LAKE & RESERVOIR ASSESSMENTS CAPE FEAR RIVER BASIN University Lake Intensive Survey Unit Environmental Sciences Section Division of Water Quality June 4, 2009 TABLE OF CONTENTS TABLE OF CONTENTS .................................................................................................... 2 FIGURES .......................................................................................................................... 4 TABLES ............................................................................................................................ 5 GLOSSARY ...................................................................................................................... 6 OVERVIEW ....................................................................................................................... 8 ASSESSMENT METHODOLOGY .................................................................................... 8 ASSESSMENT BY 8-Digit HUC HUC 03030002 Reidsville Lake ...................................................................................................... 10 Lake Hunt .............................................................................................................. 11 Lake Brandt ........................................................................................................... 12 Lake Townsend ..................................................................................................... 13 Lake Higgins ......................................................................................................... 14 Lake Burlington (Stony Creek Reservoir)........................................................... 15 Lake Cammack (Burlington Reservoir) .............................................................. 16 Graham-Mebane Reservoir .................................................................................. 17 Lake Mackintosh ................................................................................................... 18 Cane Creek Reservoir .......................................................................................... 20 Jordan Lake .......................................................................................................... 21 University Lake ..................................................................................................... 24 HUC 03030003 High Point Lake .................................................................................................... 26 Oak Hollow Lake (High Point Reservoir) ............................................................ 27 Randleman Lake ................................................................................................... 28 Sandy Creek Reservoir ........................................................................................ 31 Rocky River Reservoir ......................................................................................... 32 HUC 03030004 Harris Lake ............................................................................................................ 33 Old Town Reservoir .............................................................................................. 34 Bonnie Doone Lake .............................................................................................. 35 Kornbow Lake ....................................................................................................... 36 Mintz Pond ............................................................................................................ 37 Glenville Lake ....................................................................................................... 38 DWQ Intensive Survey Unit Page 2 8/6/2009 HUC 03030005 Salters Lake .......................................................................................................... 39 Jones Lake ............................................................................................................ 40 White Lake ............................................................................................................. 41 Boiling Springs Lake ............................................................................................ 42 HUC 03030006 Bay Tree Lake (Black Lake) ................................................................................. 43 Singletary Lake ..................................................................................................... 44 HUC 03030007 Cabin Lake ............................................................................................................ 45 Appendix A. Cape Fear River Basin Lakes Use Support Matrix For 10/1/2004 - 9/31/2008 Appendix B. Cape Fear River Basin Lakes Use Support Data DWQ Intensive Survey Unit Page 3 8/6/2009 Figures Figure 1. Microscopic view of Aphanizomenon ........................................................ 21 Figure 2. Surface scum of Aphanizomenon ............................................................... 21 Figure 3. Lyngbya woolei from High Point Lake........................................................ 27 Figure 4. Locations of DWQ sampling sites on Randleman Lake ............................ 30 Figure 5. Creeping Rush .............................................................................................. 35 Figure 6. Proliferating Spikerush ................................................................................ 35 Figure 7. Sandhills Millfoil ........................................................................................... 36 Figure 8. Brownish-red organic material covering aquatic plants ........................... 39 DWQ Intensive Survey Unit Page 4 8/6/2009 Tables Table 1. Algal Growth Potential Test Results for Graham-Mebane Reservoir, July 9, 2008 ....................................................................................... 18 Table 2. Algal Growth Potential Test Results for Lake Mackintosh, July 9, 20087 ........................................................................................................ 19 Table 3. Algal Growth Potential Test Results for Cane Creek Reservoir, June 19, 2008 .................................................................................... 20 Table 4. Algal Growth Potential Test Results for Jordan Lake June 13, 2006 ....................................................................................................... 23 Table 5. Algal Growth Potential Test Results for Jordan Lake, June 13, 2007 ....................................................................................................... 23 Table 6. Algal Growth Potential Test Results for University Lake, June 19, 2008 ....................................................................................................... 25 DWQ Intensive Survey Unit Page 5 8/6/2009 GLOSSARY Algae Small aquatic plants that occur as single cells, colonies, or filaments. May also be referred to as phytoplankton, although phytoplankton are a subset of algae. Algal biovolume The volume of all living algae in a unit area at a given point in time. To determine biovolume, individual cells in a known amount of sample are counted. Cells are measured to obtain their cell volume, which is used in calculating biovolume Algal density The density of algae based on the number of units (single cells, filaments and/or colonies) present in a milliliter of water. The severity of an algae bloom many be determined by the algal density as follows: Mild bloom = 20,000 to 30,000 units/ml Severe bloom = 30,000 to 100,000 units/ml Extreme bloom = Greater than 100,000 units/ml Algal Growth A test to determine the nutrient that is the most limiting to the growth of algae Potential Test body of water. The sample water is split such that one sub-sample is given (AGPT) additional nitrogen, another is given phosphorus, a third may be given a combination of nitrogen and phosphorus, and one sub-sample is not treated and acts as the control. A specific species of algae is added to each sub-sample and is allowed to grow for a given period of time. The dry weights of algae in each sub-sample and the control are then measured to determine the rate of productivity in each treatment. The treatment (nitrogen or phosphorus) with the greatest algal productivity is said to be the limiting nutrient of the sample source. If the control sample has an algal dry weight greater than 5 mg/L, the source water is considered to be unlimited for either nitrogen or phosphorus. Centric diatom Diatoms are photosynthetic algae that have a siliceous skeleton (frustule) and are found in almost every aquatic environment including fresh and marine waters, soils, in fact almost anywhere moist. Centric diatoms are circular in shape and are often found in the water column. Chlorophyll a Chlorophyll a is an algal pigment that is used as an approximate measure of algal biomass. The concentration of chlorophyll a is used in the calculation of the NCTSI, and the value listed is a lake-wide average from all sampling locations. Clinograde In productive lakes where oxygen levels drop to zero in the lower waters near the bottom, the graphed changes in oxygen from the surface to the lake bottom produces a curve known as clinograde curve. Coccoid Round or spherical shaped cell Conductivity This is a measure of the ability of water to conduct an electrical current. This measure increases as water becomes more mineralized. The concentrations listed are the range of values observed in surface readings from the sampling locations. Dissolved oxygen The