Analysis of Instream Flows for the Sulphur River: Hydrology, Hydraulics & Fish Habitat Utilization
Total Page:16
File Type:pdf, Size:1020Kb
Analysis of Instream Flows for the Sulphur River: Hydrology, Hydraulics & Fish Habitat Utilization Final Report Volume I – Main Report Submitted to the US Army Corps of Engineers in fulfillment of Obligation No. W45XMA11296580 and TWDB Contract No. 2001-REC-015 Tim Osting, Ray Mathews and Barney Austin Surface Water Resources Division Texas Water Development Board July 2004 Executive Summary This report addresses potential impacts of water development projects to the hydrology, aquatic habitat and flood plain in the Sulphur River basin. Proposed main-channel reservoir projects in the basin have the potential to cause significant changes to the hydrological regime and information presented in this report will aid future planning efforts in determining the magnitude of the changes. Regional characteristics of the Sulphur River basin are presented along with historical stream flow records that are analyzed for changes in historical flow regime over time. Recent and historical studies of the fisheries of the lower Brazos River are reviewed and discussed. A total of five different analyses on two different datasets collected in the Sulphur River basin are presented. Two Texas A&M University (TAMU) studies were based upon fish habitat utilization data collected in two areas of the Sulphur River over one season. One area, downstream of the confluence of the North and South Sulphur Rivers, was channelized and the other area, downstream of the proposed Marvin Nichols I Reservoir site, was unchannelized. Two additional TAMU studies were based upon fish habitat utilization data collected in two areas (channelized and unchannelized) of the South Sulphur River near the proposed George Parkhouse I Reservoir site. A fifth analysis completed by the Texas Water Development Board (TWDB) compared all data collected for the earlier four TAMU studies on a common basis. Four analyses showed the fish communities to be composed largely of habitat generalists, while the fifth showed some degree of specialization. Rare species were identified and habitat utilization of fluvial specialists were investigated. To aid future efforts to quantify the effects of a change in flow regime on the availability of fish habitat on the Sulphur River, two representative stream segments were chosen: Site 1 was located on the main stem Sulphur River just downstream of the confluence of the North and South Sulphur Rivers, and Site 2 was located on the short stretch of the main channel between the proposed dam site and the upper reaches of Wright Patman Reservoir. A spatial habitat model was developed for each site capable of mapping hydraulic mesohabitats and structural habitats. Two-dimensional hydraulic models were developed for both sites to quantify depth and velocity variation within each study reach. The habitat model was applied to depth and velocity data in order to quantify the area of available habitat for a range of flow rates. To investigate the significance of flow regime on the flood plain riparian areas, the area of inundation was quantified for six frequently-occurring flood events. The flood events ranged from that historically occurring once every three years to events that occur several times a year, each event lasting at least 14 continuous days. A previous contract study enabled the inundated area of each vegetation type in the basin (e.g., bottomland hardwood forest, Oak-Hickory forest, etc.) to be quantified, and the analysis presented in this report enabled the frequency and duration of occurrence of inundation to be quantified. Additional field data would improve this preliminary analysis. This report describes preliminary and necessary steps required to complete a full instream flow study. Conclusions based on these studies are discussed and recommendations are made for design and implementation of future studies that will establish flow regime recommendations for maintenance of instream flows. Future studies are to be conducted under directives of Texas Senate Bill 2 with the cooperation of the Texas Parks and Wildlife Department, Texas Commission on Environmental Quality and interested cooperators. iii Table of Contents Page Executive summary iii 1. Introduction 1 1.1 Proposed water development projects 3 1.1.1 George Parkhouse I and II 3 1.1.2 Marvin Nichols I and II 4 2. Regional description 5 2.1 Sulpher River basin 5 2.2 Climate 11 2.3 Land Use 11 2.4 Soils and erosion 11 2.5 Hydrology 13 2.6 Water quality 18 2.7 Ecologically unique river segments 19 2.8 Threatened and endangered species 20 3. Site selection and hydraulic analysis 21 3.1 Hydraulic Analysis Sites 21 3.1.1 Site 1 22 3.1.2 Site 2 25 3.2 Hydraulic modeling 28 3.2.1 RMA-2 28 3.2.2 Data Collection 