Management of groundwater as a common pool resource relies heavily on an institutional design that is fitted to the aquifers to be managed and is scaled to provide efficient and effective governance. Texas has committed to a decentralized system of groundwater management through Groundwater Conservation Districts (GCDs) that offers a high level of local control and area-specific adaptability. However, increasing pressures on the state’s groundwater resources coupled with a strong local aversion to outsider interference has resulted in a proliferation of small single-county GCDs that are neither well fitted to the aquifer systems nor sufficiently scaled to be efficient or effective. In recognition of these challenges, the persistent response has been a slow transition towards larger-scale management. Although a full transition to centralization via state control is not likely to be politically feasible, it would also be limited in its effectiveness, recognizing the wide diversity of climate conditions, water use patterns, growth projections, and aquifer characteristics that exist across the state. Regionalization is offered as a policy proposal for an institutional arrangement and scale of groundwater governance that provides a balance between centralization and decentralization, using institutions that are better fitted to the aquifer systems and appropriately scaled to provide sufficient funding and resources. The merits and logic of regionalized groundwater management have been recognized as demonstrated by the establishment of the joint regional-planning process within aquifer-based Groundwater Management Areas (GMAs), using GCD representatives as the de facto regional groundwater planners. However, the new unfunded mandates for which the already underfunded GCDs are now responsible and the extraordinary planning process complexity that has developed may prove to be unworkable. This realization compels consideration of management through regional authorities designed using the ready-made framework of the GMAs and principles gleaned from successful models of regionalization from other states and within Texas. Such regional authorities, if provided with sufficient resources and authority, would respect the logic of fit and scale and would be better equipped to address the current and future groundwater management challenges in Texas. / text

Understanding water balances is essential for sustainable water resource management, especially in semi-arid basement complex areas where there are large demands for water supplies, but the complex hydrogeological conditions limit groundwater development. This research presents an approach for water balance estimation based on the conceptual and computational modelling of six major landscape unit’s which have been classified on the basis of their differing hydrological responses. Detailed conceptual models of the hydrological processes operating in each of the different landscapes in a catchment and the processes that control water movement between the different landscapes are developed based on data analysis, fieldwork and literature. Two computational models (the WaSim soil water balance model and a new water balance model for bare rock) are used to estimate the daily water balance of each of the landscape units taking cognisance of their interconnectivity which includes runoff becoming run-on. Water balance simulations were run for the individual landscapes using input data from the semi-arid Sokoto Basin in Northwest Nigeria, and outputs for representative wet and dry years are used to demonstrate the reliability of model responses. The individual landscapes outputs were subsequently integrated, taking account of their area weighted contributions, to give a catchment-scale water balance which compares favourably with the observed river discharge at Fokku. The catchment water balance results reveal that AET accounts for the largest loss in the catchment at 72 % of the average rainfall for 37 years. This is followed by the groundwater flow to rivers, then runoff to rivers, representing 16% and 11 % of the average rainfall. This research has provided valuable insights into hydrological behaviour of the basement complex system and the effect of landscape variability on the water balance of these areas. The research suggested a rational approach to groundwater resource management in the basement complex areas that takes cognizance of the hydrological behaviour of different landscape units, focussing on areas with deep weathered material within the catchment identified in this research. The research specifically stresses the need to apply methods of water conservation during excess rainfall for future use in the dry season.

This dissertation in environmental history is concerned with human landscapes of groundwater extraction. Using temporal and spatial comparison, it examines the role of groundwater tunnel-wells and human understandings of groundwater availability in the Western Desert of Egypt; the Balearic Islands of Spain; and Iran. In an Epilogue and final chapter, it examines conceptions of 20th-century expertise for environmental knowledge and economic development.

Rapid population growth and climate variability have been posing pressure on groundwater management, especially in regions dominated by irrigation agriculture. Effective management practices require a better understanding of groundwater dynamics and its contributing factors, such as recharge, groundwater-surface water interactions, soil and unsaturated zone characteristics. Although groundwater models can provide valuable insights into these questions, these models are often nonexistent or cost prohibitive.

