ABSTRACT The Edwards Aquifer Authority (EAA) was established in 1996 after lawsuits that were filed for the protection of endangered species in Comal and San Marcos Springs revealed the need for aquifer management. Several events set the stage for water management in Texas and the creation of the EAA. The EAA succeeded the Edwards Underground Water District, which was formed after the 1951–1956 drought of record. The EAA was eventually granted regulatory responsibilities, including issuing permits for wells, setting limits on groundwater pumpage, and development of a habitat conservation plan to protect endangered species.

ABSTRACT Aquifer storage and recovery (ASR) is a proven water-supply strategy that uses an aquifer to store surplus water that will be available for later use when that stored water is needed. Although only three ASR systems are currently operating in Texas, recent incentives from the state, along with changes in regulatory framework, have helped to encourage consideration of ASR as a viable water-supply strategy. The changes in Texas law primarily reduced the power of groundwater conservation districts to regulate ASR, and they put the majority of the role of project authorization in the hands of the Texas Commission on Environmental Quality. Two Edwards-named aquifers in Texas were considered in this work: the Edwards-Trinity (Plateau) and the Edwards (Balcones Fault Zone) Aquifers. Both of the aquifers have areas that appear to be suitable, from a hydrogeologic standpoint, for ASR. The Edwards hydrostratigraphic unit of the Edwards-Trinity (Plateau) Aquifer has generally good productivity and water quality. However, in some locations, the high natural gradient combined with low porosity may increase the design challenge due to bubble drift. These same characteristics exist in many areas of the freshwater portion of the Edwards (Balcones Fault Zones) Aquifer, although its high productivity makes for very attractive per-well recharge and recover rates. The lower natural gradient (and thus smaller potential for bubble drift) in the brackish portion of the Edwards Aquifer may make it a good candidate in areas where productivity is sufficient.

Abstract Pumping tests carried out in three highly tectonized Mediterranean areas, which share similar climate conditions, were used to characterize hard-rock aquifers and examine the issue of the sustainable yield of wells. On the basis of the identified drawdown trends and hydraulic parameters, pumping scenarios were simulated through different methods. The results show that the long-term trend in the drawdown and the initial thickness of the aquifer constrain the sustainable yield of a well. In the worst cases examined, namely those related to an aquifer with a barrier boundary and a delayed response of the aquifer, the sustainable well yield is 1–2 L s −1 . These well discharge values are significant when compared with those found in other regions of the world, and may be related to the dense network of the discontinuities which characterizes the sites.

Abstract Karst science is beginning to recognize and understand better the interaction between conduits and the fractures and/or pore spaces within the aquifer. The relationship has important significance in relation to the understanding of contaminant transport, resource management and dewatering practices. This study presents the results of a dye trace carried out to investigate the link between the aquifer and conduits near a large dewatered quarry in the Mendip Hills in Somerset, England. At the point of undertaking the study, there were no records of the quarry directly intercepting any conduits but water from the conduit(s) is known to be drawn into the quarry. During the study, water from the conduits was observed to be lost to and gained from the fractures in different places in the aquifer. This complexity highlights the dependence of conduit flow on water levels in the aquifer and the sensitivity of groundwater in karstified aquifers to contamination.

Groundwater resources in Haiti are considered abundant, with greater than 2 billion cubic meters per year (2 × 10 9 m 3 /yr) of renewable resources and 56 billion cubic meters of reserves. However, groundwater is not available everywhere and many aquifers are often low yielding, discontinuous, or are at risk from saltwater intrusion, overexploitation, reduced recharge, and contamination. Economic development, population growth, and climate change are factors that will increase stress on groundwater resources. Sector leadership, capacity building mechanisms, integrated water policy, and a clear regulatory framework are urgently needed to manage, regulate, and protect Haiti’s groundwater resources to achieve long-term security. Accomplishing this requires technical support and practical references that summarize the groundwater resources and their vulnerabilities, complexities, and opportunities. This chapter includes a summary of knowledge, information, and experience to aid the development and management of Haiti’s groundwater resources, as well as provides an overview of its complex hydrogeology. Five broad hydrogeological environments are differentiated: (1) Unconsolidated alluvium accounts for 26% of Haiti’s land area—it includes a large portion of the country’s groundwater reserves and is the most exploited for irrigation, industry, and potable water; (2) interior sedimentary units account for 32% of Haiti’s land area and include up to 25% of the country’s groundwater reserves—springs from carbonate aquifers are significant sources of water supply throughout the country; (3) reef carbonate accounts for 6% of Haiti’s land area, with locally available coastal karst aquifer systems serving some of the most rural, driest, and impoverished areas of Haiti; (4) semiconsolidated units account for 21% of Haiti’s land area—their low groundwater potential limits rural and urban water use throughout the country; and (5) igneous bedrock accounts for 15% of Haiti’s land area—its discontinuous groundwater reserves are an important source of water in rural and mountainous areas.

Groundwater is the source of drinking water for ~1.4 million people in the Coastal Plain Province of Maryland (USA). In addition, groundwater is essential for commercial, industrial, and agricultural uses. Approximately 0.757 × 10 9 L d ‒1 (200 million gallons/d) were withdrawn in 2010. As a result of decades of withdrawals from the coastal plain confined aquifers, groundwater levels have declined by as much as 70 m (230 ft) from estimated prepumping levels. Other issues posing challenges to long-term groundwater sustainability include degraded water quality from both man-made and natural sources, reduced stream base flow, land subsidence, and changing recharge patterns (drought) caused by climate change. In Maryland, groundwater supply is managed primarily by the Maryland Department of the Environment, which seeks to balance reasonable use of the resource with long-term sustainability. The chief goal of groundwater management in Maryland is to ensure safe and adequate supplies for all current and future users through the implementation of appropriate usage, planning, and conservation policies. To assist in that effort, the geographic information system (GIS)–based Maryland Coastal Plain Aquifer Information System was developed as a tool to help water managers access and visualize groundwater data for use in the evaluation of groundwater allocation and use permits. The system, contained within an ESRI ArcMap desktop environment, includes both interpreted and basic data for 16 aquifers and 14 confining units. Data map layers include aquifer and confining unit layer surfaces, aquifer extents, borehole information, hydraulic properties, time-series groundwater-level data, well records, and geophysical and lithologic logs. The aquifer and confining unit layer surfaces were generated specifically for the GIS system. The system also contains select groundwater-quality data and map layers that quantify groundwater and surface-water withdrawals. The aquifer information system can serve as a pre- and postprocessing environment for groundwater-flow models for use in water-supply planning, development, and management. The system also can be expanded to include features that evaluate constraints to groundwater development, such as insufficient available drawdown, degraded groundwater quality, insufficient aquifer yields, and well-field interference. Ultimately, the aquifer information system is intended to function as an interactive Web-based utility that provides a broad array of information related to groundwater resources in Maryland’s coastal plain to a wide-ranging audience, including well drillers, consultants, academia, and the general public.