Safe Yield Research Articles

Predictive analysis of groundwater balance and assessment of safe yield using a probabilistic groundwater model for the Dead Sea Basin

Predictive analysis of groundwater balance and assessment of safe yield using a probabilistic groundwater model for the Dead Sea Basin

Ecosystem-based management approaches for watershed conservation and geosustainability

When contributors' goals and legislative and political structures vary, as they often do in the case of worldwide fish populations, it becomes more challenging to implement ethical fishing tactics. Canada, the United States, and Mexico all fish from Pacific regions anchovies in the California Modern. Climate-driven numbers and geographic dynamics may pollute the waters of collaborative aquaculture and lead to overloading. This research expands upon prior works using a game theoretic model of Tran's boundary sardine fisheries in different climatic conditions to account for ecological links. More significant economic advantages accrue from cooperation fishing tactics that consider the mackerel's role as feed for other species in the natural system, as opposed to plans that merely take note of the worth of mackerel harvests to a particular fishing nation. The maximum environmental benefit is obtained at a fishery rate for sardines barely less than the sardine Fishery Management Safe Yield. Ecological-based control of fisheries can increase sustainability and profits, but only if investors and policy makers consider the ecology in business-applicable models. Understanding and adapting to the fast alterations in habitat distributions due to climate change and designing ways to achieve viable and lucrative fishery amidst altering environments will necessitate an increased emphasis on ecosystem-based governance.

Safe Yield of Groundwater Utilization for Domestic, Livestock and Hotels Requirement as An Anticipation of Sea Water Intrusion in The Coastal of Batang Regency

As a result of the groundwater utilization which exceeds its safe yield, the phenomenon of seawater intrusion is often found in some coastal areas. For this reason, the utilization of groundwater must not exceed its safe yield. This study aims to calculate the availability of groundwater and its safe yield and evaluate its utilization which does not exceed the safe yield. To achieve this purposes, groundwater availability is calculated using the static method by multiplying the area by the thickness of the aquifer and the specific yield. Utilization of groundwater for domestic, livestock and hotel requirement is carried out by multiplying the water demand for each of these sectors by the amount. Safe yield is calculated based on area width, groundwater fluctuation and its specific yield. The groundwater resources potential of research area amounted to 648,960,234 m3/year, while the safe yield was 127,702,334 m3/year. Utilization of groundwater for domestic, livestock and hotel requirement is 23,062,023 m3/year, so that the use of groundwater to meet domestic, livestock and hotel reqirement has not endangered the availability of groundwater. However, for Batang District, groundwater utilization has almost reached half of its safe yield.

ВЛИЯНИЕ МЕТЕОРОЛОГИЧЕСКИХ УСЛОВИЙ НА РАСПРОСТРАНЕННОСТЬ СОСУЩИХ ВРЕДИТЕЛЕЙ

The article presents the actual results of observations on the prevalence of sugescent pests in the Rostov region, the dynamics of abundance, population, and the peculiarities of the phenological development of pests on technical varieties, depending on meteorological conditions. It is noted that an air temperature of +14 ... +30 ºC and a relative humidity of 52 % are necessary to maintain viability and fertility. The eggs of the buffalo ceresa leafhopper overwinter in the branches and trunks of trees of woody species, often in young annual shoots. The female ovipositor cuts the bark and lays eggs in two rows of 5-11 eggs. Damage by the buffalo ceresa leafhopper causes a violation of the flow of nutrients to the tops of shoots, weakening and a sharp decrease in their growth. The rose leafhopper gives up to 4 generations during the summer. Damaged leaves turn yellow, photosynthesis processes are disrupted in them, plant nutrition deteriorates, which affects the reduction of economically valuable indicators. The presence of sucking pests increases the risk of spreading viral diseases. Insecticides and phytosanitary monitoring are most effective in fruit-bearing vineyards only in combination with high agricultural techniques of cultivation. In this connection, there is a decrease in yield losses and environmental pollution with chemicals. Therefore, it is necessary to deal with weeds in a timely manner, to carry out maintenance work to ensure good ventilation of grape bushes, to regularly carry out phytosanitary monitoring of the population with sugescent pests and diseases, to carry out row-to-row tillage. Chemical treatments are necessary only if the threshold number of pests is exceeded. The article provides suggestions on how to contain the number of pests at a low level to obtain an environmentally safe grape yield.

