WATER SUPPLY IMPACTS OF NUCLEAR FALL1

ABSTRACT: “Nuclear winter,” more properly called “nuclear fall,” could be caused by injection of large amounts of dust into the atmosphere. Besides causing a decrease in temperature, it could be accompanied by “nuclear drought,” a catastrophic decrease in precipitation. Dry land agriculture would then be impossible, and municipal, industrial, and irrigation water supplies would be diminished. It has been argued that nuclear winter/fall poses a much greater threat to human survival than do fall out or the direct impacts of a conflict. However, this does not appear to be true, at least for the U.S. Even under the unprecedented drought that could result from nuclear fall, water supplies would be available for many essential activities. For the most part, ground water supplies would be relatively invulnerable to nuclear drought, and adequate surface supplies would be available for potable uses. This assumes that conveyance facilities and power supplies survive a conflict largely intact or can be repaired.     

Household use of and satisfaction with alternative water sources in Victoria Australia

Climate change is increasing the variability of rainfall, and thus the availability of water supplies in many areas of the world. These impacts are already being felt in the state of Victoria, Australia where a 12 year drought period was recently experienced. Restrictions to water use have been implemented, as one component of a broad policy approach to manage the drought. While anecdotal evidence suggests that the substitution of centralised water supplies is occurring, this has not been proven empirically. This paper reports results from a survey of households in Victoria regarding their use of alternative water sources. The study found that substitution is occurring. Garden watering is the purpose which has the highest rate of alternative water source use. In total 41.6% of respondents always, and 33.2% sometimes use an alternative water source for garden watering. The most commonly used alternative source of water for garden watering is water previously used in the laundry (30.7%). The alternative source of water used was found to vary depending on the purpose of the water use. High levels of satisfaction were found for all alternative water sources used. Several barriers were found to the use of alternative water sources, the main of which were: inflexibility of existing infrastructure, cost, policy, and housing status. The results have implications for water retailers, policy makers and governments in locations facing water shortage.     

EVALUATION OF GREAT LAKES NET BASIN SUPPLY FORECASTS1

ABSTRACT: Evaluation of the Great Lakes Environmental Research Laboratory's (GLERL's) physically-based monthly net basin supply forecast method reveals component errors and the effects of model improvements for use on the Laurentian Great Lakes. While designed for probabilistic outlooks, it is assessed for giving deterministic outlooks along with other net basin supply forecast methods of the U.S. Army Corps of Engineers and Environment Canada, and with a stochastic approach commissioned by the Corps. The methods are compared to a simple clima-tological forecast and to actual time series of net basin supplies. Aetual net basin supplies are currently determined by estimating all components directly, instead of as water-balance residuals. This is judged more accurate and appropriate for both forecasting and simulation. GLERL's physically-based method forecasts component supplies while the other methods are based on residual supplies. These other methods should be rederived to be based on component supplies. For each of these other methods, differences between their outlooks and residual supplies are used as error estimates for the rederived methods and component supplies. The evaluations are made over a recent period of record high levels followed by a record drought. Net basin supply outlooks are better than climatology, and GLERL's physically-based method performs best with regard to either component or residual net basin supplies. Until advances are made in long-range climate outlooks, deterministic supply outlooks cannot be improved significantly.     

Available Water Supplies in Beijing,China, Under Single‐ and Multi‐Year Drought

Since its implementation in 2015, the Middle Route of the South‐to‐North Water Diversion Project (MR‐SNWDP) has transferred an average of 45 billion cubic meters of surface water per year from the Yangtze River in southern China to the Yellow River and Hai River Basin in northern China, but how that supply is able to cope with droughts under different scenarios has not been explored. In this study, using the water demand for 2020 as the guaranteed water target, a Water Evaluation and Planning system was used to simulate available water supplies in Beijing under different drought scenarios. In the case of a single‐year drought, without the MR‐SNWDP, Beijing’s water shortage ratio was 16.7%; with the MR‐SNWDP, this ratio reduced to 7.3%. In the case of a multi‐year drought, without the MR‐SNWDP, Beijing’s water shortage ratio was 25.3%; with the MR‐SNWDP, this ratio reduced to 7.4% and domestic water supply was improved. Our research suggests that to prepare for multi‐year drought in the Beijing area, the SNWDP supports increased supplies to the region that would mitigate drought effects. This study is, however, mostly focused on water supply provision to Beijing and does not comprehensively evaluate other potential impacts. Multiple additional avenues could be pursued that include replenishing groundwater, increasing reservoir storage, and water conservation methods. Further research is needed to explore the relative costs and benefits of these approaches.     

