FHWA Resource Center
GEOTECH & HYDRAULICS TEAM
Hydraulic Engineering Circular No. 20, 3rd Edition
STREAM STABILITY AT HIGHWAY STRUCTURES
Publication No. FHWA-NHI-01-002
March 2001
ABSTRACT:
Stream Stability at Highway Structures, Hydraulic Engineering Circular No. 20 (HEC-20), provides guidelines for identifying stream instability problems at highway stream crossings. It is a dual unit update of the second edition published in 1995. The HEC-20 manual covers geomorphic and hydraulic factors that affect stream stability and provides a step-by-step analysis procedure for evaluation of stream stability problems. Stream channel classification, stream reconnaissance techniques, and rapid assessment methods for channel stability are summarized. Quantitative techniques for channel stability analysis, including degradation analysis, are provided, and channel restoration concepts are introduced.
There are two companion documents, Evaluating Scour at Bridges (HEC-18) and Bridge Scour and Stream Instability Countermeasures (HEC-23). These three documents contain updated material from previous editions and the publication Interim Procedures for Evaluating Scour at Bridges issued in September 1988 as part of the FHWA Technical Advisory T 5140.20, Scour at Bridges. T5140.20 has since been superseded by T5140.23, Evaluating Scour at Bridges dated October 28, 1991.
DOCUMENT AVAILABILITY:
To download an electronic copy:
RELATED NHI TRAINING COURSE:
FHWA-NHI-135065, Introduction to Highway Hydraulics
FHWA-NHI-135081, Introduction to Highway Hydraulics Software
RELATED SOFTWARE:
Visual Urban – Urban Drainage Design Programs (2002)
FHWA TECHNICAL CONTACTS:
Mr. Jorge Pagán-Ortiz
Sr. Hydraulics Engineer, FHWA Headquarters
Phone: (202) 366-4604
Email: jorge.pagan@fhwa.dot.gov
Dr. Larry Arneson
Sr. Hydraulics Engineer, FHWA Resource Center
Phone: (720) 963-3200
Email: larry.arneson@fhwa.dot.gov
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