Utilizing of aquifer hydraulic parameters to assess the groundwater sustainability in the new reclamation area of Moghra Oasis: Western Desert—Egypt

The sustainability of groundwater aquifers requires evaluating several parameters, the most important of which are hydraulic parameters. Therefore, the essential aim of this research is to develop a management plan for the Moghra aquifer in order to prevent the expanding of water level decline and degradation of groundwater quality due to overexploitation and scarcity of recharge. To achieve this goal, all aquifer hydraulic parameters such as transmissivity, hydraulic conductivity, radius of interference, specific capacity, resulted drawdown, well loss, formation loss, well efficiency, and optimum safe yield had been measured for 40 groundwater wells drilled in the new reclaimed areas of Moghra Oasis. Based on geographic information system (GIS), hydrogeological cross sections and thematic maps for all parameters were created such as aquifer thickness, water table, groundwater flow direction, drawdown and groundwater salinity maps. The results revealed that clay and shale beds separated the three water-bearing formations of the Moghra aquifer. The aquifer-saturated thickness ranged from 30 and 102 m, and the groundwater level was below the mean sea level for all wells (ranges from − 72 to − 26.6 m). The calculated hydraulic parameters based on the analysis of long-duration pumping tests indicated that the studied aquifer has a wide variety of transmissivity (T) between 631 and 3768 m2/day, hydraulic conductivity (K) between 13.4 and 104.6 m/day, radius of influence from 126.3 to 581.3 m and specific capacity between 377.14 and 883.72 m2/day. On the other hand, the evaluation of existing drilled wells performance based on the results of step tests showed that well loss coefficient ranges between 0.0004749 and 0.0676 (h2/m5), formation loss coefficient varies from 3.34 × 10–8 to 4.80 × 10–6 (h/m2), well efficiency (γ) ranged from 50.53 to 98.08%, and optimum safe yield ranged from 40 to 98 (m3/h). Results of aquifer mapping and pumping tests can be more important for solving water scarcity issues, non-polluting water issues, health issues, and source of fresh water on the surface of the earth. The characterization of aquifer parameters in the study area, however, should be a significant component in the scientific planning and sustainability of groundwater.

Understanding the exchange process between ground and surface water using mini drive point piezometer and mathematical models to identify suitable managed aquifer recharge sites.

In the current study, subsurface characteristics within the complex formation of the Shilabati basin system of West Bengal, India, extending over an area of 3888 km2, have been estimated using a cost-effective piezometer and MIKE FEFLOW package based on a steady-state numerical model. Pore size and fine particle content of streambeds are affected by two opposing flow contraptions. Such opposite flow conditions are likely to affect the hydraulic conductivity of the streambed. However, analogies of the hydraulic conductivity (Kh) of streambeds for losing and gaining streams have not been well documented in the recent past. The Kh value from the piezometer has been highest at the Dakshin Pairachali site (6.765 m/day), with the stream gaining water from the discharge of the local aquifer. Analysis of the stream-aquifer interaction using the FEFLOW model has allowed us to understand the groundwater water head of the basin ranging from 160.33 to 0.32 m.a.s.l (meters above sea level). The present study also constitutes the first attempt for the identification of suitable sites for the implementation of managed aquifer recharge (MAR) technology in West Bengal, India, to manage extreme drought events. The suitable sites have been identified by means of three fuzzy multi-criteria decision analysis based on nine criteria: river discharge, moisture content, porosity, drainage type, rainfall, land use type, geology, aquifer material, and hydraulic conductivity. To design a radial collector well and infiltration gallery for the selected site in an anisotropic, homogeneous, unconfined, and semi-infinite aquifer near a fully penetrating stream, a pumping test has been conducted to optimize a safe yield of 12.096 MLD (megaliters per day).

Frost hardiness of almond flower buds during dormancy

Frost hardiness of flower buds of twenty almond genotypes was investigated in five dormancy periods by determining LT50 values after artificial freezing tests. The main aim of our work was modelling the changing of frost hardiness of the observed accessions during dormancy and assessing the potential best frost tolerance of them. The effect of genotype and year had significant impact on frost hardiness of flower buds. The potential frost hardiness of accessions has been characterised by LT50 values of flower buds averaged of the bests of the four years. ‘Sóskút 96/5’ was the most sensitive with -17.16 °C, and ‘Tétényi keményhéjú’ was the most frost hardy with -21.08 °C in averaged of years, but both showed lower and higher frost tolerance as well in different years. Flower buds were most frost-tolerant in December and January but did not achieve the same frost resistance every year. From this, we conclude that temperature plays an important role in the hardening process of them. From the aspect of safe yield, frost hardiness of flower buds is an important trait of cultivars, because Hungary is situated at the northern part of economical almond growing area. Our work contributes to facilitating practical considerations in orchard planning.

