Chapter 4 Habitats
Many rivers that were once free flowing are now flooded by reservoirs, severely fragmenting habitat and often isolating populations of species above and below the impoundment. Indirect effects to the unimpounded portions of the system include disruption of natural thermal and hydrologic regimes and a reduction in downstream flows. These impacts will have a negative impact on aquatic habitat and will reduce base flow available for drinking water for downstream municipalities. Drought conditions over the past several years have required many municipalities to evaluate their water supply and capacity to meet demand. Residential and commercial growth in urban areas generates new demands for water supplies. An increase in the number of proposed reservoirs is a potential consequence of reduced water supply and increased demand. Water Quality. Erosion and the resultant sedimentation are the largest sources of nonpoint source pollution in most aquatic systems. Sources of erosion include disturbance from development activities and agriculture land uses. Residential development can increase erosion during the construction process and is a source of increased impervious surfaces in the watershed, which can also increase erosion. The Piedmont ecoregion is highly developed, and most watersheds have high percentages of impervious surfaces that contribute to increased runoff, stream and bank erosion, pollution inputs, and increased flashiness of streams and rivers. Livestock access to streams contributes heavily to bank erosion, sedimentation, and nutrient input. Timber harvests and poorly constructed and maintained timber roads are additional sources of erosion if proper controls are not used and maintained. Potential increased air temperatures and therefore, increased water temperatures can lead to algal blooms in aquatic systems, which diminishes stream oxygen availability. The increased water temperature alone can cause a decline in DO that can lead to fish kills, whether as a direct result of increased water temperature or as a secondary effect of algal blooms (DeWan et al. 2010; Band and Salvesen 2009) . Many of the water quality and water quantity impacts resulting from climate change are analogous to impacts from economic development and population growth in North Carolina. Climate change is predicted to decrease rainfall and therefore, limit water supply. Growth and development, however, have been increasing and will continue to increase water supply demands. Historical stream flow patterns—already being altered due to rapid urbanization— are projected to be further altered due to climate change impacts. An increase in impervious surfaces due to roads, parking lots, homes, and businesses increases the amount and speed of runoff being delivered into aquatic systems. Decreased groundwater recharge between storms due to impervious surfaces leads to a decrease in stream base flows. Runoff from urban areas often contains higher concentrations of nutrients (such as nitrogen and phosphorus), sediment, metals, hydrocarbons, and microbes. Invasive Species. The introduction of any invasive species is cause for concern, and the prevalence of warmer water temperatures may increase the likelihood of the invasion of additional exotic species, once thought to be non-threatening because the winters were too
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2025 NC Wildlife Action Plan
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