INSTITUTIONAL OPTIONS FOR THE COLORADO RIVER1

ABSTRACT: In many interstate river basins, the institutional arrangements for the governance and management of the shared water resource are not adequately designed to effectively address the many political, legal, social, and economic issues that arise when the demands on the resource exceed the available supplies. Even under normal hydrologic conditions, this problem is frequently seen in the Colorado River Basin. During severe sustained drought, it is likely that the deficiencies of the existing arrangements would present a formidable barrier to an effective drought response, interfering with efforts to quickly and efficiently conserve and reallocate available supplies to support a variety of critical needs. In the United States, several types of regional arrangements are seen for the administration of interstate water resources. These arrangements include compact commissions, interstate councils, basin interagency committees, interagency-interstate commissions, federal-interstate compact commissions, federal regional agencies, and the single federal administrator. Of these options, the federal-interstate compact commission is the most appropriate arrangement for correcting the current deficiencies of the Colorado River institution, under all hydrologic conditions.     

GROUND WATER QUALITY PREDICTION USING CLIMATIC INDICES1

ABSTRACT: Drought affects the quality of ground water in certain aquifers used by municipalities in Kansas. Water quality changes occur as a function of the amount of water available for recharge and hence to dilute more mineralized ground waters. Several measures of meteorological drought, including the Palmer Index and Eagleman Aridity Index, were correlated with water quality data to determine the degree of association. Several locations showed sharp delinces in water quality as the drought progressed. These relationships can be used to predict possible variations in present and future well-water supplies in locations subject to drought induced water quality deterioration.     

FLEXIBLE PRICING IN WATER SUPPLY PLANNING–FOR FLEXIBLE ENGINEERS1

ABSTRACT. Preliminary results from a digital simulation model designed to test time-varying water pricing policies are presented. Stochastic inflows feeding a water supply reservoir are assumed for a hypothetical community with defined demand functions. Prices are allowed to vary as a function of reservoir level, generally rising as reservoir levels fall. Increasing, decreasing and constant rates are tested. It is concluded that varying the price to reflect the increased value of scarce supplies can greatly reduce the risk of water supply shortages. It is also concluded that varying incremental (conservational) pricing policies not only reduces the risk of shortages, but also lowers the average price to the community while rewarding the low consumption user with lower average rates.     

Meadow Restoration Increases Baseflow and Groundwater Storage in the Sierra Nevada Mountains of California

In mountains of the western United States, channel incision has drawn down the water table across thousands of square kilometers of meadow floodplain. Here climate change is resulting in earlier melt and reduced snowpack and water resource managers are responding by investing in meadow restoration to increase springtime storage and summer flows. The record‐setting California drought (2012–2015) provided an opportunity to evaluate this strategy under the warmer and drier conditions expected to impact mountain water supplies. In 2012, 0.1 km² of meadow floodplain was reconnected by filling an incised channel through Indian Valley in the central Sierra Nevada Mountains of California. Despite sustained drought conditions after restoration, summer baseflow from the meadow increased 5–12 times. Before restoration, the total summer outflow from the meadow was 5% more than the total summer inflow. After restoration, total summer outflow from the meadow was between 35% and 95% more than total summer inflow. In the worst year of the drought (2015), when inflow to the meadow ceased for at least one month, summer baseflow was at least five times greater than before restoration. Groundwater levels also rose at four out of five sites near the stream channel. Filling the incised channel and reconnecting the meadow floodplain increased water availability and streamflow, despite unprecedented drought conditions.     