Determining safe yield and mapping water level zoning in groundwater resources of the Neishabour Plain

Groundwater is a crucial sources of water supply, especially in arid and semi-arid areas around the world. With uncontrolled withdrawals and limited availability of these resources, it is essential to determine the safe yield of these valuable resources. The Hill method approach was used in this study to determine the safe yield the Neishabour aquifer in Khorasan Razvi province in Iran. The results showed that the safe yield in the Neishabour aquifer is 60% lower than the current pumping amounts during the study period, indicating that further overdrafts could result in the destruction of this aquifer. This highlights the importance of using the Hill method to estimate the permitted exploitation from other aquifers, thus preventing problems caused by over-extraction and maintaining stability of global groundwater levels.

Synergetic Water Demand and Sustainable Supply Strategies in GCC Countries: Data-driven Recommendations

The Gulf Cooperation Council (GCC) countries, characterized with limited water resources and high oil/gas revenues, rely heavily on energy-intensive seawater desalination and non-renewable groundwater abstraction. The need to shift solutions to demand-side practices and sustainable supply alternatives has been long advocated; yet this study is the first to “quantify” the impacts of such solutions on the water management system of Qatar – considered a study case of GCC countries. In this research, a scenario-based approach was utilized to predict the impact of water demand control and wastewater reuse (and the resulting synergies) on consumption of desalinated water, extraction of groundwater resources, and development needs of water and wastewater infrastructure. To this effect, country-specific models for Qatar were developed to project annual household water demand, wastewater generation and residential construction growth, up to year 2050. The outcomes showed that tariff reforms and regulated greywater reuse would reduce the annual household demand for desalinated water by up to 27% and 7%, respectively. Also, intensive reuse of Treated Sewage Effluent (TSE) would reduce 40–80% of total groundwater abstraction for irrigation by 2050. Finally, adopting an integrated water strategy, with combined demand and supply management targets, creates synergies that would: (1) limit groundwater abstraction to rates close to the aquifers safe yield; and (2) delay the need for expansion of the water and wastewater infrastructure by more than a decade. Data-driven recommendations were provided accordingly.

Aquifer Recharge and Overexploitation: TheNeed for a New Storyline.

Aquifer Recharge and Overexploitation: TheNeed for a New Storyline.

A market-based mechanism for long-term groundwater management using remotely sensed data

Groundwater markets improve the agricultural economy by transferring water entitlements from low-efficient users to high-efficient ones to maximize productivity. Aiming at developing an efficient groundwater market, the environmental effects of the market mechanism should be assessed, and a reliable method for monitoring water consumption needs to be employed. Toward this end, this paper proposes three annual smart groundwater market mechanisms to maximize water net benefits, minimize groundwater withdrawal, and precisely measure water consumption in agricultural fields. To guarantee the aquifer's safe yield in each mechanism, a groundwater simulation model (i.e., Groundwater Modeling System (GMS)) is used to control groundwater table drawdown at the end of the planning horizon. In addition, the fields' evapotranspiration (ET) is estimated using Surface Energy Balance Algorithm for Land (SEBAL) and Mapping Evapo Transpiration at high Resolution with Internalized Calibration (METRIC) algorithm to measure the net groundwater consumption during the market. In this regard, we evaluated the algorithms' performances using observed data from a local lysimeter. They are applied to the Nough plain in Iran to assess the effectiveness of the proposed market framework. The findings illustrate their efficiency in recovering approximately 80% (23.33 million cubic meters (MCM)) of groundwater loss due to overexploitation in the study area and increasing the users' annual benefits by 10.6% compared to the non-market condition. In addition, results imply that the METRIC model approximates daily crop ET with a higher accuracy level than the SEBAL model with RMSE, MAE, and Percentage Error of 0.37 mm/day, 0.32 mm/day, and 14.92%, respectively. This research revealed that the proposed market framework is a powerful tool for reallocating water entitlements and increasing water productivity in arid and semi-arid regions.

