Manual De Mediciones Hidraulicas

U. S. Department of the Interior

Bureau of Reclamation

WATER MEASUREMENT MANUAL
A WATER RESOURCES TECHNICAL PUBLICATION
Water Measurement web page

A guide to effective water measurement practices for better water management

U.S. Department of the Interior Bureau of Reclamation

In cooperation with

FIRST EDITION 1953 SECOND EDITION 1967 REPRINTED 1967, 1971 REVISED REPRINT 1974REPRINTED 1975, 1977, 1981 REVISED REPRINT 1984 REPRINTED 1993 THIRD EDITION 1997 REVISED REPRINTED 2001

For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, DC 20402. As the Nation's principal conservation agency, the Department of the Interior has responsibility for most of our nationally owned public lands and natural resources. This includes fosteringsound use of our land and water resources; protecting our fish, wildlife, and biological diversity; preserving the environmental and cultural values of our national parks and historical places; and providing for the enjoyment of life through outdoor recreation. The Department assesses our energy and mineral resources and works to ensure that their development is in the best interests of all ourpeople by encouraging stewardship and citizen participation in their care. The Department also has a major responsibility for American Indian reservation communities and for people who live in island territories under U.S. Administration.

PREFACE
The mission of many public and private water resources organizations is to manage and conserve existing water supplies. These management effortsinvolve making sound technical and economic decisions concerning new and existing water needs, while respecting the environment by sustaining or restoring the aquatic ecosystems which may be affected. One key to better management practices, including water conservation, is reliable and accurate water measurement. The term "water measurement" as used in this manual refers to the measurement of flow (unitvolume per unit time). Major advances in measurement technology along with a continued demand for the Water Measurement Manual are responsible for initiating this revision. The first edition of the Water Measurement Manual (1953) had a distribution of 11,000 copies and was compiled from the Bureau of Reclamation (Reclamation) publication Manual for Measurement of Irrigation Water (1946). Thisprevious manual had five earlier editions beginning in 1913 and extending to 1940. The continual demand for the Water Measurement Manual and the need for updating resulted in the second edition (1967). From 1967 to 1984, two revised reprints plus five reprints of the second edition were published. The demand and need for the second edition has continued because of conservation pressure and increaseduser competition for water; therefore, this third edition was prepared to supplement and update information contained in the second edition. Modern trends of technical practice, along with the developments in personal computers, have resulted in increased emphasis on using custom-fitted, long-throated measurement structures that can be designed to measure flow and are simpler to fabricate.Consequently, fewer short-form flumes are being considered for new installations. Thus, information on Parshall flumes has been reduced and incorporated in the more general "Flumes" chapter, which recommends longthroated flumes for new installation in preference to Parshall flumes. The main Parshall flume information retained in this edition relates to maintenance and operation needs of existing flumes,including flume dimensions, free flow measurement, submerged flow measurement, and head losses. The sections on size selection and setting crest elevation for Parshall flumes have been deleted or reduced in this edition. Where Parshall flumes may be desired or required by State law, examples in the previous editions of the manual can be referred to for size selection and setting the crest...