The normal impingement of turbulent circular jets on smooth walls is studied both experimentally and analytically. This type of flow can be divided into three distinct flow regions: the free-jet region; the impingement region; and the wall-jet region. The impingement region is the most important. It is shown that the impingement region occupies about 14% of the impingement height above the wall, whereas it extends about 22% of the impingement height radially. Semi-empirical methods to predict axail variations of velocity and static pressure are developed. Similarity of velocity and static pressure profiles is investigated and it is shown that these profiles are well described by the Gaussian error function. Variation of pertinent length scales are obtained empirically using dimensional analysis so that the time-averaged velocity and pressure fields in the impingement region can be predicted. A method to predict the wall shear stress in the impingement region is developed.

A methodology for examining design spillway floods for a series of dams is outlined using existing meteorologic and hydrologic data in continuous watershed modeling. Initially, a large complex watershed is subdivided into homogeneous hydrometeorologic subwatersheds where model parameters can be determined for each such subwatershed. Using continuous observed hourly precipitation, streamflow throughout the watershed is simulated and compared to the observed streamflow records. When a good comparison between recorded and simulated flow is achieved, the model is calibrated. Because the model has a physical basis and simulates the observed record, both low flows and peak floods, the extension to extreme hydrometeorologic events would be adequately modeled. The precipitation event studied was the probably maximum precipitation as defined by the National Weather Service. In the modeling of this event, initial snow and moisture conditions were examined to assess their effect on the resulting flood.

The invariant imbedding technique is used to find the unknown slope of the water table near the surface reservoir in a problem of unsteady ground-water flow into a surface reservoir in a large unconfined aquifer. The original nonlinear two-point boundary-value problem is transformed into an initial-value problem and an exact solution is obtained by the technique of quasilinearization. The invariant imbedding method involves no trial-and-error procedure and is easily programmed. This technique provides a useful tool in solving field problems and it becomes extremely powerful in solving a family of problems in which a set of unknown initial conditions are required to be determined from the corresponding given set of boundary conditions.

Bloomsberg's equation for the description of surface runoff hydrographs is modified and a methodology is developed to express the shape and profile of rising limb, crest segment, and recession limb of a hydrograph in algebraic terms. Variables of concern for such a description include time to peak, peak rate of runoff, point of recession, recession constant, and the percentage ratio of flow volumes in recession to the total volume of surface runoff. A computerized procedure, based on the derived formulations and working rules, would facilitate tracing of the surface runoff hydrograph free of reliance on graphical procedures. The method is applied to nine arbitrarily chosen drainage areas in the Great Basin region in order to investigate the reproducibility of observed unimodal flood hydrograph events.

Oscillations in surge tanks are analyzed by an extended application of Prasil's formula. Surge tanks with expansion chambers and throttled surge tanks are also considered. Approximate solutions for determining maximum elevations of upsurges and downsurges in simple tanks and in the spilling surge tanks are obtained.

Some applications are presented of a mathematical model concerning water hammer and release of dissolved gas in pipelines in the case where the pressure drops to the vapor pressure of the liquid transported. Column separation and cavitation in extensive parts of the pipeline, referred to as cavitating flow, are dealt with. A smoothing procedure is adopted in order to suppress nonlinear instability. Gas release is found to cause some damping of pressure waves in cases where only cavitating flow occurs. Gas release at a column separation cavity tends to increase the duration of column separation, whereas gas release in a possible cavitating flow region adjacent to the separation diminishes this duration, thus causing considerable damping of pressure peaks following subsequent column separations. Good agreement is obtained with experimental results available in the literature. Further experimentation is required as regards the parameters on which gas release depends.

Water resource projects within the same watershed basin must be operated in coordination with each other to assure the most efficient utilization of the available water supply. Within the Central Valley Basin of California, there are over 50 agencies responsible for the operation of 100 significant reservoirs and appurtenant facilities. Fortunately, two of the principal projects in the Basin, the Bureau of Reclamation's Central Valley Project and California Department of Water Resources' State Water Project, are operated in a coordinated manner through a formal written agreement. As multipurpose projects, each has similar objectives which include irrigation, flood control, power production, water quality control, navigation, fishery and wildlife protection, and recreation. With the growing demands and changing priorities for water, it is not only paramount that today's water manager have the technical experience but also an understanding of human relations.

The field manager of a water resource must stay current with changes in water supply, water uses, and water quality. Today's demands on the water supply in the San Joaquin Valley exceed the available supply which must be managed to meet the demands of all interests to the greatest extent possible. To accomplish this, methods of forecasting the supply must be refined. Waste of the resource must be eliminated by managing available storage or developing new storage methods. The importance of all uses must be recognized by all interests. Management philosophy will have to develop this. The nation's energy crises demand the utilization of this source of energy. The recreational needs of the country have to be expanded and the food production capacity of the nation is dependent on available water. Good management of water resources includes all the needs of the nation's people.

The management of the Central Valley Project in California is described. Organizational changes are analyzed and summarized. The management philosophy in the project's operations office is attuned to the complexities arising from technical and human involvement. Technical aspects of decision making are reviewed. The management of project operations is based upon organizational development theory. The paper illustrates that there is more to the successful implementation of contemporary management of river-basin operations than the design and use of mathematical models. The complete management system must account for the quality of the data and the goals and expertise of the people responsible for collecting and using the data. The development of modern river-basin management must be concerned with development of people as well as the creation of an efficient operating mechanism.

Factors affecting water resource planning are changing rapidly. In response to these changes, the Bureau of Reclamation is embarking on a total water management planning study in the Central Valley, California. Many water projects and facilities in this area have been constructed and operated to meet needs that are not entirely compatible with today's needs. The total water management approach to planning is an attempt to blend full consideration of environmental and social factors with full consideration of all alternative actions that might be reasonably possible for future project operation and development. The approach used in this process will entail exploring several specific study items or alternatives for study related to various aspects of water resource development in the Central Valley, some relating to the Central Valley Project specifically, others of wider interest.

Metagame analysis is an operations research technique that reconstructs classical game theory on a nonquantitative basis to analyze real world political conflicts. Since water management problems ultimately require a political decision, the metagame analysis algorithm can be used to solve water resources problems. A quantitative optimization method, integer programming, is integrated with the political (i.e., metagame) analysis so as to arrive at a solution to a dam allocation problem that is not only technically and economically feasible, but also politically feasible.

Procedures and computational techniques have been developed to facilitate the planning and the optimal sizing, sequencing, and timing of multiple-purpose, multiple-facility water resource developments. The procedure which is described and applied in this paper alleviates this curse of dimensionality by the use of an iterated linear programming-dynamic programming routine. It is characterized by an efficient linearization of the system relationships (to any accuracy desired), reservoir and generating plant sizing against an extended period of subnormal reservoir inflows typical of the stream critical periods, low computer time requirements, and high flexibility in testing the effects of added or changed system constraints. Description of the technique centers about, but is not limited to, a situation in which future water and power demands up to a time horizon are specified, so that the overall optimization criterion is to minimize the present worth of total project costs.