Low Impact Development Tour
Low Impact Development (LID), also known as conservation site design or green infrastructure, is a process of sustainable development that conserves and protects natural resources. LID manages rainwater where it falls by integrating natural systems and best management practices (BMPs) into the site. By having less water run off the land, non-point source pollution is reduced, watersheds are protected, and water quality is improved. LID is especially important in urban and urbanizing areas where it is crucial to promote water conservation, protect our waterways and enhance green space.
Lawrence Tech is home to numerous LID techniques including a green roof, bioswale, porous pavers, naturalized areas, cisterns, and rain gardens (see map). These techniques are highlighted in a new stormwater education trail funded by the Erb Family Foundation. The trail will provide educational benefits to a broad spectrum of the population including students, citizens, public policy makers, planners, landscape architects and engineers.
LID on Campus
Lawrence Tech's Southeast Michigan LID Interactive Mapping Website
Presentation on Lawrence Tech's LID
Topics
1. Rain Garden (Bioretention Cell) - This mature rain garden was planted with a mixture of native Michigan plants in 2007 as part of a Rouge River National Wet Weather Demonstration Project (RRNWDP). It is a retrofit around an existing catch basin and reduces runoff by allowing stormwater to soak into the ground as opposed to flowing into the storm drain. This garden is 2.5 ft deep with a planting soil that consists of 50% sand, 30% topsoil, and 20% compost.
2. Rain Garden - This rain garden is also a component of the RRNWDP grant, but with a different planting soil mixture (80% compost and 20% sand) and a different plant palette. It is also a retrofit around an existing catch basin and reduces runoff. The garden exhibits less surface pounding than Rain Garden #1 (slower surface infiltration), but ultimately stores more water in its pore space.
3. Bioswale - This bioswale was completed in 2005 as part of the Student Services Center landscaping. The bioswale is 3 ft deep and consists of native grasses and shrubs over engineered soils designed to filter water run-off. The bioswale was designed to handle a 10 year storm event before overflowing into existing stormwater systems.
4. Rain Garden - This rain garden was constructed in June 2011 as part of a student project. It consists of five native plant species hand selected for site conditions. LTU will retrofit the garden in 2012 to include "dry" river rock beds to facilitate the flow of stormwater into the garden.
5. Cistern/Stormwater Harvesting - The green roof (#6) retains approximately 70% of annual precipitation, with the remainder draining into this 10,000 gallon underground cistern. The cistern recycles the "grey" water into the Student Services Center to flush toilets.
6. Green Roof - The Student Services Center has a 10,000 square foot Hydrotech Garden Roof which includes a 4-inch granular soil that supports nine different species of sedum ground cover. The green roof has been monitored since 2007 and has proven effective in water management and energy savings.
7. Porous Paver System - This outdoor dining patio was constructed in 2009 with Uni-Lock Eco-Stone pavers. The porous pavers allow water to infiltrate into the engineered stone layer below. The 6-inch layer is designed to hold stormwater and allow it to infiltrate into the native soil layer below with zero run-off.
8. Riparian Buffer Zone - Lawrence Tech planted two acres of riparian grow zones in 2009 as part of a RRNWDP grant. This area is the smaller of the two zone and is vegetated with more than 20 species of native plants and grasses to protect a small tributary of the Rouge River flowing through campus. The buffer plays a key role in improving water quality by filtering run-off.