Walker Lake Research Articles

Saving Walker Lake: A Pleistocene Terminal Lake in the Anthropocene

Abstract: Just to the east of the Sierra Nevada mountain range a series of Pleistocene terminal lakes are present in the Great Basin of the intermountain West between the Rockies and the Sierra. Among them is Walker Lake, fed by the branches of the Walker River that flow eastward from their snow-melt sources in the Sierra. The terminal lakes have no natural outlets. Water is lost from the lakes' surfaces by evaporation during the hot summer months in the high desert. Since the arrival of Euro-Americans in the nineteenth century, the diversion of water for agricultural, industrial, and domestic uses from the Walker River has reduced the level of the lake to a point where it no longer supports a once-thriving fishery of native cutthroat trout. In the past, western Nevada Paiute peoples relied on the lake's fish as a food source. In the twentieth century the inland anadromous trout drew sports fishing enthusiasts. Climate change has caused additional strains on the water supply for the lake to the point where many have declared Walker Lake a dead lake with only shrinking shorelines and increased salinization in its future. In response, Nevada's U.S. senator Harry Reid, members of the Walker River Indian Reservation, sport fishing organizations, as well as environmental organizations pushed for legislation from Congress to promote efforts to save the lake in the 1990s. These efforts have produced some promising results.

A fuzzy logic based explicit declustering technique

During the spatial estimation of geoscience resource variables, the quantity or quality of minerals and hydrocarbons can be represented by a broad range of properties, including geochemical, geotechnical, or other physical measures. Preferential sampling within the region of interest causes biased global parameters due to clustered sampling patterns. Unbiased sample distribution is essential for conducting conditional simulations to model uncertainty of spatially distributed attributes, e.g. geochemical content of metal or porosity. Therefore, declustering procedures are applied during resource estimation to estimate an unbiased statistical distribution of the measured variables. Traditional techniques such as cell declustering do not consider grade clustering, i.e., the similarity of measured variables within a spatially clustered neighbourhood. This paper presents a declustering technique that explicitly accounts for spatial clustering and the similarity of measured samples' attributes within these spatially clustered samples. In the proposed method, samples were first classified explicitly into spatial and geochemical (grade) clusters using the Fuzzy c-means algorithm. Declustering weights were derived using the Mamdani based Fuzzy Inference System using various T-norm operations. The technique was applied to the publicly available GSLib and Walker Lake datasets. It was shown that the proposed scheme produced more accurate results than those obtained with the traditional declustering technique.

Novel MLR-RF-Based Geospatial Techniques: A Comparison with OK

Geostatistical estimation methods rely on experimental variograms that are mostly erratic, leading to subjective model fitting and assuming normal distribution during conditional simulations. In contrast, Machine Learning Algorithms (MLA) are (1) free of such limitations, (2) can incorporate information from multiple sources and therefore emerge with increasing interest in real-time resource estimation and automation. However, MLAs need to be explored for robust learning of phenomena, better accuracy, and computational efficiency. This paper compares MLAs, i.e., Multiple Linear Regression (MLR) and Random Forest (RF), with Ordinary Kriging (OK). The techniques were applied to the publicly available Walkerlake dataset, while the exhaustive Walker Lake dataset was validated. The results of MLR were significant (p < 10 × 10−5), with correlation coefficients of 0.81 (R-square = 0.65) compared to 0.79 (R-square = 0.62) from the RF and OK methods. Additionally, MLR was automated (free from an intermediary step of variogram modelling as in OK), produced unbiased estimates, identified key samples representing different zones, and had higher computational efficiency.

Foam-based floatovoltaics: A potential solution to disappearing terminal natural lakes

Terminal lakes are disappearing worldwide because of direct and indirect human activities. Floating photovoltaics (FPV) are a synergistic system with increased energy output because of water cooling, while the FPV reduces water evaporation. This study explores how low-cost foam-based floatovoltaic systems can mitigate the disappearance of natural lakes. A case study is performed on 10%–50% FPV coverage of terminal and disappearing Walker Lake. Water conservation is investigated with a modified Penman-Monteith evapotranspiration method and energy generation is calculated with an operating temperature model experimentally determined from foam-based FPV. Results show FPV saves 52,000,000 m3/year of water and US$6,000,000 at 50% FPV coverage. The FPV generates 20 TWh/year of renewable energy, which is enough to offset all coal-fired power plants in Nevada thus reducing carbon-emission based climate forcing partially responsible for a greater rate of disappearance of the lake. The results of this study, which is the first of its kind, indicate foam-based FPV has potential to play a crucial role in mitigation efforts to prevent the disappearing of natural lakes worldwide.

