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HomeMy WebLinkAboutBig Hickory Dams A&BA"V JUN 1 2 2 a e??ti ® North Carolina Wildlife Resources Commission Charles R. Fullwood, Executive Director MEMORANDUM TO: James W. Caldwell, EI, Asst. State Dam Safety Engineer Division of Land Resources, Land Quality Section FROM: Ron Linville, Regional Coordinator Habitat Conservation Program DATE: June 4, 2003 SUBJECT: Big Hickory Dams A& B, Unnamed Tributary Robertson Creek, Surry County These comments are provided in accordance with provisions of the Clean Water Act of 1977 (33 U.S.C. 466 et. seq.), the Fish and Wildlife Coordination Act (48 Stat. 401, as amended; 16 U.S.C. 661-667d) and the Dam Safety Law of 1967 (GS 143-215.23 et. seq.). I conducted a site visit on June 4, 2003 with Brian Shugart, the owner and Ms. Denise Poulous, a wetland consultant. During the visit, it was determined that the indicated location of the dams is incorrect. The ponds are proposed for the small drainage just to the east of the indicated area. Any impact to jurisdictional waters appears to be non-existent or minimal. According to the owner and his consultants, well water will be used to keep the ponds full. Although we prefer to maintain natural geomorphic stream functions when jurisdictional impacts occur, we have reviewed the subject project and find no cause for objecting to the design and specifications of the dam with the following provisions: 1) Portions of the basin are classified as Outstanding Resource Waters by the Division of Water Quality. Sediment and erosion control measures should adhere to the design standards for sensitive watersheds (15A NCAC 413 .0024). 2) Thermal elevation should be minimized to the extent practicable for water released from the proposed ponds. The provision of native trees and shrubs along shorelines (excluding dam structures) as buffers can reduce pollutant loading and decrease thermal impacts. Attached is a Fisheries Management Fact Sheet that may be useful as the project is planned and developed. 3) The use of fertilizers and lime should be limited to Natural Resources Conservation Service recommended application rates so that nutrient impacts to downstream waters are minimized as much as possible. 4) If concrete will be used, work must be accomplished so that wet concrete does not mix with stormwater or stream waters. Big Hickory Dams A & B, 2 June 4, 2003 UT Robertson Creek 5) To the extent practicable, any buffer zone revegetation should use native plants. Littoral shelves with native riparian vegetation are recommended for improving safety, aquatic edge habitat and additional shallow water shading. Attached is a list of plants routinely recommended for piedmont stormwater ponds which may also be useful during pond site planning. 6) If the dam impacts jurisdictional waters, project sponsors should be contact the US Army Corps of Engineers (COE) at 919/876-8441 and the NC Division of Water Quality (DWQ) at 336-771-4600 to determine if a COE 404 Permit and DWQ 401 Certification that could be required for this project. Providing the dam stays above the existing access gravel driveway, 404 permitting should not be difficult (in our opinion). Any stream or wetland mitigation required at this site should be should be coordinated with the Corps of Engineers and the Division of Water Quality. Thank you for the opportunity to review and comment on this project. If you have any questions regarding these comments, please contact me at 336/769-9453. Attachments: Fisheries Management Fact Sheet 2003 - Pond Issues General Piedmont Plant Recommendations for Stormwater Ponds Cc: Todd Tugwell, COE Matthew Gantt, DLR Cyndi Karoly, DWQ Mark Cantrell, USFWS Big Hickory Dams A & B, 3 June 4, 2003 UT Robertson Creek General Piedmont Stormwater Mine/Pond Plant Recommendations Revegetation of disturbed soils should include the following seed mixtures for both soil stabilization and wildlife benefits: Spring/Summer Mixture, May 1- Sept. 15 Fall[Winter Mixture, Sept. 15 - April 30 Browntop mullet 20 lbs/a Winter Wheat 120 lbs/a Kobe lespedeza 201bs/a Kobe lespedeza 20 lbs/a Switchgrass* 5lb/a Switchgrass* 51b/ac Add to fall or spring plantings: `Tioga' Deertongue (Panicum clandestinum) at a rate of 71bs. Pure Live Seeds (PLS) per acre. * On slopes less than 3:1 use Switchgrass, slopes greater than 3:1 use Orchard Grass or Creeping Red Fescue. Korean lespedeza may be substituted for Kobe in colder climates. Other native species may be appropriate depending on soil, slope, and ecoregion. Add one of the following to the above mixture Creeping Red Fescue 5 lbs/acre Ladino Clover* * 5 lbs/acre Atlantic Coastal Panic Grass 5 lbs/acre (PLS) Alfalfa** 5 lbs/acre (requires fertilizer containing Boron) ** Lime & fertilize disturbed areas according to NRCS soil test results. Follow planting guidelines as appropriate and necessary. Depending on elevation and region, other native species may be appropriate. A mixed native forest should be planted instead of a monoculture plantation during site reclamation to provide enhanced wildlife habitat diversity. Trees and shrubs (1 year bare root seedlings) should be planted randomly at a minimal rate of 100 trees per acre and at a minimal rate of 150 per acre around jurisdictional waters or wetlands. The following native plant species should be considered for woody vegetation as they will enhance habitat values: Native Pine* Red