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Mountain Island Lake is formed by the drainage of Lake Norman into the . Although high nutrient levels were found in the McDowell Creek arm of the lake, problematic algal bloom conditions were not generally found (NCDENR 1999). Typical summer stratification on Mountain Island Lake results in dissolved oxygen levels and temperatures of approximately 7 mg/L and 31oC at the surface to 5 mg/L and 28oC at a mid depth of 8 m (Duke Power 2000).

The South Fork Catawba River flows southeasterly beginning in South Mountains State Park at the confluence of Jacob Fork and Henry Fork, both Outstanding Resource Waters. Water quality rapidly degrades in the South Fork Catawba River as it flows downstream through agricultural and industrialized areas (NCDENR 1998). The town of Maiden operates Maiden Lake, a 14-acre (5.7 ha) water supply impoundment, which is a tributary to the South Fork of the Catawba. Maiden Lake is monitored by NCDWQ. Recent surveys indicated that Maiden Lake was hypereutrophic in June, eutrophic in July, and mesotrophic in August (NCDENR 1998). A previous investigation by NCDWQ pursuant to a complaint regarding sediment buildup in the lake indicated that the entire Maiden Lake watershed is degraded (NCDENR 1993).

Lake Wylie receives inputs from the Catawba River as well as the South Fork Catawba River, Long Creek, Crowders Creek, and Catawba Creek. experiences localized sedimentation and nutrient enrichment problems, especially in the Crowders Creek and Catawba Creek arms of the lake (NCDENR 1998). Furthermore, a previous study by NCDWQ and Department of Health and Environmental Control (SCDHEC) indicated that the South Fork Catawba River, Catawba Creek, and Crowders Creek contained elevated nutrient concentrations and were contributing to nutrient loading of the lake (NCDENR et al. 1992). Typical summer stratification on Lake Wylie results in dissolved oxygen levels and temperatures of approximately 8 mg/L and 29oC at the surface to 2 mg/L and 27 oC at a mid depth of 8 m (Duke Power 2000).

C. HABITAT

The Catawba River watershed contains 3,005 mi (4,835 km) of streams and 60,000 acres (24,300 ha) of impoundments in (NCDENR 1998). The Catawba River is formed in the western part of North Carolina in Avery, Burke, Caldwell and McDowell counties and flows south and east before entering South Carolina. The flow of the river is heavily regulated as a result of seven major impoundments located along its watershed in North Carolina. There are also several unregulated tributaries that flow in the system particularly in the upper portion of the watershed.

The seven major impoundments of the Catawba River have a large impact on the habitat present in this system. Each reservoir contains varying degrees of limnetic and littoral habitats. These habitats are a result of natural features and anthropogenic alterations. Lake James, the uppermost reservoir on the system, contains warm- and coolwater fish assemblages as a result of the thermal profiles of its tributaries and the depth of the reservoir. Other reservoirs along the system are dominated by warmwater habitats but still contain lesser amounts of coolwater habitat. Littoral habitats are variable among and within the Catawba River system reservoirs (Table 2). Substrate type, wave action, shoreline slope, water level fluctuations, and human alterations to the near-shore environment mainly influence littoral habitats in the reservoirs.

The tailwaters of each reservoir also support aquatic communities. Physical habitat is often limited, however, in these sections of the river due to low minimum flows and fluctuating temperature regimes resulting from hydropower releases. With the exception of the section of the Catawba River above Lake James, all riverine stretches of the Catawba are affected by dam releases. Physical habitat in the areas immediately below the dams typically consists of large boulders and bedrock. The normal stream