ESTIMATING THE UNCERTAINTY OF KRIGING ESTIMATES: A PRACTICAL REVIEW AND THE PROPOSAL OF TWO NOVEL-APPROACHES

This paper presents two novel kriging-based methods to measure the uncertainty associated with geostatistical estimates. Both approaches combine the Kriging Variance (KV), which is a good summary of the spatial configuration of the data, with a second component which locally measures the data dispersion. The first proposed method, referred to as the Combined Index (CI), merges KV with the local conditional distribution estimated by median Indicator Kriging. The other method is named Combined Variance II (CVII) and it is an adaptation of the originally proposed Combined Variance, where the equation used to merge KV and the Interpolation Variance was replaced. The two proposed methods are compared to other approaches available in the literature in a case study using the widely known Walker Lake dataset. The results indicate that both proposed methods outperformed the other tested solutions. The CVII index outperformed its original formulation in all the tested scenarios.

Recovery of meteorites using an autonomous drone and machine learning

AbstractThe recovery of freshly fallen meteorites from tracked and triangulated meteors is critical to determining their source asteroid families. Even though our ability to locate meteorite falls continues to improve, the recovery of meteorites remains a challenge due to large search areas with terrain and vegetation obscuration. To improve the efficiency of meteorite recovery, we have tested the hypothesis that meteorites can be located using machine learning techniques and an autonomous drone. To locate meteorites autonomously, a quadcopter drone first conducts a grid survey acquiring top‐down images of the strewn field from a low altitude. The drone‐acquired images are then analyzed using a machine learning classifier to identify meteorite candidates for follow‐up examination. Here, we describe a proof‐of‐concept meteorite classifier that deploys off‐line a combination of different convolution neural networks to recognize meteorites from images taken by drones in the field. The system was implemented in a conceptual drone setup and tested in the suspected strewn field of a recent meteorite fall near Walker Lake, Nevada.

Comparison of 1-D analytical solutions and a numerical model for quantifying hyporheic exchange flux using the temperature tracer method

Recently, the use of temperature tracer methods to investigate hyporheic exchange in rivers has attracted widespread attention. The quantification of the hyporheic exchange flux using temperature has been a topic of interest. Based on a summary and elaboration of the one-dimensional (1-D) analytical models for quantifying the hyporheic exchange flux based on the temperature tracer method, a hydrothermal coupling numerical model for the hyporheic zone considering the overall model of a river is further constructed. Combined with the water level and temperature time-series monitoring data collected from relevant rivers in the Walker Lake Basin in the United States, the effectiveness of the constructed numerical model in simulating the temperature and seepage patterns in the hyporheic zone is verified. Based on the verified hydrothermal coupling numerical model, the differences in the quantification of the vertical hyporheic exchange flux between different models are compared and analyzed. In addition, a sensitivity analysis based on the orthogonal test method is carried out to investigate the uncertainty of the 1-D analytical solution model. Finally, the advantages and disadvantages of the 1-D analytical model and the numerical model are discussed from the perspective of theoretical analysis. The results show that the constructed numerical model can be used to effectively characterize the heat transfer and fluid flow patterns in the hyporheic zone. When the result from the numerical model is not considered, the l-D analytical model based on the Hatch amplitude method is an ideal model for quantifying the vertical hyporheic exchange flux using temperature. The sensitivity analysis results reveal that the volumetric heat capacity of the soil (Cs) and the porosity (n) are relatively sensitive parameters for the Hatch solution.

An enhanced dual IDW method for high-quality geospatial interpolation

Many geoscience problems involve predicting attributes of interest at un-sampled locations. Inverse distance weighting (IDW) is a standard solution to such problems. However, IDW is generally not able to produce favorable results in the presence of clustered data, which is commonly used in the geospatial data process. To address this concern, this paper presents a novel interpolation approach (DIDW) that integrates data-to-data correlation with the conventional IDW and reformulates it within the geostatistical framework considering locally varying exponents. Traditional IDW, DIDW, and ordinary kriging are employed to evaluate the interpolation performance of the proposed method. This evaluation is based on a case study using the public Walker Lake dataset, and the associated interpolations are performed in various contexts, such as different sample data sizes and variogram parameters. The results demonstrate that DIDW with locally varying exponents stably produces more accurate and reliable estimates than the conventional IDW and DIDW. Besides, it yields more robust estimates than ordinary kriging in the face of varying variogram parameters. Thus, the proposed method can be applied as a preferred spatial interpolation method for most applications regarding its stability and accuracy.

