Rock Riprap Design Guidance
Rock riprap is a layer of loose rock used to protect soil from the erosive or scouring flows of water. Rock riprap is sometimes used for bank protection or bed stabilization in stream restoration projects where other erosion control techniques are not appropriate.
Key Contact: Clayton West, P.E., Supervising Engineer, 512-578-5150
Design Criteria
In order for the rock riprap to properly function, installing rock of good quality and the proper size gradation is important. Design criteria for rock riprap are listed in the Environmental Criteria Manual, Section 1.4.6. Look for subsection D. Rock riprap materials and construction methods are described in the City of Austin Standard Specification 591S.
Austin Watershed Protection recommends a field gradation test method for use during construction projects to verify that the specified rock will be installed. However, engineers may use an alternate preferred method conforming to Environmental Criteria Manual Section 1.4.6.
