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Home My WebLink About20021799 Ver 1_More Info Letter_20021115F WAIF O9QG Michael F. Easley, Governor ? William G. Ross, Jr., Secretary North Carolina Department of Environment and Natural Resources '?- Alan W. Klimek, P.E., Director Division of Water Quality Asheville Regional Office WATER QUALITY SECTION Lo U9 November 15, 2002 P L!U NOV 2 0 2002 S Ms. Karen Cragnolin, Executive Director Riverlink, Inc. 170 Lyman Street Asheville, North Carolina 28801 Subject: 401 Certification Review of DOA Permit Application Proposed Whitewater Courses Jean Webb Park and French Broad River Park DWQ Project No. 02-1799 Buncombe County Dear Ms. Cragnolin: Staff of the Division of Water Quality have reviewed the width of the subject application for the proposed water quality impacts to the French Broad River. You are requesting to construct two whitewater training courses by constructing and placing rock structures in the French Broad River downstream of Amboy Road adjacent to the French Broad River Park and underneath the 1- 240 bridges at Jean Webb Park. The purpose of this letter is to provide comments and request additional information listed below: The sketches indicate that structures will be constructed across the width of the river at both locations and the wording indicates that these structures will be grouted. Since concrete (due to its pH) is toxic to fish and other aquatic organisms, how will these structures be grouted and not affect fish and wildlife? 2. There are main MSD of Buncombe County sewer lines and pump station in the vicinity of the structures at the French Broad River Park. How will these utilities be protected from damage during construction and from future flooding events? Recommend you contact the MSD of Buncombe County regarding the location of their sewer lines at both sites. 3. Do you have a certification from the City of Asheville that these structures will not result in a no rise situation during flooding events? Please provide a copy of the certification to this office. 4. The plans and typical details submitted with the application do not include distances, depths, areas, specifications or scale of the structures relative to the French Broad River. Please provide typical details that include these types of specifications. Ms. Karen Cragnolin November 15, 2002 Page Two It would be helpful to include material size (size of boulders) as well as orientation, depths and distances as they relate to the existing channel. 5. A hydrologic, shear stress analysis, sediment transport and /or scour analysis will be necessary based on the bed and bank materials as well as vegetation and channel morphology. The most appropriate method of analysis is dependent upon the type of structure or channel alteration proposed, the bed and bank material, the channel morphology and existing vegetation as well as the location of the structures in relation to the existing bed and bank features. 6. The French Broad River is relatively stable and these activities could result in changes to the hydrology and sediment transport in the river that could 'result in destabilization of the streambed and banks. We are concerned that the proposed structures within the channel could result in a change in the channels' dimension or profile or that there is an increase in channel depth near the banks. Factors that would influence the river's response to these changes are channel slope, floodway slope, sinuosity, channel morphology, bed and bank material, vegetation, sediment supply and bed rock out crops. At a minimum, this would require the development of a site plan at a detailed scale that includes the channels morphological features such as the location of stream banks and existing land contours. The proposed location of each type of structure or channel alteration should also be shown on the site plan. 7. The proposed structures could affect aquatic life movement. How will these structures be installed so as to provide aquatic life movement up and down the river? 8. There is some concern regarding the bank terraced seating and vegetation. The sketch does not provide enough detail on how the vegetation and seating will be intermixed. Why does this seating have to extend into the water? It appears that spectator seating could be located higher on the bank away from the water. Because the proposal is for this to extend below the ordinary high water mark, we have concerns regarding bank stability. Also, we will need to approve the type of plants to be used for bank protection. Please provide a list of plants that are proposed to be used for revegetation. The information listed above is needed before the Division of Water Quality can issue a 401 Water Quality Certification. Unit this information is received and approved we are placing this project on hold for our processing purposes due to incomplete information, in accordance with 15 A NCAC 2H .0507 (h). If you have questions, please call me at 828/251-6208. Sincerely, Michael R. Parker Environmental Specialist xc: Dave Baker-COE Dave Penrose