Multimetric approach in the effects of small impoundments on stream water quality: Case study of Faylor and Walker Lakes on Middle Creek, Snyder County, PA

AbstractIn recent years, dams have received extensive scrutiny for their effects on stream and river systems throughout the United States. Dams vary greatly in size and scale, but investigations often focus on large‐scale dams due to their visibility in the public eye and pronounced impact. This can result in smaller and less impactful impoundments being overlooked, despite the cumulative effects these dams can have on higher order aquatic systems. Two small water impoundments: Walker and Faylor Lakes located, respectively, on the north and west branches of Middle Creek in Snyder County; Pennsylvania have demonstrated an impact on Middle Creek. This study focused on using onsite physical properties, grab samples for chemical analysis and macroinvertebrate samples to determine and compare the effects of the two impoundments on Middle Creek. Both upstream and downstream sites from the dams were sampled. All sites were sampled for physical variables using the YSI Multimeter and chemical concentrations of several cations and anions using Ion Chromatography (IC). A Water Quality Index (WQI) was constructed based on 11 different parameters. All parameters were positively correlated. Data show that the physical and chemical changes to the streams, are caused by the dams and are affecting the biological communities in the downstream water course. Walker Lake was found to have a much greater negative impact on the north branch of Middle Creek causing degradation to the water in relation to certain parameters. Greater concentrations of NH4+, BOD5 and a decreasing WQI downstream of the Walker Dam, as well as several different macroinvertebrate indices indicate this negative impact. Faylor Lake Dam did not have a large impact on the west branch of Middle Creek with regard to any particular variable measured. Overall, small reservoirs can have substantial impacts on the streams they impound especially when considering the morphology and design.

Accommodation of Plate Motion in an Incipient Strike‐Slip System: The Central Walker Lane

AbstractGeodesy shows that ∼7 mm/yr of dextral shear is accumulating across the Central Walker Lane in the absence of through‐going strike‐slip faults. To better understand how this shear is accommodated, we describe and quantify the patterns and slip rates of active faults extending between the Lake Tahoe and Walker Lake basins. Lidar data and geomorphic mapping show linear fault traces and stepping fault geometries consistent with the accommodation of dextral oblique‐slip motion along the Wassuk and Smith Valley faults, whereas the Mason and Antelope valley faults are primarily dip‐slip. Vertical slip rates based on cosmogenic ages in Antelope, Smith, and Mason valleys are 0.5+0.5/−0.3, 0.5+0.7/−0.4, and 0.04+0.05/−0.03 mm/yr, respectively. A strike‐slip fault in the Pine Grove Hills has a dextral slip rate of 0.3–0.8 mm/yr. The remaining unaccounted‐for shear is expected to be accommodated by off‐fault deformation, including block rotations, broad co‐seismic warping, and complex rupture patterns. Together these faults form a left‐stepping en echelon series of dextral, oblique, and normal faults that extend from south of Walker Lake to north of Lake Tahoe, similar to patterns observed in the initial stages of dextral shear laboratory models. GPS profiles spanning the entire Walker Lane are compared to these new and previously published slip rates, and show that while kinematic efficiency is ~60% and ~90% in the Northern and Southern Walker Lane, respectively, it is only ~25% in the Central Walker Lane.

Builders, tenants, and squatters: the origins of genetic material in modern stromatolites.

