Monday, February 2, 2009

Drawbacks of curb and gutter ignored by most city street standards. Foreclosures offer second chance to do it right

Please click on image to ENLARGE photos for reading sign and seeing detail of January 31, 2009, photos of the Creek Meadow at Springwoods failed development site.

Traditionally, road and lot drainage systems have been designed to convey storm runoff away as quickly as possible to reduce localized ponding. This drainage concept, using curb-gutter-sewer systems, has led to downstream flooding, erosion, water-quality degradation, reduced groundwater recharge and stream baseflow, and aquatic habitat destruction. This paper examines the pros and cons of curb-gutter-sewer systems and qualitatively compares various forms of open ditch -swale drainage alternatives with the conventional curb-gutter-sewer drainage system. These open ditch - swale drainage alternatives not only provide drainage functions but also promote infiltration, trap sediments, and reduce flow velocity along the drainage path. Thus, they can reduce erosion, enhance runoff quality, and increase groundwater recharge. However, they usually require a wider right-of-way than the conventional curb-gutter-sewer systems and may not be suitable for sites with steep topography or erosive soils. For sites that are suitable for the application of these alternative drainage systems, their environment functions make them more attractive than the conventional curb-gutter-sewer system.
Technical study of drawbacks of conventional curb and gutter summarized

Please click on image of storm drain and curb and gutter with a curb cut that brings water OFF the adjacent absorbent wetland to the street and drain opening and thus rapidly to nearby, springfed Clabber Creek in Fayetteville, Arkansas. This fails to recharge the stream in the normal way and destroys the ability of the land to prevent flooding downstream and to cleanse the water. The alternative would be a slightly higher street with curb cuts pouring the water onto the wetland rather than draining the wetland. Such areas obviously should not be developed intensively. Old-fashioned construction of buildings without filling for a base and without a concrete foundation would be the only way anything should be allowed on such prairie soil. Well-engineered modern versions of the simple construction of houses on piers should be designed and required. Old streets in many parts of the city that have existing streetside ditches should be improved only with careful protection of vegetated swales and must include education of the owners and residents of adjacent property on the value of protecting their existing potential "natural stormgardens" rather than seeking to drain their land. Teaching good stewardship of wetland is a city responsibility.
The city's approval of the Creek Meadow at Springwoods subdivision plan was shortsighted and the failure of the developer to complete the project is a blessing because it offers a chance to see that any development that new owners of the foreclosed property propose will be minimized and revised to follow progressive wetland-protection and stormwater-retention concepts.

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