Although Duluth's hillside may come as an exception with its lower temperatures and cooling effect of nearby Lake Superior, many urban centers exhibit a “heat island effect” resulting from heat-retaining materials such as black roofs and waste heat generated from energy usage. While many urban developments respond to increased temperatures with costly and temporary measures such as energy-intensive air conditioning, some areas are making efforts to stop heat absorption at the source. White roofs have proven very effective at reflecting solar radiation, lowering building temperatures significantly. Yet another approach gives way to successful mitigation of the heat island effect in addition to several other benefits. "Green roofs", layers of vegetation spanning building rooftops, serve several purposes contributing to the sustainability of the structures they cover as well as their surrounding communities. Green roofs help to absorb rainwater and filter out pollutants and contaminants, control storm water runoff, reduce heating costs by adding insulation value, lower cooling demands by natural evaporative cooling, create habitat for wildlife, and also increase agricultural space in urban areas. The extensive environmental benefits of green roofs are echoed by great financial rewards in the form of energy savings, tax credits, and increased property value, though the community benefits can be equally rewarding. Green roofs are a great opportunity to build lasting social relationships between local community members and organizations, holding endless possibilities for projects ranging from community garden programs to urban agriculture projects that help feed the poor or disadvantaged.
The Duluth Motor Pool Green Roof Project
St. Louis County is taking steps towards a more sustainable community with its green roof project taking place above the Motor Pool Building in downtown Duluth. The project is a pilot program between the Department of Natural Resources (DNR), Minnesota Pollution Control Agency (MPCA), and the Western Lake Superior Sanitary District (WLSSD) for storm water control. Grants for the project were approved and received from the Minnesota Coastal Council as well as the Northeast Minnesota Sustainable Development Partnership. Additional funds were rewarded to the Duluth Community Garden Program who now tends to the gardens along with the Duluth Thunderbird-Wren House. Together they grow a variety of plants, devoting a large portion of the green roof to raising fruits and vegetables. Accompanied by the longest running PV array in Northeastern Minnesota, the Motor Pool rooftop serves as a model for future green roof projects in the region.
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