OPTICAL IMPACTS AND SOURCES OF SUSPENDED SOLIDS IN ONONDAGA CREEK,U.S.A.1

ABSTRACT: The degradation of the optical aesthetics in the mouth of Onondaga Creek, New York, that occurs during high flow periods as a result of the influx of large quantities of suspended solids, is documented. Features of the degradation include very low clarity (Secchi disc minimum of approximately 0.1 m) and a brown ‘muddy’ appearance. The reduced clarity is mostly a result of increased light scattering. Loading and concentration profiles obtained for an approximately 35 km interval above the creek mouth over a wide range of flow indicates most of the suspended solids received during runoff events is resuspended stream sediment and eroded bank material. Application of microscopy-based individual particle analysis techniques indicates that the origin of most of these deposits and much of the suspended solids during runoff events is point source inputs, termed ‘mud boils,’ located approximately 32 km upstream of the creek mouth.     

MACROPHYTE COMMUNITY DYNAMICS IN A DREDGED WISCONSIN LAKE1

ABSTRACT This paper describes the change in the macrophyte community caused by dredging a small Wisconsin lake. In water depths up to 1.5 m, revegetation was rapid after dredging. The plant community changed from one dominated by large-leafed Potamogeton (pondweed), Megalodonta beckii (water marigold), and Elodea canadensis (waterweed) to one dominated by Chara (stonewort), Najas flexilis (naiad), and Myriophyllum (milfoil). Plant growth ended at the 4 m depth and growth recovered much more slowly in water depths between 1.5 and 4 m. The area between 1.5 m and 2.5 m in particular supported a monotypic milfoil stand after dredging.     

CHLOROPHYLL,PHOSPHORUS, SECCHI DISK,AND TROPHIC STATE1

ABSTRACT: The relationship between chlorophyll u, total phosphorus, secchi disk depth, and trophic state were examined using data on U.S. lakes collected by U.S. EPA's National Eutrophication Survey. By comparing predicted secchi disk depths with observed summer secchi disk depths in 757 lakes, it was determined that in many lakes non-chlorophyll related light attenuation is important in controlling the amount of chlorophyll u produced per unit of total phosphorus. Ranking of 44 lakes by 18 different trophic state measurements and single and multivariable indices were compared with rankings provided by mean summer ambient total phosphorus and chlorophyll u. The trophic state measurements and indices were much more successful in ranking the lakes against total phosphorus than chlorophyll u, indicating that there are differences in the relative trophic rankings of many of the lakes depending upon whether primary nutrients or biological manifestations are used as the ranking mechanism. If the manifestations of nutrients rather than their absolute levels are the primary criteria for beneficial use of lakes, the use of many of the commonly employed trophic state measurements, which assume or imply that there is a constant relationship between total phosphorus or secchi disk and chlorophyll, can lead to erroneous conclusions and unnecessary costly management controls. Secchi disk measurements may be more useful as a predictor of ambient lake total phosphorus concentrations than of chlorophyll.     

WATER QUALITY ALLOCATED COST FOR MULTIPURPOSE RESERVOIRS1

ABSTRACT: Low flow augmentation from multipurpose reservoirs may yield significant water quality benefits. Cost allocation assigns a portion of reservoir expense to water quality consumers, waste water dischargers who benefit from increased receiving flow. Whereas such allocation currently is not authorized for Federal projects, the procedure is increasingly appropriate for efficient multiobjective management. Waste water treatment costs, multipurpose reservoir costs, and water quality are modeled for Oregon's Willamette River. Water quality is expressed as a function of treatment and augmentation levels. Treatment cost necessary to achieve a given water quality without augmentation less treatment cost with augmentation is an alternative cost of water quality maintenance. With a cost allocation procedure, this alternative cost is used to determine water quality's share of reservoir cost. Under current conditions, water quality beneficiaries could be charged approximately seven percent of annualized reservoir expense. This charge is one-fourth the expense of additional treatment facilities required were augmentation not provided.     