This dissertation considers modeling groundwater flow under imprecisely known parameters and managing a plume of contaminant. A new approach has been developed to study the effects of parameters uncertainty on the dependent variable, here the head. The proposed approach is developed based on fuzzy set theory combined with interval analysis. The kind of uncertainty modeled here is the imprecision associated with model parameters as a result of machine or human imprecision or lack of information. In this technique each parameter is described by a membership function. The fuzzy inputs into the model are in the form of intervals so are the outputs. The resulting head interval represents the change in the output due to interval inputs of model parameters. The proposed technique is illustrated using a two dimensional flow problem solved with a finite element technique. Three different cases are studied: homogeneous, mildly heterogeneous and highly heterogeneous transmissivity field. The groundwater flow problem analysis requires interval input values for the parameters, the output may be presented in terms of mean value, upper and lower bounds of the hydraulic head. The width of the resulting head interval can be used as a measure of uncertainty due to imprecise inputs. The degree of uncertainty associated with the predicted hydraulic head is found to increase as the width of the input parameters interval increases. Compared to Monte Carlo simulation approach, the proposed technique requires less computer storage and CPU time, however at this stage autocorrelation and crosscorolation are not configured in the presented formulation. In the plume containment problem two formulations are presented using the hydraulic gradient technique to control the movement of the contaminants. The first one is based on multiobjective analysis and the second, on fuzzy set theory. Multiobjective analysis yields a set of alternative strategies each of which satisfies the multiple objectives to a certain degree. Three different techniques have been used to choose a compromise strategy. Although they follow different principles, the same preferred strategies are selected. It is also noticed that rapid restoration results in a large pumping volumes and high costs. Using a fuzzy formulation for plume containment yields the optimum pumping rates and locations in addition to the membership function at each pumping location. The resulting membership functions at these pumping locations can be used to study the sensitivity of each location to a change in objective function and constraints bounds. Overall, both the fuzzy and multiobjective methodologies, presented in this dissertation, provide new and encouraging approaches to groundwater quality management.

Master of Agribusiness / Department of Agricultural Economics / Bill B. Golden / While Kansas, and specifically western Kansas, are known by many to be the backbone of agriculture in our nation, much of that productivity has been built on the heels of the invention and efficiency of irrigation technology. Unfortunately, recharge and replenishment of the High Plains - Ogallala Aquifer has not kept pace with the demands of agricultural production, and current indications state that without the implementation of conservation or management practices that the aquifer in Kansas could be depleted by 2060 (Steward, et al. 2013). The producers of Kansas are committed to long-term solutions to preserve their way of life, espouse their commitment to natural resources and the environment, and ensure the viability of their operations for years to come. This study analyzed the economic impact of a proposed Local Enhanced Management Area (LEMA) for Groundwater Management District ¬(GMD) #4. While there currently is a LEMA in a portion of GMD #4 known as the Sheridan 6 LEMA, the board of GMD #4 has initiated the process to institute a district-wide LEMA that would affect a large portion of the 10-county area of the groundwater management district (Cheyenne, Rawlins, Decatur, Sherman, Thomas, Sheridan, Graham, Wallace, Logan, and Gove Counties). To complete the analysis for the proposed policy change, multiple scenarios were derived using the IMPLAN software. The first model serves as the baseline scenario and provides status quo information on the current irrigated cropping economics of GMD #4. The second scenario assumes that a district-wide LEMA would require a 25% reduction in groundwater use, compared to current irrigation practices. To achieve this reduction in groundwater use, irrigated acreage was reduced by 25% and transitioned to dryland production. For the third and final scenario, an optimal irrigated crop-mix ratio is determined based on the current shift in production as reported by the producers in the Sheridan 6 LEMA. While this scenario does not reduce irrigated acres, it shows the economic gains that can be captured by using less water-intensive crops as part of the crop-mix ratio. The reduction in irrigation is also imbedded in that the acreage in which production is shifted away from is more water intensive towards acreage that is less water-intensive. Due to a reduction in groundwater use for irrigation, the study determined that there is a negative economic impact in relation to employment and total output in the GMD #4 area. There are 173 less individuals employed from the 25% reduction in groundwater use. Additionally, direct output is reduced by $44.6 million and total output is reduced by $60.0 million. This equates to a $194.49 reduction per acre on a per-acre basis. The study further showed that the economic impact could be lessened by the use of a crop-mix shift as evidenced in the current Sheridan 6 LEMA. The assessment of a crop-mix shift decreased the loss of direct output by $12.0 million to $265.0 million and total output by $16.5 million to $357.1 million. On a per-acre basis, this is a reduction of $140.97, or mitigation of $53.52 in loss per acre due to the use of an optimal crop-mix shift. While agricultural production is highly dependent on many factors, it can be universally agreed that the landscape of agriculture would be different if water was not an available resource. It is the hope that this research will provide a starting point for the producers of GMD #4 to have a conversation about the economic costs associated with the implementation of a LEMA, as well as discuss other options and opportunities to make educated, well-informed decisions that are impactful both now and for generations to come.

