Agenda - 10-03-1983 - Laserfiche WebLink

Browse Search

...... ,...: - . 105 ,:.. .. I_ . Given the proposed changes as reviewed, questions arise as to the benefits and .:., ?:. costs of implementation of the provisions and the overall effectiveness of these measures in a comprehensive watershed protection plan. The Board should, therefore, address the following concerns in their consideration of approval of the proposed --,, changes: -!, 1) Recognizing the current arrangement whereby the County administers the adoptecilSedimentation and Erosion Control Ordinance county-wide, including within the Towns of Carrboro and Chapel Hill, it is deslreable and more t., effectkle to have,iideelly, uniform requirements or, at a minimum, uniformly applicaitale requirements. Variatien in requirements and/of their applicabilire, requires additional staff, time and funding for adequate review and enforceffe.nt. ' 1 .. 2) The adopted Orange County Sedimentation and Erosion Control Ordinance contain. stormwater management provisions only where these provisions parallel erosion control ;provisions or provide substantial erosion protection to receiving channeN accomodating runoff from a site. These provisions are not intended, as a primary purpose, to address water quality, ._ 1 , To clarify this point, stormwater management measures are intended to handle storm runoff to control Its velocity, quantity and quality. Development of a site will generally increase the rate and volume of runoff because the characteristics of the ground surface have been changed. Quality of runoff i- degraded1by the pollutants picked up from Impervious surfaces associated with development. Stormwater management practices,:therefore, involve reducing the ratelof and improving the quality of runoff by detention and infiltration of the runoff. Erosiorrcontrol involves controlling the rate of erosion on a construction site and 'containing the sediment generated by activity on the site. Erosion control can be temporary (silt fences) or permanent (estabIlshirig vegetation). Provision must be made to install permanent erosion control to protect receiving; channels from erosion by the increased runoff from a site. In Orange County this usually is done by using rip-rap at pipe outlets and in receivng channels. It could also be accomplished by using stormwater managemenr techniques of infiltration and detention. The Carrboro proposalecontains a number of provisions requiring stormwater management measures or practices specifically for water quality and not necessari y for erosion control purposes. This implies a considerable expansion of the purpose of the adopted county Sedimentation and erosion control p9ogram and would require substantial review of existing staff 1 policies and procedures and capacity (staff and funding). The Town 1 Chapel Hill presently administers their own stormwater management requiremenIts through their engineering department. This arrangement permits a more comprehensive and efficient approach to the stormwater management issue as Staff is assigned responsibility to review deirelopment- impacts by site and area verify design calculations and field-check installation of practices to meet the intent of the provisions. Some local governing bodies have adopted combined stormwater management and erosion control. ordinances. This istia reasonable approach where the local body has established personnel sufficient for the implementation and, • , particularly where the provisiorsare uniformly applicable throughout the jurisdicti1 jn of the enforcement agency. Orange Cout is presently developing a stormwater management ordinance to be applicable unty-wide. At present, the only stormwater management provisions in place are those associated with performance standards for approval of non- residential developments generally. Those stormwater management measures necessary for erosion control are routinely enforced by the Sedimentation and Erosion1Control division. until such time as a county-wide stormwater management ordinance is developed and perSonnel assigned to its enforcement it is questionable whether the County should include these provisions in the erosion control ordinance. . .. BERMOOMMW ----,—