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studiesCase published 1 the American Institute o 15 Certified Planners 1_ 0It FALL 2001 38 AS E B OOK Restoring a Suburban Stream in Grove itiy, 0h1* 0 By David F. Greene , AICP lanners everywhere are concerned with protecting the environment , especially water resources . We routinely prepare watershed plans , greenway master plans , and regulations to protect riparian corridors . In cases where streams are already degraded , however , engineers tend to lead restoration processes instead of planners . Planners can play a greater role in the restoration of riparian corridors , if they understand the dynamic forces of stream hydrology and some of the causes of streamside degradation as well as provide leadership in coordinating restoration projects . They can also advocate more natural methods of restoration . This case presents the lessons of restoring a suburban stream in Grove City , Ohio , called Grant Run . It describes the impact of changes to Grant Run over time and how the stream was restored , at reasonable cost , to be a Figure I community asset . HISTORICAL SUCCESSION OF GRANT RUN �. _ -- r,� K „ 3 PFF BackgroundIF `"f `�" IF IN How the Stream Became - ' ' Degraded s' Grant Run is a small tributary to the Scioto River in Grove City, a suburb of Columbus , Ohio . Its watershed is only 3 . 7 square miles . HIGHLIGHTS The early presettlement watershed of Grant Run was almost entirely eastern hardwood forest of Beech and In the 1850s , the Grant Run Maple . The bankfull stream dimensions were approximately 8' wide by 8' deep. This was adequate to carry the 1 -3 year stone event because most of the rainfall was absorbed by the tree roots and canopy. Summary : Planners watershed was a forest ( see Figure can manipulate the 1 ) . Before settlement , Grant Run natural environment to repair stream was a small , meandering stream that F '. ; degradation. grew during seasonal flooding to Focus : Watershed about six to eight inches deep and protection , tloodplain about Six feet wide . Such a narrow management, stream stream width was adequate to hydrology, greenways. transport the surface water carried After settlement, fanning and home sites replaced most of the forest. Cultivated fields allow more Timeline : 1850-present during a one - year to three - year storm water runoff resulting in three to four times more water rushing through Grant Run. To hold more water, the stream becomes deeper, by 10- 12 inches and wider by 8-8 feet. Stream trees are undercut storm event on a wooded water by the erosive force of the water and fall into the stream. Water Is more sediment laden and the variety shed . Erosion was minimal because of stream plants and animals diminishes. only about 10 percent of the water k I �_.,% ' � falling in the watershed actually ran v 1 off over land into the stream . While ?i ` the watershed was forested , large amounts of stormwater were stored in the floodplain . The final stage of development has replaced the farmland with grass, roads, driveways and homes. The runoff from impervious surfaces increases to twice the farmland levels eroding a deeper channel and severely undercutting trees that limit channel widening . The stream Is polluted with more sediment and toxic materials from roads, yards and parking lots.