River Mechanics Design Procedures in Maricopa County

About the Program

Category: County Resiliency (Best in Category)

Year: 2015

River mechanics is a critical design element for many flood control projects in Maricopa County, Arizona. It is an integral part of flood control and transportation projects such as dams, levees, bridges, open channels, and culverts, and play an important role in permitting processes for floodplain use, right-of-way, sand/gravel mining, and drainage permits. River mechanics is a complex subject and involves total scour, lateral erosion, sediment yield for dams/detention basins, levee toe-down design, etc. Prior to September 2013, Maricopa County and local cities (Phoenix, Mesa, Scottsdale, etc.) did not have river mechanics design procedures. Because different engineers might use different guidelines from different sources, the river mechanics designs were inconsistent and error-prone. Recently, the Flood Control District of Maricopa County (District) developed comprehensive and consistent river mechanics design procedures which were approved in September 2013. Since the approval, almost 300 river mechanics reviews have been performed by using these procedures on almost $40 million worth of capital improvement projects and a number of permit applications. These river mechanics design procedures are more consistent, accurate, and efficient, which allows Maricopa County and local cities to build safer and more cost-effective flood control projects and reduce the permit review time.