Micro-organisms have long been implicated in the construction of stromatolites. Yet, establishing a microbial role in modern stromatolite growth via molecular analysis is not always straightforward because DNA in stromatolites can have multiple origins. For example, the genomic material could represent the microbes responsible for the construction of the stromatolite (i.e., "builders"), microbes that inhabited the structure after it was built (i.e., "tenants"), or microbes/organic matter that were passively incorporated after construction from the water column or later diagenetic fluids (i.e., "squatters"). Disentangling the role of micro-organisms in stromatolite construction, already difficult in modern systems, becomes more difficult as organic signatures degrade, and their context is obscured. To evaluate our ability to accurately decipher the role of micro-organisms in stromatolite formation in geologically recent settings, 16/18S SSU rRNA gene sequences were analyzed from three systems where the context of growth was well understood: (a) an actively growing stromatolite from a silicic hot spring in Yellowstone National Park, Wyoming, where the construction of the structure is controlled by cyanobacteria; (b) a mixed carbonate and silica precipitate from Little Hot Creek, a hot spring in the Long Valley Caldera of California that has both abiogenic and biogenic components to accretion; and (c) a near-modern lacustrine carbonate stromatolite from Walker Lake, Nevada that is likely abiogenic. In all cases, the largest percentage of recovered DNA sequences, especially when focused on the deeper portions of the structures, belonged to either the tenant or squatter communities, not the actual builders. Once removed from their environmental context, correct interpretation of biology's role in stromatolite morphogenesis was difficult. Because high-throughput genomic analysis may easily lead to incorrect assumptions even in these modern and near-modern structures, caution must be exercised when interpreting micro-organismal involvement in the construction of accretionary structures throughout the rock record.

Linking physics and spatial statistics: A new family of Boltzmann-Gibbs random fields

We investigate a connection between spatial statistics and statistical physics to obtain new covariance functions with direct physical interpretation for spatial random fields. These covariance functions are based on the exponential Boltzmann-Gibbs representation and use an energy functional to represent interactions between the values of the random field at different points in space. This formulation results in closed-form generalized covariance functions, which display infinite variance in Euclidean spaces of dimension larger than one. We propose regularization schemes in real and reciprocal (spectral) space that lead to well-behaved covariance structures. The real-space regularization parameter allows a continuous interpolation between the Boltzmann-Gibbs covariance and the exponential covariance. We also propose discretized approximations on regular grids, and we show that they represent reparametrized versions of the well-known Besag and Leroux lattice models. We then discuss parameter estimation and spatial prediction for the regularized Boltzmann-Gibbs covariance model in two dimensions. We recommend using the pairwise difference likelihood that combines satisfactory estimation performance and good scalability with many observation points. The predictive performance of the regularized covariance function is assessed by means of cross-validation statistics. Irregularly-spaced samples from the Walker Lake dataset are used, and spatial prediction is conducted by means of ordinary kriging. The regularized Boltzmann-Gibbs covariance yields improved predictive performance compared to the exponential covariance model.

Combining underwater and terrestrial research approaches in the Great Basin Desert, Walker Lake, Nevada

Underwater and inundated prehistoric archaeology is usually celebrated because it highlights unique cultural behaviors (e.g., Windover and Old World bogs), preserves organic materials exceptionally well (e.g., Little Salt Springs and Bouldnor Cliff), or identifies early human presence (e.g., Page Ladson and Hoyo Negro). However, as research has progressed, it is increasingly clear that underwater archaeology is an essential tool for understanding how humans adapt to changing landscapes and the water/land boundaries around them. When appropriate, archaeologists should consider the dynamics of changing water levels, where nearby human occupations may preserve, and whether terrestrial or inundated landforms may help answer research questions. In the Great Basin USA, Nevada’s Walker Lake is an ideal location for applying this approach. As a lake that has undergone repeated rise and fall over the last 15,000 years, research on human behavior and regional adaptations must consider landforms that have been subject to inundation and are now above and/or below the current waterline. This paper discusses identification and analyses of sites around Walker Lake, investigations revealing intact buried terrestrial landforms under the lake, and how this research provides an improved picture of human behavior and landscape adaptations in the Western Great Basin.

Developing a conceptual model and power capacity estimates for a low-temperature geothermal prospect with two chemically and thermally distinct reservoir compartments, Hawthorne, Nevada, USA

