and filtration Objectives 1. Create an integrated green infrastructure model that retains, filters, and reuses all stormwater on the site 2. Provide professional training and community education on NPS pollution + LID techniques 3. Involve residents and the community in project + shared stewardship of environment 4. Seek building policy revisions for KyHfH Notable Features Amphitheater Walking trails / connection with Greenways Green infrastructure + Green housing Community Center Housing and access roads restricted to perimeter Rain gardens, community gardens, edible landscaping Educational programming Shared functions: bike swap, car sharing program Low Impact Development (LID) Techniques • Conservation design • Permeable Pavers and Asphalt • Underground cisterns, rain barrels, and piping • Rain gardens and community gardens • Native plants, edible plants, and tree cover • Sedimentation basin, retention and detention basins BMP: Conservation Design Land use development that allows sustainable development while preserving the natural features and creating a park like environment for residents. Benefits: Preserves open space and vista, creates or protects habitat for wildlife, creates natural spaces for recreation and reflection; puts people in communities in contact with nature. Design & Siting Considerations: • Unique, scenic or significant natural features are preserved • Homes and lots are laid out to maximize visual and physical access to the natural spaces • Homes are clustered to maximize open space (up to 50%) Cost Considerations: • When well-designed, generally not higher cost then traditional developments BMP: Permeable Pavers Alternate paving systems that integrates stormwater management with an aesthetic amenity on the site Benefits: Slows stormwater; reduces runoff volume; permits infiltration into ground; resources groundwater Design & Siting Considerations: • Best suited to low traffic, low speed areas • Avoid in high pollution areas since direct filtration is uses • Pavers hold up well to freeze/thaw cycles Cost Considerations: • Initial costs may exceed traditional paving materials, but long-term maintenance are less over the 25-year life cycle • Costs offset by reduced amount of stormwater structures and land to manage stormwater that is needed BMP: Permeable Asphalt Resembles conventional asphalt but has more air spaces that allow water to pass and into an underlying stone reservoir that stores the surface runoff. Benefits: Reduces stormwater runoff volume and peak discharge rates; allows water to infiltrate into the ground; reduces pollutant transfer Design & Siting Considerations: • Best suited for low to medium traffic areas • Avoid areas with high amount of sediment or erosion • Less prone to cracking or buckling from freezing and thawin • Don’t use in areas with high potential for contamination Cost Considerations: • Initial costs may exceed traditional materials, costs may be offset by reduced amount of stormwater structures; costs vary depending on site size, design, piping, and soil characteristics BMP: Underground Cistern Allow stormwater to be treated as a resource and harvested for reuse, reducing water demand; water collected is for non-drinking Benefits: Capture rainwater for reuse; reduce stormwater runoff volume and discharge rate; provide alternative source for irrigation needs Design & Siting Considerations: • Designed with a filter to capture debris; pumps to facilitate reuse; and overflow systems to convey excess rainwater • Lifespan estimated at 20-50 years • To maximize storage drain cistern between storm events Cost Considerations: • Without installation, cost can range from $250 for 200-gal. to $5,000 for 10,000 gal. cistern. Long-term savings include lower water usage fee. BMP: Rain Barrels A system to collect and store rainwater from roofs that would otherwise be lost to runoff and diverted to storm drains and streams; relatively simple and inexpensive to construct Benefits: Collects and stores water from storm events during periods of drought; provides ample and free “soft water” for gardens; diverts water from storm drains thereby reducing runoff; saves money and improves the environment Design & Siting Considerations: • Can be placed under any downspout; elevate from ground • Drain after storm events so water can be stored at next event • A longer hose will give more flexibility in where you water Cost Considerations: • Costs range from $60 to $250 for purchased, or make your own for about $35; some are designed as art forms. BMP: Rain Gardens A shallow depression that biofilters stormwater runoff rather than allowing it to flow into storm drains and surface water where it can cause erosion, pollution, or flooding. Benefits: Prevents erosion, pollution, flooding; filters water and improves water quality; slows runoff rate; beautifies site Design & Siting Considerations: • Where soils are not permeable enough to allow water to drain and filter properly the soil should be replaced: 60% sand, 20% compost, 20% topsoil • Subsurface drainage from a thick bed of gravel may be used • Native plants are recommended because