The thermocline separates warm, oxygen-rich surface water from cold, oxygen-poor deep water. The photo to the left is from Feb. 21, 2017. Just click to enlarge. In Beaver Lake, the thermocline forms in warm summer months, usually in early June, and persists through about mid-October. Many species of fish will try to locate right above the thermocline. When fishing, you should aim for the thermocline — where the temperature flattens out for a time at a certain depth and you see a more continuous horizontal line in the graph linked to this web page — to find black bass, smallmouth bass, largemouth bass, spotted bass, and crappie. Striped bass, which are cool water fish, will typically be located below the thermocline on the lower end of the lake by the dam.
Beaver Lake Raw Water Quality
Lake water quality is largely determined by the quality of water in the tributaries. Beaver Water District monitors nine tributary sites on a monthly basis. A water quality index (WQI) is a simple and concise method for expressing ambient water quality information and a useful tool for describing the state of the water column, sediments and aquatic life and for ranking the suitability of water for use by humans, aquatic life, wildlife, etc. The District uses a modified version of the Canadian Council of Ministers of the Environment WQI to evaluate tributary condition. The District’s WQI is based on the Arkansas Department of Enviromental Quality’s Assessment Criteria for the White River. The WQI produces a single value between 0 and 100 with increasing values indicating better water quality similar to getting a grade. Values of 95 to 100 are excellent, 80-84 good, 65-79 fair, 45-64 marginal, and 0-44 poor. In 2011, the average WQI values from the tributary sites were fair to good and ranged from 78.9 at White River north of Wyman, Ark., to 89.2 at Middle Fork White River at Black Oak, Ark.