CONFLICTS IN WATER TRANSFER FROM IRRIGATION TO MUNICIPAL USE IN SEMIARID ENVIRONMENTS1

ABSTRACT: Conflicts caused through development of urban areas in proximity to irrigated agriculture in water-scarce regions can be minimized through the direct urbanization of irrigated lands. This shifts the water supply from one use to another on the same site rather than creating an additional use in an adjoining area. This condition has prevailed in the Phoenix region. In the Tucson region, the municipality is buying and retiring farmland in an adjacent agricultural area, for the purpose of acquiring the water right in order to transfer water to municipal use. This land purchase is necessitated by existing Arizona water law, which ties the water to the land. This method of transfer creates problems concerning how much water can be transferred per acre retired; what to do with the abandoned farmland; inequities to agribusiness and taxing entities; and loss of food crop production which have not been resolved. An alternative to the retirement of farms, applicable in the Tucson region, is to exchange treated municipal wastewater for irrigation water. While this method appears to be the least disruptive, it requires the resolution of certain institutional problems concerned with land and water management method.     

TECHNICAL AND INSTITUTIONAL ASPECTS OF SEWAGE EFFLUENT-IRRIGATION WATER EXCHANGE,TUCSON REGION1

ABSTRACT .Many growing municipalities near irrigated agriculture are advocating a transfer of water now utilized for irrigation to municipal use. Alternatives are presented whereby this water can be transferred to municipal use in exchange for treated sewage effluent. The irrigation water would in effect be cycled through the municipal system prior to use on the farms. A case study of the Tucson region illustrates the relevant legal, economic and technical aspects. Effluent could be delivered to irrigators in Avra Valley at a cost less than that now paid for water pumped from declining water tables. In return the City of Tucson could import ground water now being used for irrigation through an existing pipeline which presently cannot be used because of a court injunction obtained by the irrigators. It appears that such an exchange agreement could be made without modification of existing statutory law. Similar exchange arrangements may prove to be feasible in other regions containing irrigated agriculture. Increased efficiency of water use can be achieved avoiding external effects which commonly arise in a direct transfer and are difficult to evaluate. High quality water is allocated to municipal use whereas nutrient-rich sewage effluent is transferred to irrigation.     

DESIGN OF AN INDEX OF WATER QUALITY1

ABSTRACT: This paper describes the formulation of an Index of Water Quality to evaluate the level of pollution in fresh water. A Four-Round Delphi equation, using a panel of seven nationally recognized water scientists, was performed to ascertain the pollutants to be included in the index, the relationship between the quantity of these pollutants in the water and the resulting quality of the water, and the importance of each pollution variable to each water use as well as to overall pollution. A multiplicative index was used to bring the pollutants together into one system.     

优选法及正交试验在选择废水处理最佳条件中的应用

从试验考核指标出发，运用“水质指数（ＷＱＩ）”，分析影响废水处理效果的诸因素，选取ｐＨ值和处理剂加入量为可控因素，利用优选法找出钻井废水处理的最佳条件；选取两个因素水平进行正交试验，选用Ｌ４（２３）正交表，合理安排试验，确定最优因素水平组合。总之，应用优选法及正文试验于钻井废水处理工作中，获得了处理的最佳条件，对钻井生产中废水处理统一操作，降低消耗，保证废水处理达标率起着很重要的作用。     

AGRICULTURAL POLLUTION CONTROL: IMPLICATIONS FROM THE RURAL CLEAN WATER PROGRAM1

ABSTRACT: The Rural Clean Water Program has provided a unique opportunity to study the economics of agricultural nonpoint source pollution control. Several implications for improving the economic efficiency of future agricultural nonpoint source pollution control programs can be drawn from the results. First, individual projects should be targeted towards water bodies that have water quality problems causing economic damages. Considerable variation can exist among areas in the magnitude of economic damages, which may not be proportional to physical impacts. Second, the relative costs and effectiveness of the practices selected to reduce the delivery of pollutants can vary dramatically from one location to another. Early identification and emphasis on cost-effective BMPs can substantially reduce project costs and may make a project economically justifiable that would not otherwise be so. Finally, some projects that do not hive potential economic benefits from water quality improvements exceeding government cost may have on-farm benefits from reduced costs and increased long-term yields that are sufficient to make total benefits (water quality and on-farm) exceed costs.     