Analysis of Groundwater Potential in the Coastal Area of Parangtritis using Geoelectrical VES Method

This research was conducted in the coastal area of Parangtritis, Bantul Regency, Special Region of Yogyakarta. This study aims to describe the hydrostratigraphy of aquifers using the Vertical Electrical Sounding (VES) geoelectric method, to calculate the volume of availability and safe yield of groundwater application, and to compare the volume of availability of safe products with the demand for water for domestic and tourism purposes. This study uses a field survey approach and field data analysis. In this study, there were 9 VES measurement points for primary data and 16 VES measurement points from secondary data, five samples of water demand for restaurants, and 74 samples of domestic groundwater needs. The VES point was measured by a purposive random sampling method representing each landform. Hydrostratigraphic analysis and preparation of 2D and 3D cross-sectional models of subsurface lithology were performed on all VES geoelectrical measurement data. The results showed that the aquifer layer is located at varying depths for each landform, with alluvium sand as the constituent material. The most significant potential for groundwater is found in the form of dunes and beach ridges. The second-largest groundwater potential is in fluviomarine landforms, and the most minor is in the alluvial plain. The groundwater availability in each landform is sand dune and beach ridge of 117,776,100 m3; fluviomarine plain (45,422,700) m3; and alluvial plain (25,553,000) m3. Then, the safe yield of groundwater is 3,498,300 m3 in sand dunes and beach ridges, fluviomarine plain (1,566,300 m3), and alluvial plains (580,750 m3). Meanwhile, based on the calculation of the total need for groundwater for domestic and tourism purposes, the availability of safe yield is still in surplus or sufficient for the estimated needs.

How the new fed municipal bond facility capped municipal-treasury yield spreads in the Covid-19 recession

For over two centuries, the municipal (muni) bond market has been a source of systemic risk, which returned early in the Covid-19 downturn when borrowing from securities markets became costly for many private and public entities, and some found it difficult to borrow at all. Indeed, just before the Fed announced its unprecedented intervention into the muni market, spreads of muni over Treasury yields rose in line with the unemployment rate and appeared headed to levels not seen since the Great Depression, when real municipal gross investment plunged 35 percent below 1929 levels. To prevent such a calamity, the Fed created the Municipal Liquidity Facility (MLF) to purchase newly issued, (near) investment-grade state and local government bonds at ratings-based interest rate spreads over the safe OIS benchmark yield. In general, these spreads were initially about 100 basis points above average spreads under more normal market conditions and were later lowered by 50 basis points in August 2020. Despite a modest take-up, our study documents the MLF prevented muni spreads from rising much above those margins (plus a modest 10 basis point fee) and limited the extent to which interest rate spreads could have amplified the impact of the Covid pandemic. To establish the MLF the Fed needed Treasury indemnification against default losses. There were concerns about whether the creation of the MLF could induce moral hazard among borrowers and could undermine the efficiency of the bond market if the facility had lasted too long. Partly for this reason and because the muni market had settled down by yearend 2020, the Treasury terminated the MLF at that time. Future assessments of these downside aspects will help answer the question whether the program's benefits addressed here exceeded its costs.

Alternate reservoir operating policies for Lake Victoria in East Africa: A framework for balancing transboundary and local water demands

AbstractThe reliability and impact of several regulation policies on Lake Victoria in East Africa were investigated using the Water Rights Analysis Package (WRAP). Its reliability is determined by establishing the risk of policies failing to meet water demands. The impacts on the lake are evaluated by assessing the effect of policies for lake levels. Policies are based on (i) the lake's firm and safe water yields and (ii) dam turbine configurations at the lake's outlet. The present study demonstrated the applicability of WRAP in modelling large complex reservoirs and determined that constant release policies with a maximum limit of 1015 m3/s have low risks of failure and improve lake water‐level stability.

Techno-Economic Analysis of Selected PV-BWRO Desalination Plants in the Context of the Water–Energy Nexus for Low–Medium-Income Countries

