Trinity River Basin Research Articles

Impacts of Max-Stable Process Areal Exceedance Calculations to Study Area Sampling Density, Surface Network Precipitation Gage Extent and Density, and Model Fitting Method

Max-stable process (MSP) models can be fit to data collected over a spatial domain to estimate areal-based exceedances while accounting for spatial dependence in extremes. They have theoretical grounding within the framework of extreme value theory (EVT). In this work, we fit MSP models to three-day duration cool season precipitation maxima in the Willamette River Basin (WRB) of Oregon and to 48 h mid-latitude cyclone precipitation annual maxima in the Upper Trinity River Basin (TRB) of Texas. In total, 14 MSP models were fit (seven based on the WRB data and seven based on the TRB data). These MSP model fits were developed and applied to explore how user choices of study area sampling density, gage extent, and model fitting method impact areal precipitation-frequency calculations. The impacts of gage density were also evaluated. The development of each MSP involved the application of a recently introduced trend surface modeling methodology. Significant reductions in computing times were achieved, with little loss in accuracy, applying random sample subsets rather than the entire grid when calculating areal exceedances for the Cougar dam study area in the WRB. Explorations of gage extent revealed poor consistency among the TRB MSPs with modeling the generalized extreme value (GEV) marginal distribution scale parameter. The gauge density study revealed the robustness of the trend surface modeling methodology. Regardless of the fitting method, the final GEV shape parameter estimates for all fourteen MSPs were greater than their prescribed initial values which were obtained from spatial GEV fits that assumed independence among the extremes. When two MSP models only differed by their selected fitting method, notable differences were observed with their dependence and trend surface parameter estimates and resulting areal exceedances calculations.

The Use of Historical Data and Global Climate Models to Assess Historical and Future Surface Water and Groundwater Availability in the Trinity River Basin in Texas

This paper describes the results of a study that was done by the USGS to assess recent (2017) water availability, forecast long-term trends in water availability, assess changes in water availability, and forecast future water availability in the Trinity River Basin in Texas. The Trinity River Basin surface water model and Trinity River alluvium aquifer (TRAA) groundwater model were created to evaluate future conditions under different global climate models (GCM). The results of this study show minimal overall changes in water availability for both surface water and groundwater. Trend analyses using historical data (1900–2017) indicated an increase of annual precipitation on the watersheds that drain into the reservoirs in Regional Water Planning Group C. However, the Trinity River Basin surface water model GCM ensemble mean annual precipitation indicates a downward trend, resulting in a downward trend in surface runoff. Additionally, the GCM ensemble mean for the Trinity River Basin surface water model and the TRAA groundwater model both indicate a downward trend in recharge while the TRAA model GCM ensemble mean indicates an upward trend in the amount of groundwater leaving the aquifer to rivers and streams resulting in an upward trend of cumulative storage change.

Prioritizing streams: The impacts of in-kind mitigation rules on an ecosystem offset market

Extensive regulations have aimed to protect streams and wetlands threatened by development activities in the United States. However, failures to offset ecosystem damage with restoration of similar ecosystems (i.e., “in-kind mitigation”) have impeded success of these policies. How do policies enforcing in-kind mitigation requirements – e.g., prioritizing stream mitigation for stream impacts – alter the structure of mitigation markets? What impacts do they have on the broader market for stream and wetland mitigation? We studied the mitigation market of Texas’s Upper Trinity River Basin (USA), where regulators implemented novel, in-kind stream mitigation requirements in 2013. Drawing on impact and mitigation data (2007–2019), we used hurdle, breakpoint, and ordinary least squares regression models to statistically examine the long-term effects of this policy on the Basin’s stream and wetland mitigation markets, including demand and supply of mitigation bank credits. We found this policy spawned an enduring stream mitigation market, while driving declines in stream impact extents and wetland mitigation credits sold and supplied. These findings have implications for other districts seeking to establish in-kind mitigation requirements while protecting the entrenched investments of existing mitigation firms.