RESERVOIR YIELD: AN IMPORTANT ENVIRONMENTAL PARAMETER1

ABSTRACT: Analysis of the storage-yield relationship can be used to help resolve conflicts between environmental values and water resources development. New Melones Reservoir in northern California presents a classic example of such a conflict between preservation of white water for recreational purposes and development of the site for a major multi-purpose reservoir. Analysis of the storage yield relationship for the proposed New Melones project indicates potential trade-offs between white water preservation and reservoir yield.     

A RISK-BASED MODEL FOR DROUGHT CONTINGENCY PLANNING1

ABSTRACT: A risk-based model is presented for determining action levels in real-time operation of public water supplies under drought conditions. The model, applicable to surface water supplies, is built around the almost universally adopted structure for drought management, a sequence of increasingly stringent measures to reduce demand. Action levels are determined by finding minimum storage levels that will satisfy a prescribed set of probability constraints over the remainder of a drawdown-refill cycle. Results are presented for the City of Raleigh, NC.     

PRELIMINARY HYDROLOGIC DESIGN OF SMALL FLOOD DETENTION RESERVOIRS1

ABSTRACT. Flood detention reservoir design is a common problem encountered by engineers and others involved with water resources problems. This paper presents a method by which the volume of flood storage required for a single reservoir or a series of reservoirs may be estimated without using numeric flood-routing techniques. The proposed procedure requires a minimum of computations and is most applicable to preliminary design situations where a high degree of accuracy is not required.     

SOCIAL CLASS DIFFERENCES IN RESERVOIR VISITS1

ABSTRACT: Previous research provides evidence of a socioeconomic bias in outdoor recreational participation. One explanation of this bias is that socioeconomic groups have differential opportunities to participate, with the “costs” of this participation especially serving to restrict the recreational access of lower class persons living in urban areas. Using driving distance as a measure of cost, this study assessed the effects of travel costs on the attendance of three social class groups from an urban population at rural reservoir facilities. Findings support the contention that, while increased driving distance has a dampening effect on recreational participation, this effect is most pronounced for the lower class person. These findings point to the importance of equity considerations in the planning of outdoor recreational facilities.     

FEASIBILITY OF INTERBASIN WATER TRANSFER1

ABSTRACT: Interbasin water transfer is one of the most controversial water-resources-planning topics. Local communities, particularly those from which the water is to be taken (donor regions), generate enough opposition to doom many projects to failure. The opposition often arises because planners have traditionally considered excess water a free commodity rather than a marketable resource. To make transfer schemes mutually acceptable to donor and recipient regions, visible benefits must be offered. Agreement must be made on an acceptable purchase price and/or on other benefits such as a substantial amount of low flow augmentation or possibly some degree of flood control on the donor source stream. The hydrologic and economic feasibility of water transfer from the East Susquehanna River basin to the Delaware Reservoir System for supplemental supply to the New York City area was investigated. Nine alternative schemes for diversions up to 400 cfs and compensations in the form of low flow augmentation and/or flood control were considered resulting in unit costs to the recipient region between $90 and $380/mg. If only the minimum state-mandated flow is released to the Susquehanna River, the savings to the water recipients would be sufficient to pay a purchase price of about $21/mg, which would be equivalent to a total amount of $420,000/year for an average export of 100 cfs.     

MANGANESE OXIDATION RELATED TO THE RELEASES FROM RESERVOIRS1

ABSTRACT: Stratified reservoir waters frequently contain objectionable quantities of dissolved manganese. The oxidation and removal of dissolved manganese during transport below Normandy Dam, Tennessee, was shown to be much more rapid than expected from chemical oxidation. Oxidation took place in only a day of travel time rather than months or years. Laboratory studies showed that removal was associated with a slime found on rock surfaces below the dam and led to the development of column technology as a possible method of treating natural waters containing manganese. Hydraulic loadings on the columns in the range of 390–780 m³/hr.ha accomplished a 90 percent removal rate of soluble manganese over an influent concentration range of 2 to 15 mg/l.     