MUNICIPAL WATER USE AND WATER RATES DRIVEN BY SEVERE DROUGHT: A CASE STUDY1

ABSTRACT: This paper synthesizes and interprets data pertaining to the evolution of average water revenue, water use, and the average cost of water supply in the City of Santa Barbara, California, from 1986 to 1996, a period which included one of the most devastating droughts in California this century. The 1987–1992 drought hit the study area particularly hard. The City of Santa Barbara was dependent exclusively on local sources for its water supply. That made it vulnerable as the regional climate is prone to extreme variability and recurrent droughts. The 1986–1992 drought provided a rare opportunity to assess the sensitivity of municipal water use to pricing, conservation, and other water management measures under extreme drought conditions. Our analysis indicates that the average cost of water rose more than three-fold in real terms from 1986 to 1996, while the gap between the average cost of supply and the average revenue per unit of water (= 100 cubic feet) rose in real terms from $0.14 in 1986 to $ 0.75 in 1996. The rise of $3.08 in the average cost of supplying one unit of water between 1986 and 1996 measures the cost of hedging drought risk in the study area. Water use dropped 46 percent at the height of the drought relative to pro-drought water use, and remains at 61 percent of the pre-drought level. The data derived from the 1987–1992 California drought are unique and valuable insofar as shedding light on drought/water demand adaptive interactions. The experience garnered on drought management during that unique period points to the possibilities available for future water management in the Arid West where dwindling water supplies and burgeoning populations are facts that we must deal with.     

ASSESSMENT ANALYSIS FOR WATER SUPPLY ALTERNATIVES1

ABSTRACT Providing adequate water supplies of good quality is becoming a serious problem in many areas of the United States. Some of the alternatives proposed for meeting the growing shortage of clean-water or cheap-water are reallocation, reuse, and importation. This paper outlines a methodology to assess all of these water supply alternatives by examining the amount and time-staging for development of water sources. In conceptualizing the problem, sources of supply are classified in three categories: primary or base supplies, secondary or effluent supplies, and supplementary or imported supplies. A model of the water system is formulated as a “transportation problem” in linear programming depicting the possible sources of supply which can be used to satisfy the requirements of various water users. The optimizing objective in the model is to minimize the cost of water under various assumptions for operating the system. A case study of the Salt Lake Qty, Utah, area is used to illustrate the application of the model in obtaining optimal water supply allocations for projected future demands. Assessment of alternatives in the study include redistribution of supplies, time-staging of supplies and related treatment facilities, and sensitivity of allocations to changes in costs.     

MEASURING DROUGHT IMPACTS: THE ILLINOIS CASE1

ABSTRACT: Drought is an interaction between physical processes and human activities. This study quantified the impacts of precipitation deficiencies on streamflow, reservoirs, and shallow ground water supplies. An in-depth analysis of newspaper accounts of droughts between paired cities, one in drought and one not in drought, were used to measure the differences in the types of drought impacts, and in the time of onset of impacts as related to developing precipitation deficiencies. Precipitation deficiencies related to the onset and the magnitude of surface water supply adjustments, and to shallow ground water problems, were established. Thus, monitoring and prediction of the onset and magnitude of drought problems can now be done from readily available data on precipitation deficiencies. Newspapers were found to be reliable indicators for the timing of drought impacts and adjustments as precipitation deficiency develops. A review of local and state adjustments during two recent droughts revealed most decision makers lacked information and experience in dealing with drought.     

SPATIAL VARIATIONS OF WATER LOSS DURING DROUGH A CASE STUDY1

ABSTRACT: A regional water conservation system for drought management involves many uncertain factors. Water received from precipitation may stay on the ground surface, evaporate back into the atmosphere, or infiltrate into the ground. Reliable estimates of the amount of evapotranspiration and infiltration are not available for a large basin, especially during periods of drought. By applying a geographic information system, this study develops procedures to investigate spatial variations of unavailable water for given levels of drought severity. Levels of drought severity are defined by truncated values of monthly precipitation and daily streamflow to reflect levels of water availability. The greater the truncation level, the lower the precipitation or streamflow. Truncation levels of monthly precipitation are recorded in depth of water while those of daily streamflow are converted into monthly equivalent water depths. Truncation levels of precipitation and streamflow treated as regionalized variables are spatially interpolated by the unbiased minimum variance estimation. The interpolated results are vector values of precipitation and streamflow at a grid of points covering the studied basin. They are then converted into raster‐based values and expressed graphically. The image subtraction operation is used to subtract the image of streamflow from that of precipitation at their corresponding level of drought severity. It is done on a cell‐by‐cell basis resulting in new attribute values to form the spatial image representing a spatial distribution of potential water loss at a given level of drought severity.     