Optimizing Water Supply through Reservoir Conversion and Storage of Return Flow- A Case Study at Joe Pool Lake

Maintaining an adequate water supply is one of the key challenges faced by the Dallas-Fort Worth Metroplex, where increasing population and rising water demand have elevated the vulnerability of the communities to water shortages. In this paper, we conducted a preliminary study exploring the possibility of converting flood storage in the Joe Pool Lake (JPL) as a means to improve water supply reliability and achieve better cost efficiency. This study employs a mixed integer linear programming (MILP) approach that considers the costs of meeting conversion demand and supply requirements over the northern portion of the Trinity River Basin. It includes trade-offs between capturing and storing natural flow versus return flow from the treatment facilities of the Trinity River Authority (TRA). A set of hypothetical prices and demand figures with the record drought of 1940-1996 considered to test the LP model. The optimal strategy yields expansion of JPL and associated storage-diversion on an annual basis. Also, the outcomes of the analyses suggest that, while the conversion would have a positive impact on water availability, storing the return flow might not produce sufficient cost savings; unless higher prices were imposed on the stored-return flow.

Statistical Assessments of River Flow Alterations and Environmental Flow Standards

A water availability modeling (WAM) system consisting of the Water Rights Analysis Package (WRAP) and input datasets for all Texas river basins has been used for statewide, regional, and operational planning and water allocation regulatory purposes for many years. The modeling system was recently expanded to support integration of environmental flow requirements in comprehensive water management. A strategy is presented in this paper for combining the WRAP-WAM modeling system with data management and statistical analysis tools to expand capabilities for analyzing stream flow alterations and the effects on flows of environmental flow standards. A Trinity River Basin case study demonstrates the utility of the modeling and analysis strategy in addressing relevant issues in the river systems of Texas and elsewhere. Dams and reservoirs constructed on the Trinity River and tributaries supply water for the Dallas–Fort Worth and Houston metropolitan areas, which are among the most rapidly growing large metro areas in the United States. Ecologically relevant statistical analyses of observed flows presented in this paper are designed to quantify flow alterations. Analyses of simulated flows representing natural and specified conditions of development are performed to assess the impacts of both water resources development and the establishment of environmental flow standards.

The utility of zooarchaeological data to guide listing efforts for an imperiled mussel species (Bivalvia: Unionidae: Pleurobema riddellii)

AbstractThe status of species in freshwater systems shift over time due to natural and anthropogenic causes. Determining the magnitude and cause of these shifts requires a long‐term perspective. This process is complicated when there are also questions about the taxonomic validity of a species. Addressing these issues is important because both can undermine conservation and management efforts if incorrect. Pleurobema riddellii, Louisiana Pigtoe, is under review for protection under the U.S. Endangered Species Act, but its status in the Trinity River basin, where the taxon was described, remains in doubt due to questions about its taxonomy and occurrence within this basin. To address these questions, we compared shell morphometrics of P. riddellii dating to the late Holocene with modern P. riddellii, late Holocene Fusconaia sp., and modern Fusconaia sp. using multivariate analyses to test associations between the putative morphotypes. Based on these analyses, we demonstrate that P. riddellii was likely present in the Trinity during the late Holocene, which indicates questions about its taxonomic validity or presence in this basin are unfounded. Our study further highlights the role zooarchaeological studies can play in status assessments and their utility in better understanding biogeographic patterns for rare species.

Evaluation of ecological, stressor and social factors for the prioritization and restoration of Trinity River Basin watershed

Public interest in the restoration of impaired water bodies is growing, and as such, it is critical to understand the causes of impairment and the likelihood of successful restoration. Restoration efforts often focus on a specific factor (stressors) of the impaired water body without including equally important but often overlooked societal and ecological factors. In this study, segment-specific indicators such as stressor exposure, ecological capacity, and societal traits were used to perform a screening analysis to evaluate the restoration potential of fifteen impaired segments in the Trinity River Basin. Data obtained for each impaired segment were normalized and compared using simple ranking, three-dimensional bubble plots, and mapping. Results indicate that when individual indices were rank-ordered, water segments that ranked low on the stressor index and high on the ecological and social indices had the best chance of restoration. While the three-dimensional bubble plot analysis of interrelated ecological, stressor, and social indices suggests that watershed segments with high ecological and low stressor indices may not necessarily be prime candidates for restoration. Their ranking on the social index score determines their priority for restoration. The results of the screening analysis show the utility of the recovery potential screening tool in prioritizing the restoration of impaired water bodies.

