Effect of Agricultural Drainage on Water Quality in the Humid Portion of the Pacific Northwest
Agricultural drainage first began in Washington around 1830 and in Oregon around 1840. The first efforts to drain soils for agricultural use began by constructing shallow ditches spaced...
Pond Water, Sediment and Crystal Chemistry
The chemistry of pond waters is characterized with respect to TDS, major solute species and trace elements. Similar chemical characteristics are presented for pond bottom sediments as...
Food-Chain Transfer of Trace Elements to Wildlife
Trace elements in agricultural subsurface drainage water may bioaccumulate in wildlife through their feeding on organisms living in evaporation ponds or other habitats that receive the...
Development of a Selenium TMDL for the San Joaquin River
The objective of this study is to devise a user-friendly, reliable method to calculate a screening-level 'Total Maximum Daily Load' (TMDL) for the San Joaquin River and similar western...
Subterranean Disposal of Irrigation Drainage Waters in Western San Joaquin Valley
Subsurface drainage waters in the western San Joaquin Valley of California are laden with selenium and other toxic elements and above-ground disposal creates a hazard problem (Letey et...
CPIVOT v 2.0 Center Pivot Analysis and Design Software
A micro-computer based software package is presented which can be used for hydraulic design and/or analysis of center pivot irrigation systems. The software is written in C and requires...
Flow Simulation for Surface Irrigation Design
Experience shows that even the most sophisticated and accurate computer models of the surface-irrigation process will not be widely used by design agencies unless they manifest a certain...
Streamflow Depletions for Water Transfers in Utah
All inter- or intra-state transfers of Utah water rights must be accomplished by application and receive the approval of the Utah State Engineer. This paper summarizes the engineering...
Streamflow Depletions Considered in Water Transfers
In the State of Colorado, streamflow depletions are defined as that amount of water diverted to beneficial use minus return flows to the stream system. This paper summarizes the engineering...
Streamflow Depletions Resulting from Ground Water Transfers
An application to move the point of diversion of a quasi-municipal ground water right from about 4.8 km to a second well about 0.3 km from a river channel was made in the Reno/Sparks,...
Soil Moisture Monitoring Using a Portable Capacitance Probe
Accurate monitoring of soil moisture has long been in integral part of a successful agricultural management system. Water has increasingly become a valuable and much sought after natural...
Availability Analysis of Irrigation Systems for Improved Management
Availability of an irrigation system is defined as the ratio of time of successful system operation to total desired operation time. Operation is successful when the flow rate of water...
Parameter Estimates for a Groundwater Model
This paper presents a parameter sensitivity study of a two dimensional flow and transport model of a contaminated site. Hydrogeological and site data from previous investigations were...
An Overview of Methods to Delineate Capture Zones of Pumping Wells
Rainfall over the surface area of an unconfined aquifer, which contributes flow to a pumping well under Dupuit conditions, was estimated. Using a two-dimensional analytical model with...
Regulatory Constraints on Vegetation Control in Channels, A Case Study of the Santa Ynez River, Santa Barbara County, California
The Santa Barbara County Flood Control and Water Conservation District has encountered difficulties in obtaining permits from state and federal agencies for vegetation control activities...
A Semi-Discrete Element Approach to the River Ice Breakup and Jamming Process
A semi-discrete element approach was developed to simulate the whole river ice breakup and jamming process. In this approach, ice mass is treated as discrete elements, and the movement...
Mechanism of Air Entrainment in Spillway Aerators
The mechanism of air entrainment in the Nappe over spillway aerators was investigated. Turbulence was identified as the main agent for aeration. It was found that Nappe underpressure influences...
The Influence of Slope and Surface Roughness on Trapezoidal Free Overfall Characteristics
The brink depth-discharge relationship for trapezoidal free overfalls was investigated including the effects of slope and roughness. The theoretical relationship is based on the momentum...
Performance of Prototype Aerating Weirs Downstream From TVA Hydropower Dams
TVA has constructed aerating weirs below certain of its hydropower dams to (1) increase tailwater dissolved oxygen (DO) content during generation, and (2) improve minimum flows between...
Flow Patterns in Constructed Wetlands
Wetland water flow is sensitive to evapotranspiration and rainfall, and to the internal configuration of substrates and biota. All wetlands are subject to significant dead zones and bypassing....
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