Philosophiae Doctor - PhD / Governance is essentially the process whereby organisations or networks of organisations exercise their authority. It describes how a body with authority makes or does not make decisions, and how it implements - or does not implement - those decisions. 'Good' groundwater governance can then be defined by how fair the decision-making process is, and how effective the implementation process is. Groundwater governance in South Africa is increasingly being categorized as ineffective. The purpose of this thesis is to explore ways to improve groundwater governance in South Africa. Initial reviews of international studies of groundwater governance did not find any processes that could be directly imported into the South African governance landscape for testing. The global consensus was that there were no blueprints for improving groundwater governance, and that each case should be treated as unique. Therefore the thesis had to change from its initial aim of finding firm rules that could be tested in the South African context, to a revised aim of formulating tentative heuristics, rules, strategies and hypotheses that might be useful for further work in the South African context.An exploratory, inductive-based, loosely structured methodology was therefore employed rather than a more formal, deductive-based testing of hypotheses. In short, the objective of this thesis was concerned with formulating hypotheses rather than testing them.The novel, general, contribution made by this thesis is to synthesize global groundwater governance literature with the specific aim of improving groundwater governance in a specific country. While reviews of global literature do exist, they have thus far only been used to make generic recommendations, and have not been specifically applied to a country. Conversely, while attempts to improve groundwater governance for specific regions and countries do exist, these attempts have largely done so without synthesizing existing global knowledge. Indeed, the emphasis on national, regional and local studies has principally been to understand the factors at work affecting groundwater governance, rather than to improve governance.

Groundwater accounts for approximately 99% of the available freshwater on Earth, and is an important resource for irrigation, potable water, and domestic use in the United States. However, the overuse of groundwater has led to aquifer depletion in several basins across the USA, resulting in storage reduction, contamination, salt water intrusion, and depletion of surface waters. To properly manage groundwater for the future, there is a need for well-informed Groundwater Management Plans (GWMPs) in order to prevent further depletion and erosion of the resource. Previous studies have focused on groundwater management relative to groundwater laws, regulations, and institutional arrangements. This study analyzed GWMPs to better understand how allowable yields are set, how interconnected groundwater conditions are addressed, and how groundwater systems are managed when information on the system is lacking through planning. The findings of this study delineate how groundwater management goals are set across the United States and provides recommendations to inform future GWMPs.

<p>In order to find effective measures that meet the requirements for proper groundwater quality and quantity management, there is a need to develop a Decision Support System (DSS) and a suitable modelling tool. Central components of a DSS for groundwater management are thought to be models for surface- and groundwater flow and solute transport. The most feasible approach seems to be integration of available mathematical models, and development of a strategy for evaluation of the uncertainty propagation through these models. The physically distributed hydrological model ECOMAG has been integrated with the groundwater model MODFLOW to form a new integrated watershed modelling system - ECOFLOW. The modelling system ECOFLOW has been developed and embedded in Arc View. The multiple-scale modelling principle, combines a more detailed representation of the groundwater flow conditions with lumped watershed modelling, characterised by simplicity in model use, and a minimised number of model parameters. A Bayesian statistical downscaling procedure has also been developed and implemented in the model. This algorithm implies downscaling of the parameters used in the model, and leads to decreasing of the uncertainty level in the modelling results. The integrated model ECOFLOW has been applied to the Vemmenhög catchment, in Southern Sweden, and the Örsundaån catchment, in central Sweden. The applications demonstrated that the model is capable of simulating, with reasonable accuracy, the hydrological processes within both the agriculturally dominated watershed (Vemmenhög) and the forest dominated catchment area (Örsundaån). The results show that the ECOFLOW model adequately predicts the stream and groundwater flow distribution in these watersheds, and that the model can be used as a possible tool for simulation of surface– and groundwater processes on both local and regional scales. A chemical module ECOMAG-N has been created and tested on the Vemmenhög watershed with a highly dense drainage system and intensive fertilisation practises. The chemical module appeared to provide reliable estimates of spatial nitrate loads in the watershed. The observed and simulated nitrogen concentration values were found to be in close agreement at most of the reference points. The proposed future research includes further development of this model for contaminant transport in the surface- and ground water for point and non-point source contamination modelling. Further development of the model will be oriented towards integration of the ECOFLOW model system into a planned Decision Support System.</p>

<p>The aim of this investigation was to provide a framework or strategy for prioritising and implementing regional groundwater monitoring in the Olifants-Doorn Water Management (WMA) area. The general approach was to attempt to reconcile monitoring requirements with existing resources, while investigating the hypothesis that regional monitoring should focus on resource status monitoring. Groundwater science needs to focus on clarifying the sustainability options available to the stakeholders, and monitoring the chosen option. This can best be done by adopting an adaptive management approach to both the management of the groundwater resources, and the management of the monitoring programme.</p>