WSP04351 - Laserfiche WebLink

Home Browse Search

. . 002252 Red River Boundary as detennined for this report until more precise in- formation has been developed. The areas involved are, for the most part, noncontributing. c. Noncontributing areas. Limited funds, time, and personnel have not permitted a precise detennination of noncontributing areas. Most of the noncontributing data were compiled from readily available information in the posseB~ion of agencies represented on the work group. These data had been compiled over, the years by the agencies for various purpose,s and to varying degrees of 'accuracy. The concepts of what consti- tutes noncontributing areas varies for individuals and intended purpose of use. It is not susceptible to precise definition because of judgment that must be used in detennination of what is "ordinary" rainfall periods and "how much" is partial run-off and similar items. However, for pur- poses of this report, it may be said that noncontributing areas are those areas that do not contribute surface run-off to a major river network. Areas that contribute surface run-off on~ during extreme rainfall periods are footnoted in this report as '~artially contributing during major storms" and are included under the noncontributing column. Such areas are identified on the inclosed maps and in tabulation by appropriate footnotes." The accuracy of most of the delineated noncontributing,areas is considered to be of rather low order. For this reason certain of the planimetric determinations were 'lllI1.deon the basis of use of ratio of noncontributing and contributing areas to the total drainage areas pre- viously published. Because of t,hiOmanner in which it has been necessary to develop noncontributing areas care should be exercised in their appli- cation. It should be considered of,a much lower order of accuracy than the other areas in the basins where there are no noncontributing areas. c