Drought planning and water allocation: an assessment of local capacity in Minnesota

Water allocation systems are challenged by hydrologic droughts, which reduce available water supplies and can adversely affect human and environmental systems. To address this problem, drought management mechanisms have been instituted in jurisdictions around the world. Historically, these mechanisms have involved a crisis management or reactive approach. An important trend during the past decade in places such as the United States has been a shift to a more proactive approach, emphasizing drought preparedness and local involvement. Unfortunately, local capacity for drought planning is highly variable, with some local governments and organizations proving to be more capable than others of taking on new responsibilities. This paper reports on a study of drought planning and water allocation in the State of Minnesota. Factors facilitating and constraining local capacity for drought planning were identified using in-depth key informant interviews with state officials and members of two small Minnesota cities, combined with an analysis of pertinent documentation. A key factor contributing to the effectiveness of Minnesota's system is a water allocation system with explicit priorities during shortages, and provisions for restrictions. At the same time, the requirement that water suppliers create Public Water Supply Emergency Conservation Plans (PWSECP) clarifies the roles and responsibilities of key local actors. Unfortunately, the research revealed that mandated PWSECP are not always implemented, and that awareness of drought and drought planning measures in general may be poor at the local level. From the perspective of the two cities evaluated, factors that contributed to local capacity included sound financial and human resources, and (in some cases) effective vertical and horizontal linkages. This analysis of experiences in Minnesota highlights problems that can occur when senior governments establish policy frameworks that increase responsibilities at the local level without also addressing local capacity.     

IMPACT OF DROUGHT ON QUALITY IN A NEW JERSEY WATER SUPPLY SYSTEM1

ABSTRACT. New Jersey, together with other states in the northeast, was stricken with drought during 1961-66. The effect of this drought was most severe in the northern part of the State. The water quality of the Passaic River, which drains the urban, industrialized northeast, perhaps deteriorated the most among the major drainage systems. This river system is used as a raw-water source by 10 water suppliers. The impact of the drought upon the water supply of the Passaic Valley Water Commission, the most downstream of the basin's suppliers, which supplies an average of about 90 million gallons a day to more than 650,000 persons, is evaluated herein. The drought's impact on the raw-water quality is appraised by the comparison of before-and-after qualities of dissolved solids, dissolved oxygen, biochemical-oxygen demand, turbidity, and hardness. For example, at the worst point during the drought, monthly average dissolved-solids content in the raw water were about 210 percent, hardness, about 167 percent, and biochemical-oxygen demand about 270 percent higher than antecedent values. In general, the study concludes that the drought produced a deterioration in both raw and finished water quality, and is estimated to have increased chemical-treatment costs during the drought by about $650,000.     

USE OF A DAM BREAK MODEL TO ASSESS FLOODING AT HADDAM NECK NUCLEAR POWER PLANT1

Because of their proximity to necessary supplies of cooling water, nuclear power plants are susceptible to riverine flooding. Greater flood hazards exist where plants are located downstream of large dams. The consequences of the Quabbin Reservoir dam failure on the Haddam Neck Nuclear Power Plant situated on the Connecticut River were investigated using a dam break flood routing model. Reasons for selecting a particular model are presented and the input assumptions for the modeling process are developed. Relevant information concerning the level of manpower involvement is presented. The findings of this analysis demonstrate that the plant is adequately protected from the consequences of the postulated flood event.     

A Long View of Southern California Water Supply: Perfect Droughts Revisited

The impact of drought on water resources in arid and semiarid regions can be buffered by water supplies from different source regions. Simultaneous drought in all major source regions — or perfect drought — poses the most serious challenge to water management. We examine perfect droughts relevant to Southern California (SoCal) water resources with instrumental records and tree‐ring reconstructions for the Sacramento and Colorado Rivers, and SoCal. Perfect droughts have occurred five times since 1906, lasting two to three years, except for the most recent event, 2012–2015. This number and duration of perfect droughts is not unusual in the context of the past six centuries. The modern period stands out for the relatively even distribution of perfect droughts and lacks the clusters of perfect drought documented in prior centuries. In comparison, perfect droughts of the 12th Century were both longer (up to nine years) and more widespread. Perfect droughts of the 20th and 21st Centuries have occurred under different oceanic/atmospheric patterns, zonal and meridional flow, and ENSO or non‐ENSO conditions. Multidecadal coherence across the three regions exists, but it has varied over the past six centuries, resulting in irregular intervals of perfect drought. Although the causes of perfect droughts are not clear, given the long‐term natural variability along with projected changes in climate, it is reasonable to expect more frequent and longer perfect droughts in the future.     