SILENE NELSONII, A NEW LARGE-FLOWERED SPECIES FROM THE TRINITY RIVER AREA OF NORTHWESTERN CALIFORNIA, USA, AND A RE-EVALUATION OF S. BOLANDERI GRAY

Silene nelsonii M.R. Mesler, M.S. Mayer, and S.K. Carothers (Caryophyllaceae), a species with large, day-blooming flowers from the Trinity River Basin of northwestern California, is described and illustrated. In the past, plants assignable to this new species have been referred to incorrectly as S. bolanderi A.Gray or S. hookeri Nutt. subsp. bolanderi (Gray) Abrams, names that rightfully apply to another member of the Silene hookeri complex. Here we argue that both S. nelsonii and S. bolanderi are worthy of recognition as separate species based on morphological distinction and a molecular phylogenetic analysis. Silene nelsonii differs from S. bolanderi by its more deeply lobed, white petals; lack of well-developed coronal petal appendages; densely ciliate petal bases; and shorter, sometimes branched sepal hairs. We present a key to the five members of the S. hookeri complex, all of which are in some degree rare in California and worthy of conservation concern.

Archeological Investigations in the Upper Trinity River Basin in Parker County, Texas

Homer Norris (1929-2018), a commercial artist by profession and a life-time resident of eastern Parker County, in North-Central Texas, in the South Fork and Clear Fork drainages of the upper Trinity River basin, roamed the landscape from at least 30-50 years ago in search of archeological evidence of Native American use and settlement in the basin. He took and maintained detailed notes, records, and drawings of the sites he found and the artifacts he recovered, as well as pertinent information on the context of finds, including those noted eroding out of stream cut banks and in stream beds of the South Fork and Clear Fork in the Anetta-Aledo areas of Parker County, about 15 miles west of Fort Worth, an area of about 5 miles on a side. This information, made available by his daughter Lanie Garmon of Aledo, Texas, from his archeological investigations is detailed herein, along with a summary of how his investigations contribute to a fuller understanding of the native history of this region of Texas.

Streamflow Drought Interpreted Using SWAT Model Simulations of Past and Future Hydrologic Scenarios: Application to Neches and Trinity River Basins, Texas

AbstractIn water resources and environmental management, hydrologic indexes are often valued as decision support tools because of their practical interpretability. This is true with the streamflow ...

Assessing the Skill of Medium-Range Ensemble Precipitation and Streamflow Forecasts from the Hydrologic Ensemble Forecast Service (HEFS) for the Upper Trinity River Basin in North Texas

Abstract To issue early warnings for the public to act, for emergency managers to take preventive actions, and for water managers to operate their systems cost-effectively, it is necessary to maximize the time horizon over which streamflow forecasts are skillful. In this work, we assess the value of medium-range ensemble precipitation forecasts generated with the Hydrologic Ensemble Forecast Service (HEFS) of the U.S. National Weather Service (NWS) in increasing the lead time and skill of streamflow forecasts for five headwater basins in the upper Trinity River basin in north-central Texas. The HEFS uses ensemble mean precipitation forecasts from the Global Ensemble Forecast System (GEFS) of the National Centers for Environment Prediction (NCEP). For comparative evaluation, we verify ensemble streamflow forecasts generated with the HEFS forced by the GEFS forecast with those forced by the short-range quantitative precipitation forecasts (QPFs) from the NWS West Gulf River Forecast Center (WGRFC) based on guidance from the NCEP’s Weather Prediction Center. We also assess the benefits of postprocessing the raw ensemble streamflow forecasts and evaluate the impact of selected parameters within the HEFS on forecast quality. The results show that the use of medium-range precipitation forecasts from the GEFS with the HEFS extends the time horizon for skillful forecasting of mean daily streamflow by 1–3 days for significant events when compared with using only the 72-h River Forecast Center (RFC) QPF with the HEFS. The HEFS forced by the GEFS also improves the skill of two-week-ahead biweekly streamflow forecast by about 20% over climatological forecast for the largest 1% of the observed biweekly flow.

Old Water Becoming New Again

The reuse of treated wastewater effluent for municipal supply is not a new idea in Texas, having been contemplated for at least sixty years. However, its importance has grown in recent decades as traditional surface water sources have become fully subscribed. Reuse is recognized as a significant source of future supply for Texas in the 2017 Texas State Water Plan. The law related to reuse is, however, still very much a developing subject. Recent administrative actions and judicial decisions have better defined the contours of the entitlements necessary to reuse effluent discharged to state-owned water courses. In the midst of this continued legal evolution, water suppliers in the Trinity River basin are actively implementing reuse projects using the river as a conveyance for the indirect reuse of discharged effluent.