OPERATIONS RESEARCH STUDY OF WATER RESOURCES

Applications of systems methodology to water problems of the Tucson basin are summarized. Natural recharge is estimated by means of a discrete convolution relation in which the unit impulse response of an aquifer is derived from basic hydro-dynamic laws. A temporal model of sequences of wet and dry periods during the summer thunderstorm season is based on a multiple linear regression equation that relates total rainfall amount during the wet period to the duration of the wet period and volume of peak rainfall. A spatial model predicts point rainfall frequency of maximal and minimal amounts of thunderstorm rainfall. A static management model allocates Tucson groundwater, Avra Valley water, Colorado River water, and reclaimed waste water to municipal, industrial, and agricultural users within a pricing framework. For a range of pricing policies the model clearly demonstrates the opportunity costs to the community by use of higher-priced water supplies such as Colorado River water in lieu of Tucson groundwater. The role of worth of data studies in relation to data analysis, model building and management studies is also introduced.     

AN ECONOMIC ASSESSMENT OF GROUND WATER RECHARGE IN THE TUCSON BASIN1

ABSTRACT: Bringing water from Colorado River via the Central Arizona Project was perceived as the sole solution for Tucson Basin's water problem. Soon after Central Arizona Project's water arrived in Tucson in 1992, its quality provoked a quarrel over its use for potable purposes. A significant outcome of that quarrel was the enactment of the 1995 Proposition 200. The Proposition 200 precludes the use of Central Arizona Project's water for potable purposes, unless it is treated. Yet, it encourages using it for non‐potable purposes and for replenishing the Tucson aquifer through recharge. This paper examines the economic issues involved in utilizing Central Arizona Project's water for recharge. Four planning scenarios were designed to measure and compare the costs and benefits with and without Central Arizona Project's water recharge. Cost‐benefit analysis was utilized to measure recharge costs and benefits and to derive a rough estimate of cost savings from preventing land subsidence. The results indicate that the institutional requirements can be met with Central Arizona Project's water recharge. The economic benefits from reducing pumping cost and saving groundwater are not economically significant. Yet, when combining the use of Central Arizona Project's water for recharge and non‐potable purposes, it demonstrates positive net economic benefits.     

DEVELOPING COMPETITION FOR WATER IN THE URBANIZING AREAS OF COLORADO1

ABSTRACT: Rapid population growth in the metropolitan area of Denver, Colorado, is causing conflicts over water use. Two cities, Thomton and Westminster, have begun condemnation proceedings against three irrigation companies to secure agricultural water rights for municipal use. This is the first condemnation proceeding against irrigation water rights for municipal use. Should the suit succeed, over 30,000 acres of presently irrigated land will lose its water supply. There are about four hundred landowners in the area; two hundred of these are commercial farmers, including truck, dairy and specialty farms. Total agricultural production amounts to about $8 million per year. About 561 jobs related to agriculture will disappear along with about $4 million in not income. Only 6.4 percent of the farmland along the Front Range is irrigated. Continued urban growth will put pressure on the water supply of much of this land. The interested parties of the region should cooperate to lessen the impact of urban growth on agricultural lands and water by forming a metropolitan water district. Such a district could share costs of development of additional municipal water and develop systems where municipalities would recycle waste water back to the irrigated lands.     

APPLICATION OF THE CONTINUOUS STORMWATER POLLUTION SIMULATION SYSTEM (CSPSS): PHILADELLPHIA CASE STUDY1

ABSTRACT: This paper describes the Continuous Stormwater Pollution Simulation System (CSPSS) as well as a site-specific application of CSPSS to the Philadelphia urban area and its receiving water, the Delaware Estuary. Conceptually, CSPSS simulates the quantity and quality or urban stormwater runoff, combined sewer overflow, municipal and industrial waste water effuent, and upstream flow on a continuous basis for each time step in the simulation period. In addition, receiving water dissolved oxygen, suspended solids, and lead concentrations resulting from these pollutant sources may be simulated. However, only rceiving water dissolved oxygen (DO) response is considered in this paper. The continuous Do receiving water response model was calibrated to existing conditions usinv observed data at Chester, Pennsylvnia, located on the Delaware Estuary approximately 10 miles down stream from the study area. Average annual pollutant loads to the receiving water were estimated for all major sources and receiving water quality improvements resulting from removal of various portions of these pollutant loads were estimated by application of the calibrated stimultion model. It was found that the removal of oxygen-demanding pollutants from combined sewer overflow and urban stormwater runoff would result in relatively minor improvements in the overall dissoved oxygen resources of the Delaware Estuary; whereas. removal of oxygen demanding pollutants from waste water treatment plant effluent would result in greater improvemens. The results of this investigation can be used along with appropriate economic techniques to identify the most cost-effective mix of point and nonpoint source pollution control measures.     

BENEFITS FROM WATER CONSERVATION DEPEND ON COMPREHENSIVE PLANNING1

: Substantial reductions in municipal water use are feasible without reducing the quality of life. If conservation measures are preplanned, properly engineered, and coordinated, reductions in utility bills for water, waste water, and energy are estimated at $30+per person per year. Installation of devices to reduce water use, engineering plans to prevent malfunctioning of collecting sewers, and engineered process modifications of treatment facilities must be coordinated to achieve full benefits of water conservation. Pollutant discharges to the aquatic environment are reduced in direct proportion to the reduction in water use.     