Characterizing Drought in Irrigated Agricultural Systems: The Surface Water Delivery Index (SWDI)

Quantifying surface water shortages in arid and semiarid agricultural regions is challenging because limited water supplies are distributed over long distances based on complex water management systems constrained by legal, economic, and social frameworks that evolve with time. In such regions, the water supply is often derived in a climate dramatically different from where the water is diverted to meet agricultural demand. The existing drought indices which rely on local climate do not portray the complexities of the economic and legal constraints on water delivery. Nor do these indices quantify the shortages that occur in drought. Therefore, this research proposes a methodological approach to define surface water shortages in irrigated agricultural systems using a newly developed index termed the Surface Water Delivery Index (SWDI). The SWDI can be used to uniformly quantify surface water deficits/shortages at the end of the irrigation season. Results from the SWDI clearly illustrate how water shortages in droughts identified by the existing indices (e.g., SPI and PDSI) vary strongly both within and between basins. Some surface water entities are much more prone to water shortages than other entities based both on their source of water supply and water right portfolios.     

An integrated assessment of long-term changes in the hydrology of three lowland rivers in eastern England

The flow records of the Rivers Bure, Nar and Wensum in eastern England have been examined with the aim of identifying long-term changes in flow behaviour relating to variations in rainfall amount, land use, land drainage intensity and water resources use. In the study area, and since 1931, there is no evidence of long-term change in rainfall amount or distribution, on either an annual or seasonal basis. Despite changes in water resources use and catchment characteristics since the beginning of the century, such as the ending of water milling and increased land drainage and arable farming, rainfall-runoff modelling over the period 1964-1992 showed that the relationship between rainfall and runoff has remained essentially unchanged in the three study rivers. A catchment resource model used to 'naturalise' the historic flow records for the period 1971-1992 to account for the net effect of water supply abstractions and discharges revealed that mean river flows have been altered by surface water and groundwater abstractions, although the average losses to mean weekly flows due to net abstractions for all water uses was no greater than 3%. Greater losses occurred during drought periods as a result of increased consumptive use of water for spray irrigation and amounted to a maximum loss of 24% in the Nar catchment. In lowland areas such as eastern England that are prone to summer dry weather and periodic drought conditions, an integrated approach to river basin management, as advocated by the EU Framework Directive, is recommended for future management of surface and groundwater resources for public water supplies, river regulation purposes and industrial and agricultural demands.     

GROUND WATER DROUGHT MANAGEMENT BY A FEEDFORWARD CONTROL METHOD1

ABSTRACT: Management of a regional ground water system to mitigate drought problems at the multi‐layered aquifer system in Collier County, Florida, is the main topic. This paper developed a feedforward control system that consists of system and control equations. The system equation, which forecasts ground water levels using the current measurements, was built based on the Kalman filter algorithm associated with a stochastic time series model. The role of the control equation is to estimate the pumping reduction rate during an anticipated drought. The control equation was built based on the empirical relationship between the change in ground water levels and the corresponding pumping requirement. The control system starts with forecasting one‐month‐ahead ground water head at each control point. The forecasted head is in turn used to calculate the deviation of ground water heads from the monthly target specified by a 2‐in‐10‐year frequency. When the forecasted water level is lower than the target, the control system computes spatially‐varied pumping reduction rates as a recommendation for ground water users. The proposed control system was tested using hypothetical droughts. The simulation result revealed that the estimated pumping reduction rates are highly variable in space, strongly supporting the idea of spatial forecasting and controlling of ground water levels as opposed to a lumped water use restriction method used previously in the model area.     

NETWORK MODEL FOR DECISIONSUPPORT IN MUNICIPAL RAW WATER SUPPLY1

ABSTRACT: A water supply network optimization model called MODSIM3 is presented as a decision-support tool for aiding city staff in determining how best to utilize and exchange existing and potential water supplies with other users in a river basin. The model is applied to the City of Fort Collins, Colorado, water supply system as a means of determining optimum ways the City can utilize direct flow rights, storage rights, and exchangeable waters from various sources. Results clearly confirm both the benefits of the use of exchanges and the value of MODSIM3 as a water supply planning and management tool.