Drainage Design Manual - the City of San Luis Obispo

Step 4 Project Approval and Permitting:Determine if project can be submitted as part of City or County Annual Work Plan,(AWP) associated with the Stream Management and Maintenance Program -IndividualPermit; if not initiate permitting with the following:Corps of Engineers Sect. 404 PermitRegional Board Water Quality CertificationFish & Game Stream Bed Alteration agreementReview for compliance with City/County Policies and RequirementsCEQA review and complianceLocal Grading/Building PermitsStep 5 Construction DrawingsSubmit Construction Drawings for Plan Check review; revise as necessaryStep 6 Construction Inspection & MonitoringInspection by project engineer and City or County Building/Public Works InspectorStep 7 Post Construction Maintenance and MonitoringMonitor project for erodibility/stability maintenance needs and conformance withmitigation requirements.Biological inspection/monitoring for permit conditions and mitigation requirements.6.5.2 Detailed Design ProceduresStep 1 - Site Evaluation and AnalysisProblem IdentificationA bank repair project design must address the fundamental and underlying problems responsiblefor the failure, or the project will be prone to failure at some time in the future. This includesidentification of both the probable cause of failure and the mode of failure. Stabilization designsthat are imposed as a solution on a site without this understanding could transfer the problem tothe other side of the channel, shift it upstream or downstream, or result in failure and/or costlyon-going maintenance. In addition, designs that impinge into the channel can cause localbackwater flooding effects. These consequences should be anticipated and evaluated prior toproject design, and the design modified to reflect these circumstances, and is a reference forgeomorphic analysis: http://www.fhwa.dot.gov/bridge/hydpub.htmTypically, causative factors are grouped according to whether they are from: (1) regionalhydraulic forces such as high shear stresses and altered runoff patterns, and consequent channelincision; (2) local hydraulic forces such as from a fallen tree trunk diverting flow against thebank, or other problems from sediment or debris accumulation; or (3) geotechnical instabilitiessuch as soft or weak bank soils, and/or prolonged channel bank saturation. Most often severalSLO Creek Drainage Design Manual 55 February 2003