Cedar Black Gum American Holly Dogwood Hickory Sumac Red Maple Oak (sp) Viburnum Green Ash Ironwood Black Cherry Persimmon Black Walnut Willow (sp) Locust (sp) Mulberry Native Plums (sp) Serviceberry Other species may be utilized depending on site requirements and availability. Pines* should not exceed 15% of the reforestation. No more than 20% of the tree species should be of a single species. An 80% success rate is acceptable over five years. A wildlife tree seedling pack is available from the NC Forest Service. s Fisheries Management Fact Sheet 2003 What: Environmental Impacts Caused by Ponds. Ponds provide aesthetic benefits, water for crop irrigation and livestock, as well as fishing opportunities and wildlife habitat. However, ponds can be detrimental to fish, wildlife, and water quality if constructed improperly_ Ponds that are created by damming streams, and ponds of any type that continuously release water back into a stream can be especially harmful. Where: Poorly designed ponds can impact aquatic life and water quality statewide, but the impacts are greatest around ponds located in and near coldwater streams in the mountains and foothills. When: Historically, ponds were built on farms to supply water for livestock and crop irrigation. In recent years, the rate of pond construction has increased as more and more people move to the mountains and build ponds to improve the appearance of their property or to provide fishing opportunities. WhY: There are two major problems that ponds can cause. First, a pond created by damming a. stream impedes the migration of many aquatic organisms along the strew, including fish, mussels, and amphibians. The second problem is related to the release of warm water from ponds. Because impounded water warms more quickly than moving water, water is considerably warmer in ponds than in free flowing streams. Furthermore, the warmest water within a pond will be at the surface, while the coolest water will be found near the pond bottom. Within most ponds, the water that flows out of the pond and back into adjacent streams is drawn off the surface. When this warm surface water is released, water tempemures within the stream increase, harming trout, smallmouth bass, and other species adapted to cooler water temperatures. While there can be thermal impacts below ponds that only release water periodically during heavy rain events, the impacts will be most severe below ponds that constantly release water. How to build Po ds without darnmina the stc•.rm channel: To ensure t1w the ihigration of aquatic organisms within streams are not blocked when building a pond; consider locating new ponds away from streams and using surface runoff, springs, or water pumped from wells as water sources. Ponds can also be filled by building them adjacent to a stream and diverting or pumping a small portion of the stream water into the pond to fill it. Water should only be diverted into the pond continuously while the pond is being filled. Once the pond is filled, water should only be diverted into the pond as needed to maintain water levels. How to reduce the thermal imaacts of Pond outflows: Thermal impacts caused by ponds that continuously release surface water into streams can be reduced in ponds that are equipped with a standpipe to regulate water levels. The installation of a bottom drawoff device (see diagram on next page) over the existing standpipe helps reduce the temperature of water released by the pond by siphoning off the cooler water found near the pond bottom. Furthermore, a bottom drawoff also helps prevent fish kills in ponds by removing the stagnant, low oxygen water from the pond bottom. The drawoff pipe needs to be large enough in diameter so that the cross-sectional area of the space between the two pipes is greater than the cross-sectional area of the drainpipe. The pipe needs to be long enough to reach into the cooler/deeper waters of the pond, and should leave at least a couple feet of clearance above the bottom to avoid future interference from sediment accumulation. The drawoff pipe should be constructed of a relatively light but rigid material (aluminum is best). Heavy pipes are difficult to mount and put extra strain on the standpipe that could eventually cause its failure. If the drawoff pipe material isn't sufficiently rigid it may collapse under the suction pressure. Typically drawoff pipes are mounted by inserting two crossbars through the pipe 6-12 inches from the top end, then putting the drawoff pipe over the standpipe so that these crossbars rest on the top of the standpipe. Three bolts or pins can be inserted into the pipe several feet down from the top to serve as spacers that will keep the drawoff pipe vertical and centered on the standpipe. Bottom water withdrawal devices do have their limitations. Ponds that are very shallow and/or small may not benefit shire the water temperatures near the bottom and at the surface will be more similar. 111 i€ =he ou?'=c? *' a.po id is going dire ;ily. nt6.-a ate ; then the Water should be aerated by routing it to splash onto rocks or other hard, jagged surfaces as it re-enters the stream. More information concerning pond construction and management is found in the "Pond Management Guide" Published by the N.C. Wildlife Resources Commission and the N.C. Agricultural Extension Service. This guide can be obtained online at www ncwildlife or or by calling 919.733.3633.