they generally don’t require fertilizer and are drought-resistant Cost Considerations: • Moderate costs but high benefits BMP: Community Gardens Promote healthy communities, provide nutritious food and food security especially for low income persons. Contribute to the preservation of open space and create recreational opportunities. Benefits: Provide nutritious food; give control over the quantity and kind of pesticides used; increase food security; save $$; increase community bonds; get people outside; improve health Design & Siting Considerations: • Plots should be ‘leased’ per season • Some aspects can be shared, e.g., tools and equipment; watering according to a schedule • Soil preparation is crucial, and as you sow so you shall reap Cost Considerations: • Generally, a great return for the amount invested BMP: Native Plants Plants that evolved naturally in a particular area and are well-suited to the soil, moisture, and weather conditions. Their root systems help rainfall percolate into the soil; reducing erosion and runoff. This improves water quality Benefits: They are low-maintenance, require less water, are in natural balance with other species and are often quite beautiful. Design & Siting Considerations: • Many are heat and drought tolerant • Plant to provide habitat to butterflies, birds, and other wildlife Cost Considerations: • These can be planted from seed, transplanted from the wild (if access), or purchased. Reduced water and maintenance needs offset the purchase costs. BMP: Tree Cover Planting trees provides shading and can moderate the microclimate. Trees prevent direct sunlight, reduce surface temperature, create habitat, and have strong aesthetic appeal. Benefits: May be the most economical and practical method to provide shading benefits to buildings and outdoor areas; they are inexpensive and fairly easy to plant. The main disadvantages are they are slow-growing and require some maintenance. Design & Siting Considerations: • Plant where cutting solar gain does the most good • Plant along banks to slow flow rate and increase absorption and filtration • Maintain properly – watering, pruning, (naturally) fertilizing Cost Considerations: • Generally inexpensive and easy to maintain BMP: Edible Landscaping An alternative to conventional landscaping that can be just as beautiful but offers fruits and vegetables for home use. Benefits: Enjoy fresh and flavorful home-grown foods; control the quantity and kind of pesticides used; increase food security; save $; get outside, interact with the world, and have fun Design & Siting Considerations: • Choose a variety of fruit and nut trees, berry bushes, vegetables, herbs, and edible flowers • Most like well-drained soil and at least 6 hours of full sunlight • Plants will require a certain amount of attention – watering, pruning, (naturally) fertilizing, pest-control, harvesting • Plant to maximize the decorative garden aspects Cost Considerations: • Well-maintained plants and abundant yields will minimize costs BMP: Sedimentation Basin A controlled stormwater release structure formed by constructing an embankment of compacted soil across a drainageway and installing an outlet structure and pipe - detains runoff long enough for the majority of sediment to settle. Benefits: Effective at trapping medium and coarse-grained particles; helps to control runoff; relatively easy to construct Design & Siting Considerations: • Drainage area should be at least 10 acres • Must be cleaned regularly to maintain effectiveness • Not particularly effective for fine silts or clay soils or for intense rainfall events Cost Considerations: • Relatively inexpensive to construct; good maintenance practices required BMP: Retention Basin A constructed pond that maintains a permanent pool of water for stormwater control plus aesthetics Benefits: Reduces stormwater runoff volume and rate; reduces sediment, solids and metals; Improves water quality; aesthetic and recreational benefits; provides wildlife habitat Design & Siting Considerations: • Drainage area should be at least 10 acres • Cannot be placed on steep or unstable slopes • Should have a sediment forebay and proper depth • Proper lining is required Cost Considerations: • Costs vary due to value of land, size, and complexity of basin design BMP: Detention Basin Holds stormwater and then slowly releases it to the receiving stream after a storm event. Benefits: Effective in controlling peak stormwater discharge rates and therefore downstream flooding; some water quality control Design & Siting Considerations: • Drainage area should be at least 10 acres • Should be designed to properly drain so no standing water • Approval may be needed by dam safety authorities • Fencing may be needed Cost Considerations: • A low-cost BMP for water quality control. Cost will vary depending on the value of the land, location, size, and design Strength of Project = Partners WKU – CEES, Planning and Construction, Landscaping, WKYUPBS KY HfH + HfH BG WC Mayor’s Office + BG Dept. Public Works BG City Schools BGGreen Partnership for a Sustainable Cmmty. Bluegrass PRIDE River Basin Coordinator + Team