COST-EFFECTIVE REGULATORY OPTIONS FOR WATER QUALITY LIMITED STREAMS1

With the pressure from industries and municipalities to reduce the waste water treatment costs associated with the permit limits needed to attain the goals of the Clean Water Act, attention has turned ways of introducing flexibility into the regulations without sacrificing the water quality goals. Wisconsin is the first state to have adopted a variety of options from which dischargers may choose when meeting their water quality requirements. These options were developed for the express purpose of minimizing the costs and maximizing the flexibility of the point source water quality regulations while ensuring that permitted discharge would not violate the water quality standards. This paper presents five options that the state has made available to dischargers, as well as one the state did not adopt. The conclusion is that a mix of options can substantially increase the flexibility and reduce the costs of meeting water quality standards on effluent limited streams.     

INDEX OF LAKE BASIN LAND USE FOR LAND USE PLANNING PURPOSES1

ABSTRACT: In order to plan for land use in a lake basin to maintain or improve lake water quality, municipal planners need a method of evaluating lakeshore and watershed land use that is technically sound, objective, reasonably quick, and cheap enough to be incorporated into their time and dollar budgets. Such a system is presented. It consists of measuring and rating four lakeshore land use characteristics (type of sewage disposal system, lot size, road proximity, and intensity of public use areas), and three upland watershed land use characteristics (intensity of development, forest cover, and agriculture and open space). These seven characteristics are measured, rated, and then combined to provide a two-digit index number. This number, when compared with the indexes of other lakes in the region and interpreted with assistance from officials of the State Health and Water Resources Department, indicates on a relative basis the degree to which various land uses are contributing to accelerated, cultural eutrophication. Interpretation of the index suggests land use controls necessary to improve lake water. It supplements, and should be used with, an index of lake vulnerability to accelerated eutrophication and a comparative measure of present water quality.     

Relative Value of Water for Hydropower and Municipal Supply in Southeastern Reservoirs

Population growth in the Southeast has driven withdrawals for municipal water beyond the limits of local supplies. With few options left for development of virgin sources, a number of urban areas are looking toward demand management and additional supplies by reallocating storage in reservoirs that were built primarily or in part for hydropower. Hydropower has become a lesser part of the mix of energy sources, and the question arises as to value of water for that purpose relative to its value for municipal use. Three cases are used to examine the issue. Effects of withdrawal for municipal water supply on output of electric energy are estimated. Benefits of foregone energy are evaluated using the least cost alternative for replacement, and benefits for municipal water are estimated using costs for development of new sources. Benefits for use as municipal water are found to be considerably higher than benefits for hydroelectric energy at existing prices, even higher than the least cost alternative for replacement. Given the spatial distribution of the cases, that finding would appear to hold in general across the region.     

Where Did the Agricultural Nonpoint Source Trades Go? Lessons from Virginia Water Quality Trading Programs

Governmental agencies, nongovernmental organizations, and agricultural organizations promote water quality trading programs as an innovative policy to engage agricultural producers in conservation activities. Cost analyses suggest regulated sources can reduce compliance costs by purchasing agricultural nonpoint source credits. Yet, such “point‐nonpoint” trades are rare. This article assesses the demand for agricultural nonpoint sources in well‐developed nutrient trading programs in Virginia for industrial and municipal wastewater treatment plants, municipal stormwater programs, and land developers. Evidence suggests nutrient trading programs in Virginia will not stimulate investments in pollutant reduction practices on working agricultural lands. The lack of demand for agricultural nonpoint source credits can be attributed to a substantial degree to the design features and incentives present in multiple overlapping regulatory programs. The legal setting that dampens regulated source demand for nonpoint source credits in Virginia is broadly representative of conditions found elsewhere in the United States.     

ENVIRONMENTAL AND ECONOMIC DAMAGE CAUSED BY SEDIMENT FROM AGRICULTURAL NONPOINT SOURCES1

Environmental and economic damages caused by agricultural nonpoint source inputs of sediment and associated pollutants are examined. Widespread water quality problems are identified in lakes, rivers, and estuaries in agricultural areas, and billions of dollars of on-site and offsite costs result from this eroded soil every year. Some water bodies have been irretrievably damaged, and expensive rehabilitation programs are needed to remedy in-place water pollution problems if Clean Water Act goals are to be achieved. Unless effective abatement and rehabilitation programs are established, billions of dollars of benefits to future generations will not be realized as more waters become irretrievably damaged, and billions more will continue to be spent by government to treat symptoms of these sediment-related problems.     