Jordan was late in adopting seawater and brackish water desalination as a source until the late 1990s and early 2000s. However, ongoing studies are still discussing the technical, economic, and socio-political aspects of brackish water reverse osmosis (BWRO) desalination plants. In this study, the water–energy nexus was considered, in order to highlight the main challenges facing BWRO desalination. We discuss the use of photovoltaic (PV) technology, together with BWRO desalination, as an approach to compensate for ecological, financial, and social challenges in Jordan. For this purpose, the performance of nine existing BWRO desalination plants in the agricultural, domestic, and industrial sectors is assessed. The water performance is assessed based on water consumption, safe yield extraction, plant recovery rate (R, %), and compliance to local and international water quality standards; the Specific Energy Consumption (SEC, kWh/m3) is taken as the main evaluation criterion to assess the energy performance of the BWRO desalination plants; and economic performance is assessed based on the overall cost of water produced per cubic meter (USD/m3). The main environmental component is the brine disposal management practice utilized by each plant. Based on this assessment, the main challenges in BWRO desalination are the unsustainable patterns of water production, mismanaged energy performance, low recovery rates, and improper brine disposal. The challenges in domestic and industrial BWRO desalination, which are completely dependent on the electricity grid, are associated with critical energy and costs losses, as reflected by the high SEC values (in the range of 2.7–5.6 kWh/m3) and high water costs per cubic meter (0.60–1.18 USD/m3). As such, the use of PV solar panels is suggested, in order to reduce the electricity consumption of the assessed BWRO plants. The installation of PV panels resulted in significantly reduced energy costs (by 69–74%) and total costs (by 50–54%), compared with energy costs from the electricity grid, over the lifetime of the assessed BWRO desalination plants.

The Water Budget Myth and Its Recharge Controversy: Linear vs. Nonlinear Models.

The water budget myth, which is the idea that safe pumping must not exceed the initial recharge, gave rise to a controversy about the role of recharge in assessing the sustainability of groundwater development. To refute the concept of safe yield, a simplified water budget equation is used, which equals the total pumping rate to the sum of capture and storage change. Since initial recharge and discharge are canceled out from this equation, it is concluded that sustainable pumping has nothing to do with recharge. Investigating the assumptions underlying this equation, it is seen that it expresses the superposition principle, which implicitly assumes the groundwater reservoir can be depleted indefinitely and boundary conditions are an infinite source of water. To evaluate sustainability, however, the limits of the aquifer system must be examined accurately. Theoretically, this can only be accomplished applying nonlinear models, in which case setting up the simplified water budget equation is impossible without knowing the initial conditions. Hence, excluding recharge when assessing sustainable pumping may not be done inconsiderately, which is illustrated by two examples. An analytical solution, developed by Ernst in 1971 to simulate flow to a well in a polder area with a nonlinear function for drainage, even shows that it is not necessarily a misconception to assume the cone of depression stops expanding when the pumping rate is balanced by the infiltration rate.

Monitoring Land Subsidence: The Challenges of Producing Knowledge and Groundwater Management Indicators in the Bangkok Metropolitan Region, Thailand

Multiple major coastal cities face the threat of sea level rise with global climate change. This vulnerability can be further exacerbated by local contexts of urbanization and flood management. Land subsidence caused by groundwater over-extraction has long been identified as a factor that exposes cities to the threat of submergence through its interaction with the sea’s tidal regime or a river basin’s precipitation pattern and flood regime. Decision-making in regards to environmental issues such as land subsidence ultimately relies on monitoring data to frame the problem and formulate policies accordingly. Thus, in examining how subsidence has been shaped into a scientific reality in the Bangkok Metropolitan Region, this article reviews the limits and uncertainties of subsidence monitoring tools and their associated indicators for risk management (safe yield, piezometric level, and subsidence rate). Our analysis of existing technical reports, supported by interviews conducted with key actors involved in the processes of knowledge production and policy-making, has pointed out how such uncertainties give way to varied interpretations of these indicators, which continue to fuel the debate concerning the establishment of a safe yield for groundwater management. Furthermore, our research has also revealed that the monitoring of land subsidence has been receiving less priority due to institutional challenges within concerned governmental agencies. Ultimately, we argue that in order to use the resource sustainably, it is crucial to keep monitoring groundwater overdraft in the neighboring provinces of Bangkok to diligently anticipate long-term flooding risks associated with the changing hydrogeological regime of the delta.