PRELIMINARY DESIGN AND COST ESTIMATING FOR RESERVOIR PROJECTS1

ABSTRACT: In estimating the costs of a reservoir project, it is difficult to produce accurate costs without performing a detailed design and quantity takeoff. The computerized procedure presented in this article provides a method for determining these planning level costs quickly and easily, while maintaining reasonable accuracy.     

GEOMETRIC VARIATIONS IN RESERVOIR WATER QUALITY1

ABSTRACT: In developing water quality models for lakes and reservoirs, the assumptions of one-dimensionality (i.e., water quality changes are significant only in one dimension – usually depth), as well as two-dimensionality (considering the length and depth of the water body), have been utilized to predict water quality. In both caws, the assumption of lateral homogeneity is made. A field study was undertaken to determine the change of water quality in the lateral dimension. The main study reservoir was Center Hill Lake in Middle Tennessee. Data were also obtained for Cherokee Lake in East Tennessee. Several water quality parameters (temperature, dissolved oxygen, pH, conductivity, and oxidation reduction potential) were analyzed over the length, breadth, and depth of these reservoirs from pre-stratification through post-stratification. The statistical and theoretical three-dimensional analysis showed the expected variation for each water quality parameter in each direction. The influence of the lateral dimension on water quality management and modeling was found to be negligible.     

RECREATION AT DRINKING WATER RESERVOIRS IN MASSACHUSETTS: A SURVEY OF WATER MANAGERS1

The purpose of this study was to identify attitudes toward the recreational use of drinking water reservoirs in Massachusetts among municipal water supply managers in the state. Compared to the findings of recent studies assessing the attitudes of the general public, water officials were found to advocate highly restrictive views. No officials said that recreation was an insignificant source of water supply pollution; however, opinions were not found to be related to respondents' exposure to the literature on the topic. The majority were not, in fact, familiar with the literature assessing the impact of recreation on water supply reservoirs.     

DISSOLVED OXYGEN MODEL OF A SHORT DETENTION TIME RESERVOIR WITH ANAEROBIC HYPOLIMNION1

ABSTRACT: A vertical dissolved oxygen model was calibrated and verified using independent field data sets from 1972 and 1973 in Lake Lyndon B. Johnson (LBJ), a short detention time reservoir with anaerobic hypolimnion. Ammonia, carbonaceous BOD, conductivity, and temperature were also simulated as state variables. The conductivity results provided a check on the mass balance and the method of entering the inflows to the reservoir model. Emphasis was placed on calculating the sinks of dissolved oxygen in the hypolimnion which could be useful in management decisions.     

THE AMERICAN INDIAN AND MISSOURI RIVER WATER DEVELOPMENTS1

ABSTRACT: The construction of three Missouri River main stem dams, Garrison, Oahe and Fort Randall, and the related reservoir taking caused social and economic changes on five Indian reservations, Fort Berthold, Cheyenne River, Standing Rock, Crow Creek and Lower Brute. The inundation of Missouri River riparian lands caused the loss of important cultural, social and economic environments. Ninety percent of the reservations timber, seventy-five percent of its wildlife and most of the fertile cropland were in the reservoir taking area. Urban and more fertile environments downstream and to the east received most of the projects benefits. The Indian minority on the five reservations received few economic and social benefits after bearing a disporportionate share of the social and economic costs of the developments. Relocation was forced upon those who had the longest historic and cultural claim to the land. The social costs to the American Indian occasioned by the Missouri River water developments illustrates two broad areas seldom considered during the decision process. First, the unique historic, cultural or religious values of minorities affected by developments. Second, the disproportionate spacial allocation of both benefits and costs. The second item includes social, economic and cultural considerations in not just a geographic framework but a cultural framework as well.     