OPTIMAL ALLOCATION OF WATER QUALITY CONTROLS IN URBANIZING RIVER BASINS1

ABSTRACT: Urbanizing river basins in the west are encountering serious water quality degradation resulting from the expanded water utilization. In order to avoid aggravating such conditions, water quality controls need to be implemented. The important questions are, therefore, where and how to impose such constraints on the urban and agricultural sectors to achieve the desired level of pollution control. An application of the model developed to address such questions is made in the Utah Lake drainage area of Central Utah as a test of the model's utility. The region is subdivided into five major sub-basins containing both municipal and agricultural water demands. A submodel of each sub-basin is developed which optimizes the water quality control strategies by linking the urban to the agricultural uses and then evaluating the levels of control for each sector. From these results, a cost-effectiveness function for each sub-basin is generated. By jointly considering the cost-effectiveness relationship for each sub-basin, an optimum policy for the entire basin is determined.     

SYSTEMS FOR RAINFALL AND RUNOFF USE,TUCSON, ARIZONA1

Rainfall and runoff in the Tucson, Arizona, urban area can be used to augment residential and municipal water supplies. Residential rainfall-harvesting systems include a catchment surface, collection and concentration components, separation and treatment units, storage capacity and distribution capability. A system to control runoff can divert water from urban washes for use in parks or other landscaped areas or can be used to enhance recharge to groundwater reservoirs. A reduction in flood hazards or peaks is a concurrent benefit of controlling and diverting runoff.     

DECISION SUPPORT FOR ALLOCATION OF WATERSHED POLLUTION LOAD USING GREY FUZZY MULTIOBJECTIVE PROGRAMMING1

ABSTRACT: This paper uses the grey fuzzy multiobjective programming to aid in decision making for the allocation of waste load in a river system under versatile uncertainties and risks. It differs from previous studies by considering a multicriteria objective function with combined grey and fuzzy messages under a cost benefit analysis framework. Such analysis technically integrates the prior information of water quality models, water quality standards, wastewater treatment costs, and potential benefits gained via in‐stream water quality improvement. While fuzzy sets are characterized based on semantic and cognitive vagueness in decision making, grey numbers can delineate measurement errors in data collection. By employing three distinct set theoretic fuzzy operators, the synergy of grey and fuzzy implications may smoothly characterize the prescribed management complexity. With the aid of genetic algorithm in the solution procedure, the modeling outputs contribute to the development of an effective waste load allocation and reduction scheme for tributaries in this subwatershed located in the lower Tseng‐Wen River Basin, South Taiwan. Research findings indicate that the inclusion of three fuzzy set theoretic operators in decision analysis may delineate different tradeoffs in decision making due to varying changes, transformations, and movements of waste load in association with land use pattern within the watershed.     

从水污染防治角度出发的全国分省域水环境安全研究

针对我国日益严峻的水环境安全问题,本文从水污染防治角度出发,依据影响我国水环境安全的关键污染问题,即水环境质量、水污染物排放、水环境风险,构建了水环境安全指标体系。利用相关分析法、主成分分析法,简化、优化评价指标体系。利用层次分析法与专家打分法,估算各指标权重,采集各指标数据对全国31个省(自治区、直辖市)2011—2013年的水环境安全状况进行评估。结果表明:该指标体系在一定条件和范围内是合理的,我国水环境安全大体呈西高中东低的空间分布,京津冀区域水环境安全评价值较低。"十三五"时期,京津冀地区应着重于降低主要污染物浓度,削减劣V类断面比例,提高水环境质量,海南、福建、广东等地区着力于减少农业等水污染物排放强度,湖南等地区则需要重点关注涉重企业的污染物排放。     

A Framework for Incorporating the Impact of Water Quality on Water Supply Stress: An Example from Louisiana,USA

Water of poor quality can directly impact the budget of water available for key user groups. Despite this importance, methods for quantifying the impact of water quality on water availability remain elusive. Here, we develop a new framework for incorporating the impact of water quality on water supply by modifying the Water Supply Stress Index (WaSSI). We demonstrate the usefulness of the framework by investigating the impact of high salinity waters on the availability of irrigation water for agriculture in Louisiana. The WaSSI was deconstructed into sectoral components such that the total available water supply could be reduced for a particular demand sector (agricultural irrigation in this example) based on available water quality information. The results for Louisiana highlight substantial impacts on water supply stress for farmers attributable to the landward encroachment of saline surface water and groundwater near the coast. Areas of high salinity near the coast also increased the competition for freshwater resources among the industrial, municipal, and agricultural demand sectors in the vicinities of the municipal areas of Lake Charles, Lafayette, and Baton Rouge, Louisiana. The framework developed here is easily adaptable for other water quality concerns and for other demand sectors, and as such can serve as a useful tool for water managers.