Teleconnection between low flows and large-scale climate indices in Texas River basins

Understanding low flow variability is critical for assessing water quality and health of riverine ecosystems in a river basin. Low flows are dependent on human water abstraction as well as the climate variability. This paper investigates the changing nature of low flows and their association with large-scale climate variability for different watersheds in the State of Texas, USA. For this purpose, we employed trend, wavelet analysis and linear as well as nonlinear correlations to identify important changes in low flow characteristics for three stream-gauging stations selected from different (i.e. Brazos, Colorado and Trinity) river basins located in Texas for the time period of 1916–1959 and 1960–2003. We also investigated the teleconnections between low flow variables and the large-scale climate indices (NINO 3.4, SOI and PDO) using cross wavelet analysis as well as their linear and non-linear correlation relationship. Our results indicated that the low flow magnitudes have shown considerable different characteristics for selected river basins during two separate time periods (1916–1959 and 1960–2003). Based on cross wavelet analysis, we identified that the low flows in selected stations of Colorado and Trinity River basins are likely to be influenced by all three large-scale climate indices. In addition to that, we identified that low flows are more nonlinearly associated with climate indices. Among the selected River basins, the stronger association between low flows and large scale climate indices are observed for Trinity River basin. The results from this study can help in better understanding of low flow hydrology and their potential relationship with large scale indices.

Assessment of Flood Control Capabilities for Alternative Reservoir Storage Allocations

Multiple-purpose reservoir system operations are based on the conflicting objections of maximizing storage contents to assure high water supply reliability and maximizing empty storage space to mitigate flood risk. Reallocation of storage capacity between conservation and flood control purposes provides a strategy for optimizing limited available storage capacity in response to growing demands and changing objectives. A modeling and analysis methodology is presented in the article for assessing alternative reservoir storage allocations. Flood control capabilities are evaluated in terms of the probabilities of overtopping the storage capacities of the reservoirs in the system. Water supply capabilities are quantified in terms of reliability metrics. Flood control analysis capabilities are implemented in a modeling system originally created for detailed assessments of water supply capabilities. The methodology is applied to a system of eight multiple-purpose reservoirs in the Dallas and Fort Worth metropolitan area in the Trinity River Basin of Texas in the United States. The generalized modeling system and analysis methods are applicable to reservoir systems located anywhere including systems that may be very complex.

The Newt Smith Site (41HE78), Henderson County, Texas

The Newt Smith site (41HE78) is probably an ancestral Caddo cemetery and habitation site in the Coon Creek valley of the Post Oak Savannah in the Trinity River basin in East Texas. In April 1931, a Mrs. A. G. Hughes of Poynor, Texas, donated a single Caddo vessel to The University of Texas. That vessel is in the collections of the Texas Archeological Research Laboratory at The University of Texas at Austin (TARL).

The Caddo Occupation of the L. B. Miller Farm (41HE4/55) in the Post Oak Savanna and Trinity River Basin in East Texas

The L. B. Miller Farm site (41HE4/55) is a Late Caddo period Frankston phase Caddo habitation site and small cemetery on an upland landform (400 ft. amsl) in the Coon Creek-Catfish Creek drainage in the Post Oak Savannah of the Trinity River basin. The ancestral Caddo artifact collections from the site at the Texas Archeological Research Laboratory at The University of Texas at Austin (TARL) include four vessels from a burial feature, sherds from two unreconstructed ceramic jars found in habitation contexts, and 178 ceramic sherds from midden deposits.

Dissolved organic carbon and dissolved organic nitrogen concentrations and exports upstream and downstream of the Dallas–Fort Worth metropolis, Texas, USA