The Hawthorne area in the Basin and Range province in Nevada in the western USA has been the focus of geothermal investigations for over 40 years, with initial discovery of blind resources via anomalously-warm water wells. Subsequent studies and drilling of temperature gradient holes and geothermal wells identified three separate blind geothermal prospects in the Hawthorne part of the Walker Lake basin. In this study, we conducted a detailed review of all existing geoscience data acquired at the site to date to develop a quantitative estimate of geothermal resource potential for one of the Hawthorne geothermal prospects (prospect A — along the southwest side of the basin). This included review of substantial well data from water wells and geothermal exploration wells (downhole temperature logs, lithology, water chemistry, borehole televiewer, and alteration mineralogy), detailed geological and structural mapping information, geophysical data (gravity, magnetic, and seismic reflection), 2-meter temperature data, and an existing 3D geological model of the basin. We find that the thermal anomalies associated with prospect A reflect the influence of two geothermal fluids in close proximity that are chemically-distinct, with different temperatures and spatial extent (lateral and vertical). One fluid represents a deeper resource, hosted in altered, fractured Mesozoic granitic basement along a segment of the Wassuk Range-front fault system, and characterized by equilibrated, alkali-chloride fluids, with ∼4000 ppm total dissolved solids (TDS) and a maximum measured temperature of ∼115 °C at ∼1500 m depth. A second fluid is hosted in Neogene basinal sediments at <400 m depth, with maximum measured temperatures of ∼100 °C, TDS of ∼1000 ppm, and a sodium-sulfate fluid chemistry. The outflow of this shallow resource can be tracked down gradient into the basin using well temperature data, which map a vertically-constrained plume that cools with distance from the inferred upflow location. The data suggest that the deeper resource is conductively transferring heat to the shallow resource, and structural and/or stratigraphic compartmentalization is preventing direct interaction and fluid mixing. Through our development of a new conceptual model of prospect A (with P10, P50, and P90 scenarios), and application of the power density method, we estimate the deep and shallow systems may have resource potential of 7 MWe (P50) and 1.6 MWe (P50) respectively.

Constrained Kriging: An Alternative to Predict Global Recoverable Resources

In most NI-43-101 resource assessment reports the prediction of global in situ resources is performed by either inverse distance weighting, ordinary kriging (OK) or uniform conditioning (UC). These methods have known drawbacks: OK estimates are oversmoothed, and UC necessitates an additional step to localize resources within panels. An alternative, named constrained kriging (CK), enables to circumvent the smoothing issue of OK by imposing the desired theoretical variance to the interpolated variable. CK is not used in NI-43-101 reports, possibly due to a lack of real application examples and little detailed study of its properties. This paper seeks to fill the gap by comparing the prediction performance for global resources of OK, UC and CK on a synthetic lognormal dataset and two real datasets, the Walker Lake and a gold deposit. Results indicate that CK, although being slightly less precise than OK, provides better predictions of grade-tonnage curves than OK and predictions comparable to UC, a remarkable achievement considering that UC is a widespread nonlinear method specifically designed to predict recovery functions. CK is also shown to provide resource estimates more robust than UC with respect to the variogram model specification. Hence, CK appears as a valuable tool allowing simultaneously to localize resources and easily account for change of support in resources estimation.

Integrating data-to-data correlation into inverse distance weighting

As a typical spatial interpolation method with high efficiency and simplicity, inverse distance weighting (IDW) is almost a standard estimator in numerous fields such as geosciences and environmental science. However, it ignores the data-to-data correlation, which directly leads to unfavorable estimates with irregularly distributed samples. To address this issue, we propose a novel approach, termed dual IDW (DIDW). First, the average distance from one sample to others is employed to measure the data redundancy. Second, we impose an additional exponent on the average distance to make its importance adjustable. Last, this data-to-data distance is incorporated into the traditional IDW to account for the spatial configuration of neighborhoods in the interpolation. Consequently, DIDW flexibly takes both data-to-unknown and data-to-data distances into account. Only those samples that are close to the estimated location but apart from other sampled data would be assigned with large estimation weights. Details of its application and the validity are illustrated using a case study based on the public Walker Lake dataset. Our results indicate that the developed methods not only improve the interpolation accuracy significantly compared with the traditional IDW, but also slightly outperform ordinary kriging in the case where the sample dataset is too small to capture an appropriate spatial continuity, demonstrating that DIDW is valuable to be applied in a broader context.

Calibration of random fields by FFTMA-SA

A new algorithm is presented aiming to generate realizations calibrated to desired or observed field response functions. The Fast Fourier Transform Moving Average - simulated annealing algorithm (FFTMA-SA) combines the FFTMA method of simulation and the simulated annealing (SA) method for calibration. SA is performed on the uncorrelated random numbers used within the FFTMA algorithm, keeping by construction the field covariance function unchanged. Hard data exact conditioning by kriging is easily introduced into the algorithm main loop. An interesting advantage of FFTMA-SA is the capability to perturb the field locally or globally, simultaneously on any desired number of points. We therefore introduce a decreasing schedule on the number of points to perturb mimicking the cooling schedule of the temperature parameter in SA. Two cases studies are presented. The first one is a spatially asymmetric synthetic field where FFTMA-SA is shown to better reproduce the spatial asymmetry than calibrated realizations obtained either by classical SA or by FFTMA combined with gradual deformation. The second example is the Walker Lake data where regularized row and columns facies proportions are imposed. It is shown that few iterations (100) of FFTMA-SA are enough to reproduce the main characteristics of the proportion curves. Increasing the number of iterations only reduces rather uniformly the variability of realization proportions. The same data is used to illustrate the local calibration capability of the method with a local data assimilation example. The proposed algorithm offers a simple and flexible tool for calibration. It is easily adaptable for any moving average method of simulation.