AN ALGORITHM FOR ESTIMATING SURFACE SUSPENDED SEDIMENT CONCENTRATIONS WITH LANDSAT MSS DIGITAL DATA1

ABSTRACT: Algorithms for Landsat MSS digital data are needed to reduce the necessity of calibrating each Landsat scene if these data are to be useful in monitoring programs for surface suspended sediments. In this study digital data were extracted from 16 Landsat Multispectral Scanner (MSS) scenes collected between March 1987 and August 1988 over Enid Reservoir in North Central Mississippi. These data were converted to radiance and reflectance data for comparison with field measurements of surface suspended sediment concentrations. Concentrations ranged from 2 to 168 mg/1 during the study with only four greater than 100 mg/l. Linear and polynomial regression analyses were used to relate the surface suspended sediment concentrations with radiance and reflectance. Reflectance in MSS band 2 (0.6 to 0.7 μm) and MSS band 3 (0.7 to 0.8 μm) were best related to the surface suspended sediment concentrations with coefficients of determination accounting for 71 percent and 68 percent of the variation in the data, respectively. Regressions with radiance data accounted for 36 percent (band 2) or less of the variation. Logarithmic transformations of either reflectance or sediment concentrations increase the coefficients of determination for MSS band 2 reflectance data to 81 percent. Regressions between the ratio of MSS band 1 to MSS band 2 reflectances and concentrations also accounted for 80 percent of the variation. An equation Log_e SS (mg/l) = 9.21R½+ 2.71R½2 + 8.45, where S is surface suspended sediment concentrations and R¹/₂ is the ratio of MSS band 1 to MSS band 2 reflectances, provided the best fit to the data with a coefficient of determination of 0.82. This equation is essentially the same as an algorithm proposed by Topliss et at. (1990), for estimating surface suspended sediment concentrations in Canadian coastal waters. These equations for Enid Reservoir and Canadian waters suggest that it may be possible to develop an algorithm for widespread use for estimating surface suspended sediments.     

THE OPTIMALITY OF CAPACITY SHARING IN STOCHASTIC DYNAMIC PROGRAMMING PROBLEMS OF SHARED RESERVOIR OPERATION1

ABSTRACT: This paper is concerned with finding an optimal allocation of water entitlements for each of two users of water who share a reservoir. Two instruments of allocation are considered. The first, release sharing, involves sharing the releases from the reservoir; the second, capacity sharing, is concerned with allocating to each user of water a share of inflows, reservoir capacity and leakage and evaporation losses. Stochastic dynamic programming problems of reservoir operation under each type of sharing arrangement are formulated. It is shown that the maximum discounted expected profit from reservoir operation over the life of the storage using capacity sharing is at least as large as that obtained using release sharing and that release sharing is not Pareto efficient.     

A MODEL OF THE BEHAVIOR OF pH DETERMINING PARAMETERS IN IMPOUNDMENTS1

ABSTRACT: A computer model capable of describing the behavior of pH-determining parameters in an impoundment is presented. The steady-state model, based upon principles of water chemistry, applies the complete-mix concept to the routing of the chemical quantities, alkalinity and CO₂ acidity. An iterative procedure is used to account for surface mass transfer of carbon dioxide. A fourth-degree polynomial is solved for the hydrogen ion concentration at each point of routed alkalinity and CO₂ acidity concentrations. Field data required to verify and apply the model are described, including an example application to the Loyalhanna Creek Reservoir.     

A MULTICOMPONENT MODEL OF PHOSPHORUS DYNAMICS IN RESERVOIRS1

The models available for simulating phosphorus dynamics and trophic state in impoundments vary widely. The simpler empirically derived phosphorus models tend to be appropriate for long-term, steady or near steady state analyses. The more complex ecosystem models, because of computational expense and the importance of input parameter uncertainty, are impractical for very long-term simulation and most applicable for time-variable water quality simulations generally of short to intermediate time frames. An improved model for time variable, long-term simulation of trophic state in reservoirs with fluctuating inflow and outflow rates and volume is needed. Such a model is developed in this paper representing the phosphorus cycle in two-layer (i.e., epilimnion and hypolimnion) reservoirs. The model is designed to simulate seasonally varying reservoir water quality and eutrophication potential by using the phosphorus state variable as the water quality indicator. Long-term simulations with fluctuating volumes and variable influent and effluent flow rates are feasible and practical. The model utility is demonstrated through application to a pumped storage reservoir characteristic of these conditions.