Sonoqui Wash Channelization

When a delineation of the Sonoqui Wash revealed that its 100-year flood plan covered 800 acres and affected 160 homes the Flood Control District of Maricopa County engaged Stanley Consultants to channelize the wash.

The project included reconstruction of six roadway crossings and numerous private driveways, as well as relocation of many water, sewer, electric power, natural gas, and communications utilities.  There was extensive coordination, both before and during construction, with other adjacent projects.

The dual-purpose project also contained a significant recreational element.  The wash was designed to serve as a major trail corridor with capabilities for equestrian use that link regional and local parks and recreational facilities.  There was no designated equestrian path to be constructed within the channel corridor so it was desirable for all slopes and surfaces to be as traversable as possible by horse and rider.  Loose riprap was chosen for the bank protection.  All riprap in the drop structures and along the banks was recessed below the finished channel surface by 12 inches and covered by a layer of native soil.  According to Maricopa County Flood Control District Project Manager Raj Shah, this is the first time he’s seen this technique to accommodate the special needs of equestrians.

Stanley Consultants conducted pre-design analysis, developed design plans, specifications and a cost estimate, and provided construction post-design services for the 4-mile-long earth flood control channel.  The channelization improvements mitigated flood hazards by essentially containing the floodplain within the project corridor.