Late Holocene paleohydrology of Walker Lake and the Carson Sink in the western Great Basin, Nevada, USA

AbstractThe late Holocene histories of Walker Lake and the Carson Sink were reconstructed by synthesizing existing data in both basins along with new age constraints from key sites, supplemented with paleohydrologic modeling. The repeated diversions of the Walker River to the Carson Sink and then back to Walker Lake caused Walker Lake–level fluctuations spanning ± 50 m. Low lake levels at about 1000, 750, and 300 cal yr BP are time correlative to the ages of fluvial deposits along the Walker River paleochannel, when flow was directed toward the Carson Sink. The timing and duration of large lakes in the Carson Sink were further refined using moisture-sensitive tree-ring chronologies. The largest lakes required a fourfold to fivefold increase in discharge spanning decades. Addition of Walker River flow to the Carson Sink by itself is inadequate to account for the required discharge. Instead, increases in the runoff coefficient and larger areas of the drainage basin contributing surface runoff may explain the enhanced discharge required to create these large lakes.

Field parametric geostatistics - An alternative to tackle gold grade estimations

Abstract High anomalous grades are very common in gold deposits, whose presence requires careful treatment to prevent overestimation of metal content. Mineral resource analysts have worked on the estimation of several gold deposits, and none of the classical methods were able to avoid manual interventions, such as cutting high grades for local estimation or using more information beyond the data for the variogram inference. The Field Parametric Geostatistics (FPG) is presented as an alternative for the application of linear kriging methods to estimate highly skewed distributions, proposing a mathematical model which incorporates the grades and its representativeness into a new variable, reducing the influence of high grades without empirical manual interventions. In this article, the mathematical formulation of the FPG theory is presented, as well as its application in datasets with outliers and high skewed distributions: the Walker Lake dataset and the Amapari gold deposit. The results are compared to results obtained by the application of standard techniques, demonstrating that FPG is a feasible alternative to estimate local grades and local reserves for highly skewed variables.

A New Water Law Vista: Rooting the Public Trust Doctrine in the Courts

Courts largely view the public trust doctrine as limited by state legislative and executive policy. According to this widespread theory, states may be required to hold in trust a handful of historically-big waterbodies (referred to as “navigable” waters) for certain uses like commerce, but beyond that, states are free to dispose of water without considering the public’s interests.36 So there is no requirement that states consider, for example, the public’s interest in conserving Walker Lake, a lake much older that the state of Nevada itself. And not only can the public not meaningfully challenge a state’s legislative or executive decisions in state courts—but they can’t challenge the state’s abdication of the public trust in federal court, either. Because the scope of the trust is supposedly a state-law matter. Courts and litigants have struggled to craft a theory that will allow the state’s trust duties to extend to more water and more uses, and perhaps most importantly, enforceable in both state and federal courts. I suggest such a theory here. In short, this article explains why we should view the public trust doctrine as reflecting very basic principles of limited state authority over water. This limitation prevents states from seriously infringing on the public’s interest in all flowing water. In other words: when states (and occasionally the federal government) abdicate their public trust duties, they are permitting an infringement on the public’s fundamental right to water—a violation of due process and a violation of the states’ sovereign authority. This theoretical framework allows federal courts to review a state’s decision to forego its trust duties, even when it needs to go beyond those historical, navigable waters. After all, viewed this way, enforcing the public trust is a remedy to protect the public’s interest in natural waters generally. Not only should litigants be able to argue for an expansion of trust duties in state courts under state constitutions, they should also be able to argue for this expansion in federal courts under the U.S. Constitution. Interpreting which waters and uses are protected by the trust is, in effect, interpreting the extent of sovereign authority over water. That is a job uniquely for the judiciary. The court doors should be flung wide open in even the most restrictive of states, allowing citizens to challenge legislative and administrative decisions about water allocation. Courts will be empowered to expand the public trust even in the face of legislative and administrative obstinance.