Nitrogen management improves lodging resistance and production in maize (Zea mays L.) at a high plant density

Lodging in maize leads to yield losses worldwide. In this study, we determined the effects of traditional and optimized nitrogen management strategies on culm morphological characteristics, culm mechanical strength, lignin content, root growth, lodging percentage and production in maize at a high plant density. We compared a traditional nitrogen (N) application rate of 300 kg ha−1 (R) and an optimized N application rate of 225 kg ha−1 (O) under four N application modes: 50% of N applied at sowing and 50% at the 10th-leaf stage (N1); 100% of N applied at sowing (N2); 40% of N applied at sowing, 40% at the 10th-leaf stage and 20% at tasseling stage (N3); and 30% of N applied at sowing, 30% at the 10th-leaf stage, 20% at the tasseling stage, and 20% at the silking stage (N4). The optimized N rate (225 kg ha−1) significantly reduced internode lengths, plant height, ear height, center of gravity height and lodging percentage. The optimized N rate significantly increased internode diameters, filling degrees, culm mechanical strength, root growth and lignin content. The application of N in four split doses (N4) significantly improved culm morphological characteristics, culm mechanical strength, lignin content, and root growth, while it reduced internode lengths, plant height, ear height, center of gravity height and lodging percentage. Internode diameters, filling degrees, culm mechanical strength, lignin content, number and diameter of brace roots, root volume, root dry weight, bleeding safe and grain yield were significantly negatively correlated with plant height, ear height, center of gravity height, internode lengths and lodging percentage. In conclusion, treatment ON4 significantly reduced the lodging percentage by improving the culm morphological characteristics, culm mechanical strength, lignin content, and root growth, so it improved the production of the maize crop at a high plant density.

A spatial-temporal assessment of groundwater development in response to soil erosion

The sustainable management of water resources plays a significant role in boosting the country's economy, mainly in the agriculture sector. In many regions globally, the availability of surface water resources is limited and thus depends on the groundwater for irrigating crops. Furthermore, soil erosion is a severe problem such as worsened soil fertility, land-use disturbances, and sedimentation, especially in large-scaled river basins having complex topography. Therefore, assessment of the spatial-temporal variation of groundwater development, such as groundwater recharge (GWR) and groundwater safe yield (GWSY) and their response to topsoil erosion in large-scaled river basins, are crucial for sustainable groundwater development. This paper aims to assess the spatial-temporal dynamics of groundwater development in response to runoff–induced topsoil loss. A large-scale East African river basin such as the Omo River basin was chosen to demonstrate the proposed modeling approaches. The WetSpass-M physical-based hydrological model was used to estimate the longtime average annual GWR and runoff. The estimated spatial variation of GWR was used for the analysis of GWSY. Further, combined methods such as the RUSLE model, ArcGIS tool, and remote sensing (RS) data were used to estimate the spatial variation of annual topsoil erosion. The result showed that groundwater resources in cultivation land use in the Omo River basin have moderate to high productive aquifers (2–28 l/s), with maximum GWSY capacity ranging from 0.4 to 4 m3/day/ha. The estimated long-term average annual topsoil erosion is 12.35 t ha−1yr−1 and is comparable with the observed sediment yield of 13.24 t ha−1yr−1. The cultivation regions of the river basin receive maximum GWR and experience moderate to severe topsoil erosion, indicating that GWR has a direct response to topsoil erosion in the disturbed soil regions.

Postmortem analysis of safe-yield estimation of a heterogeneous aquifer for rural water supply

Sustainable groundwater management is founded on the sound understanding of the effects of water extraction on the aquifer water level and the springs and streams receiving groundwater discharge. Pumping test data are commonly used in extraction licence applications to evaluate aquifer properties and assess the magnitude of storage depletion resulting from pumping. However, a short duration (eg 48 hours) pumping test can fail to detect the presence of aquifer boundaries, as the cone of depression is not large enough to reach the boundaries. This may cause an underestimation of long-term drawdown and an overestimation of permissible extraction rate (ie safe yield). In the rural town of Irricana in Alberta, groundwater extraction licences for municipal water supply wells were issued in the early 1980s based on the analysis of 48-hour pumping tests. Actual water extraction rates were substantially below the licensed rates, but the unanticipated and excessive drawdown in the aquifer forced the town to discontinue pumping and switch to surface water supply after 25 years. To examine the cause of overallocation, a new 48-hour pumping test was conducted in the same aquifer, which included an extended drawdown analysis using 26 days of recovery data. Geological formation logs for existing wells in the area surrounding Irricana were used to infer the extent of sandstone aquifer units within the heterogeneous bedrock formation. The new data analysis showed that the aquifer is semi-closed, contrary to the infinite-aquifer assumption used in the original pumping test, which caused additional drawdown due to the aquifer boundary effects. This study suggests an improved procedure for estimation of storage depletion using standard hydrogeological methods and readily available data. The new procedure provides a useful tool as part of adaptive groundwater management, in which water levels and other relevant variables are monitored and licensed extraction rates are adjusted accordingly.