CFE 040802 - Laserfiche WebLink

Browse Search

FALL 2001 � 47 IJ and included the restoration of Grant Run as a part of stormwater does not increase significantly. When of their comprehensive water quality and stream a stream is already affected and there is no place for preservation effort in the county. A "Nature increased storage , as was the case with Grant Run , Works " grant was given by the State of Ohio to the following methods can be used to create a FCSWCD for the restoration of Grant Run . Grove successful flood control and streamside restoration City provided money ( 45 percent ) to match the project . grant funds ( 55 percent ) . Hence , the combined The first phase of restoring Grant Run analyzed objectives of establishing greenways , enhancing stream erosion and determined its " bankfull " width water quality, preventing erosion , protecting private and stream depth . The volume *of stormwater and property, enhancing community appearance , and frequency of flood events ( e . g . , one - year to three - providing more flood storage capacity culminated year floods ) affecting the stream were analyzed . in the pursuit of the Grant Run stream restoration This was very important because all of the succeed - project that was supported by city, county, state , ing levels of measurement depended on having an federal , and private stakeholders . accurate advance estimate of flood width and depth . FACTS OF THE CASE Most small tributaries already affected by devel - Any stream channel that is forced to take on opment have cut down into the streambed ( i . e . , the additional water volumes will eventually have to be first phase of stream erosion ) . When the stream widened , or it will widen itself if nothing else is contacts harder subsoils and rock , it can no longer done . Communities can apply traditional engineer- cut down to increase its size and begins to cut ing solutions to streams with severe erosion by laterally ( see Figure 2 ) . Grant Run had to be replacing slumping stream banks and threatened enlarged laterally to hold more water and decrease bridge embankments with concrete walls and stream velocity. riprap . Such engineering solutions often prove to be temporary, very expensive , and sometimes visually Figure 2 intrusive . Furthermore , they do virtually nothing to BASIC STREAM DYNAMICS ~ _ improve habitat and water quality. STREAM CHANNEL AT BEND Alternatively, streamside degradation can be NEW BANKFULL WIDTH addressed using more natural means of stream OLD BANKFULL WIDTH protection . The Grant Run neighborhood sup - ported an alternative method that would stabilize OUTSIDE STREAM OF CURVE T EROSION stream banks . Stream restoration officials helped ,�.., ... FORCES neighbors of the stream recognized the complex Od CUBIC . Streambed forces acting on the stream and applied the N . dynamic forces of stream hydrology to solve the problem . Grove City and a restoration consultant , working with the FCSWCD , sought to stabilize the stream channel so that it could carry the frequent one - year and two -year floods without erosion or the Restoration Details need for ongoing maintenance . The natural stream The stream channel was redesigned and the restoration techniques used at Grant Run can be stream banks were recontoured ( see Figure 3 ) . To transferred to other jurisdictions , and the lessons minimize disturbance , work was performed learned in the case of Grant Run can inform similar predominately on one side of the stream . The new stream restoration efforts . bankfull limit was given a flatter, wider stream cross - section in order to slow stream water flows Overview and First Steps and reduce erosion . Stream riffles were created to Stream restoration projects should be thought of as help reduce the erosive force of water. As water plans for natural systems infrastructure . Ideally, all falls over rocks and small waterfall - like riffles , of the existing floodplain storage areas—including oxygen is also added to the water. Streambeds that trees , ponds , and wetlands—would be preserved to have been deeply down cut can actually be raised , hold the new runoff generated by suburban devel - if additional width can be accommodated . opment . Streamside vegetation and trees act as a Restoring streamside vegetation and installing buffer to filter and store water during heavy rainfall . erosion controls are key steps that follow the Impervious surfaces should be minimized using redesign and recontouring of the stream . Instead conservation design techniques so that the volume of concrete , the erosion control systems used for