These sections apply to the Colorado River Watershed in Segment 1428, of the Texas surface water quality standards, including the Colorado River from Longhorn Dam to 100 meters downstream of State Highway 95/State Highway Loop 230 bridge in Smithville, Texas, and all tributaries of that segment of the Colorado River, and to Segment 1427, Onion Creek, and its tributaries, of the Texas surface water quality standards, from its confluence with the Colorado River to the most upstream crossing of Farm to Market Road 165.