29 3.2.3 Mesh generation 29 3.3 Hydraulic assessment 34 3.3.1 Site 1 34 3.3.2 Site 2 35 4. Fisheries overview: historical and recent studies 39 4.1 Biological sampling sites 39 4.1.1 South Sulphur River near Jim Chapman Lake 39 (Gelwick and Burgess 2002) 4.1.2 South Sulphur River near the confluence 40 (Gelwick and Burgess 2002) 4.1.3 Main stem Sulphur River downstream of the confluence 40 (Gelwick and Morgan 2000) 4.1.4 Sulphur River downstream of proposed Marvin Nichols I 41 (Gelwick and Morgan 2000) 4.2 Flow rates for fish sampling events 41 4.3 Instream fisheries 44 v 4.4 Excerpts from Gelwick and Morgan (2000) 45 4.5 Excerpts from Morgan (2002) 51 4.6 Excerpts from Gelwick and Burgess (2002) 63 4.7 Excerpts from Burgess (2003) 67 4.8 Discussion and analysis of visually classified mesohabitats 81 5. TWDB fisheries analysis 83 5.1 Development of a mesohabitat model 84 5.2 Incorporation of structural habitat data 90 5.3 Area of available habitat 94 5.3.1 Available habitat at Site 1 94 5.3.2 Available habitat at Site 2 94 5.4 Species distribution within hydraulic mesohabitats and structural 99 sub-mesohabitats 5.4.1 Spatial heterogeneity of mesohabitats 99 5.4.2 Discussion of species distribution amongst habitats 101 found by earlier studies 5.4.3 Species distribution across sampling sites and mesohabitats 105 5.4.4 Species distribution across seasons 106 5.4.5 Habitat utilization of rare species and fluvial specialists 107 5.4.5.1 Rare species 107 5.4.5.2 Fluvial species 110 6. Periodic flood plain inundation 135 6.1 Value of Sulphur River flood plain habitat to fisheries 135 6.2 Value of Sulphur River flood plain habitat, bottomland hardwood 137 Forest and riparian zone 6.2.1 U.S. Fish and Wildlife Service (1985) 138 6.2.2 Texas Water Development Board/Texas Parks and Wildlife 138 Department (Lui et al., 1997) 6.2.3 Norris and Linam, 2000 & Others 139 6.3 Development of a flood plain inundation model 140 6.3.1 Spatial data sources 140 6.3.2 Determining inundated areas 142 6.4 Significance of modeled flood surfaces 151 6.4.1 The 68.6 percentile flow event 151 6.4.2 The 76.7 percentile flow event 152 6.4.3 The 88.3, 94.3 and 99.7 percentile flows 153 6.4.4 Flow rate duration and exceedance analysis 156 6.5 Area of flood plain 162 6.5.1 George Parkhouse I 164 6.5.2 South Sulphur River downstream of George Parkhouse I 167 6.5.3 George Parkhouse II 170 6.5.4 North Sulphur River downstream of George Parkhouse II 173 6.5.5 Sulphur River upstream of Marvin Nichols I 176 vi 6.5.6 Marvin Nichols I 179 6.5.7 Sulphur River downstream of Marvin Nichols I 182 6.5.8 Marvin Nichols II 184 6.5.9 White Oak Creek downstream of Marvin Nichols II 187 7. Conclusions and recommendations 189 7.1 Conclusions 189 7.1.1 Hydrology 189 7.1.2 Aquatic habitat 190 7.1.3 Hydraulic modeling for aquatic habitat 191 7.1.4 Periodic flood plain inundation 191 7.2 Recommendations 192 7.2.1 Hydrology 192 7.2.2 Aquatic habitat 193 7.2.2.1 Habitat sampling recommendations 193 7.2.2.2 Habitat analysis recommendations 193 7.2.2.3 Additional aquatic analyses 194 7.2.3 Hydraulic modeling for aquatic habitat 194 7.2.3.1 Field data within the bounds of an intensive 194 analysis site 7.2.3.2 Note on ephemeral nature of bed forms 195 7.2.3.3 Note on hydraulics near large woody debris 196 7.2.3.4 Hydraulic model formulation 196 7.2.4 Flood plain inundation modeling 197 Acknowledgements 199 References 201 vii List of Tables Page Table 2.1 – Frequency analysis of historical daily flows at the Talco gage. 15 Table 3.1 – Flow rates modeled at Site 1. 34 Table 3.1 – Flow rates modeled at Site 2. 35 Table 4.1 – Biological sampling dates, flows, and percentiles for Summer season. 42 Table 4.2 – Biological sampling dates, flows, and percentiles for Winter season. 43 Table 5.1 – Criteria used to delineate mesohabitats. 89 Table 5.2 – Structural sub-mesohabitats used in GIS analysis 90 Table 5.2 – Habitat area within Site 1. 97 Table 5.3 – Habitat area within Site 2. 98 Table 5.4 – List and organization of tables presented in this chapter 100 Table 5.5 - Absolute abundance of fishes in CHANNELIZED reaches of the 111 Sulphur River by season and by collection period Table 5.6 –Absolute abundance of fishes in UNCHANNELIZED reaches 112 of the Sulphur River by season and by collection period Table 5.7 – Absolute abundance of rare fish species in CHANNELIZED 113 reaches of the Sulphur River by season and by collection period Table 5.8 – Absolute abundance of rare fish species in UNCHANNELIZED 114 reaches of the Sulphur River by season and by collection period Table 5.9 - Relative standardized abundance of fish species in 115 CHANNELIZED reaches of the Sulphur River by season and by collection period Table 5.10 – Relative standardized abundance of fish species in 116 UNCHANNELIZED reaches of the Sulphur River by season and by collection period