Concentrations and export of dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) from terrestrial landscapes to near-coastal zones vary with land use. Information on (DOC) and (DON) concentrations and exports from urban ecosystems is sparse; thus, their source from within urbanised watersheds such as soil or vegetation or from permitted sewage discharge is unknown. We examined DOC and DON concentrations and exports in four gauged subwatersheds in the humid subtropical, upper Trinity River basin, upstream and downstream of the Dallas–Fort Worth metropolis in Texas, USA. Annual average DOC concentrations ranged from 5.7±0.4 to 6.4±0.8mgL–1 and DON concentrations ranged from 0.31±0.05 to 0.33±0.14mgL–1. Dissolved organic carbon exports, which included permitted sewage discharge, ranged from 522kgkm–2 year–1 above Dallas–Fort Worth to 3637kgkm–2 year–1 below Dallas–Fort Worth. Permitted effluent discharge contributed between 1 and 35% of DOC loading above and below the Dallas–Fort Worth metropolis. DON exports ranged from 27 to 179kgkm–2 year–1 above and below Dallas–Fort Worth respectively. There was difficulty apportioning permitted effluent-discharge contribution to DON because of the transformations among nitrogen-species. A moderate but significant relationship was found between DOC and sodium concentrations (R2=0.45; P<0.0001; n=40) and between DOC and potassium concentrations (R2=0.45; P<0.0001; n=40). Dissolved organic nitrogen also displayed a significant relationship with sodium (R2=0.33; P<0.001; n=40) and potassium (R2=0.59; P<0.001; n=40), suggesting that increases in these cations to aquatic ecosystems may induce increases in DOC and DON concentrations. Although DOC export was significantly correlated with medium-density urban land use (r=0.96; P<0.05: n=4), DON export was not (r=0.93; P>0.05; n=4), suggesting that land-management practices and permitted point-source discharges have a significant effect on aquatic DOC and DON concentrations and exports derived from urban watersheds.

Modeling Water-Quality Loads to the Reservoirs of the Upper Trinity River Basin, Texas, USA

The Upper Trinity River Basin (TRB) is the most populated river basin and one of the largest water suppliers in Texas. However, sediment and nutrient loads are reducing the capacity of reservoirs and degrading water quality. The objectives of this study are to calibrate and validate the Soil and Water Assessment Tool (SWAT) model for ten study watersheds within the Upper TRB in order to assess nutrient loads into major reservoirs in the basin and to predict the effects of point source elimination and urbanization on nutrient loads through scenario analyses. SWAT performed reasonably well for the current condition except for two out of five tributaries in the Eagle Mountain watershed and total phosphorous OPEN ACCESS Water 2015, 7 5690 in Richland-Chambers. The impacts of simulated scenarios varied within watersheds. Point-source elimination achieved reductions ranging from 0.3% to 24% in total phosphorus and 1% to 56% in total nitrogen received by the reservoirs. Population and development projections were used to examine the impacts of urbanization on each watershed. Projected urbanization in 2030 had large effects on simulated total phosphorus loads in some watersheds, ranging from a reduction of 1% to an increase of 111%. Projected urbanization also affected simulated total nitrogen loads, from a reduction of 3% to an increase of 24%. One limitation of this study is the lack of long-term, up-to-date water quality data due to discontinued water-quality monitoring stations. Although careful considerations were given to the adjustment of parameter values reflecting various aspects of the nutrient processes, further data collection will enhance modeling study for assessment of these watersheds’ water resources and environmental problem.

Ecoregional, catchment, and reach-scale environmental factors shape functional-trait structure of stream fish assemblages

Patterns of association between functional traits and environmental gradients can improve understanding of species assemblage structure from local to regional scales, and therefore may be useful for natural resource management. We measured functional traits related to trophic ecology, habitat use, and life-history strategies of fishes and examined their associations with environmental factors in the Brazos and Trinity River basins in Central Texas. We also examined the relationship between functional diversity of fish assemblages and indices of biotic integrity and habitat quality. Environmental characteristics at the local reach and catchment scales, including the extent of forested area in the watershed, amount of land developed for urban and agricultural uses, stream size, substrate characteristics, and availability of riffle and pool habitats, were significantly associated with functional trait composition of fish assemblages. Broad physiographic differences between ecoregions also had a large influence on taxonomic and functional assemblage structure. In general, the volume of functional trait space occupied by fish assemblages was greatest in streams with high habitat quality scores located within landscapes having less alteration from agriculture and urban development. Distributions of functional traits in fish assemblages might provide an additional basis for assessment of stream condition in relation to environmental impacts.

The Doug Martin Site (41AN88), a Late Caddo Period Frankston Phase Settlement in the Trinity River Basin in East Texas

The Doug Martin site (41AN88) is a Late Caddo period Frankston phase settlement on a southern-flowing tributary to the Trinity River in the Post Oak Savannah of East Texas (Figure 1). Several avocational archaeologists from the Palestine, Texas, area, principally including Clyde Amick, worked at the site in the early 1980s, and donated a collection of artifacts from the site, along with some information about the work done there, to the Texas Archeological Research Laboratory at The University of Texas at Austin (TARL) in November 1985.