WSP11570

• File Number: 8111.807
• Description: Arkansas River Compact Administration - Stream Gage Evaluation
• Basin: Arkansas
• Date: 1/1/1980
• Author: USGS
• Title: Cost-Effective Stream Gaging Strategies for the Lower Colorado River
• Water Supply Pro - Doc Type: Publication

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in stream-gaging activity in the Lower Basin by the Geological Survey.

Table 1 lists those stream gages in the Lower Basin that are considered

by the Geological Survey as being operated primarily in support of the

compact and subsequent legal interpretations of the Compact. The financial

scope of this network of stream gages is such that it warrants an analysis

of the effectiveness of the resulting data in the administration of the

compact.

PROBLEM STATEMENT

The multitude of uses that are made of the waters of the Lower

Colorado River would result in intractability if a complete economic

analysis of the worth of each stream gage were attempted. Therefore the

uncertainty or error in the estimation of annual discharges serves in this

study as an inverse surrogate for the economic worth of the data. Un-

certainty at a particular stream gage is expressed in this study either as

the variance of the error of estimate of annual mean flow past the gage or

its square root, the standard deviation. A unit of uncertainty is assumed

to be as deleterious at anyone stream gage as it is at any other in the

network. Therefore, the objective of this study is to devise strategies

for operating the network of gages that will minimize the total uncertainty

in the system for a given operating budget.

APPROACH

The uncertainty in the annual mean discharge at a stream gage is a

function of the frequency of visits that are made to the gage to service

the recording equipment and to make discharge measurements. Thus, for any

particular stream gage its uncertainty is minimized by visiting it as'

frequently as possible, which entails expending as much money and manpower

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