Sacaton Area Drainage Master Study

Project: Sacaton Area Drainage Master Study

Client Name: Gila River Indian Community, Land Use Planning and Zoning Department

Key Personnel: Brian Schalk – Project Manager. Hari Raghavan – Technical Lead; Ed Kern – Project Engineer

Project Description: The Sacaton Area Drainage Master Study (ADMS) was completed to provide the Gila River Indian Community (Community) a detailed depiction of the existing drainage/flooding conditions within the study area. Study results were used to develop, assess and select viable flood hazard mitigation alternatives at the regional, semi-regional, and local levels and to recommend local drainage improvements to existing facilities. Study results will be used by the Community in the future in support of Community-led initiatives, such as home site development and plan and design of future drainage infrastructure. General tasks completed for the study include: data collection; field investigations; development of an existing condition two-dimensional (2-D) hydrologic and hydraulic (H&H) model (FLO-2D); mapping of flood hazard and flood risk areas; development of flood mitigation alternatives; conceptual plans and cost estimates for recommended regional flood mitigation alternatives; public and stakeholder outreach; and preparation of the Technical Data Notebook (TDN).The total FLO-2D modeled area was approximately 910 square miles, which is subdivided into 11 different computational domains (sub-models). The overall modeled area includes the contributing area associated with McClellan Wash, which is approximately 830 square miles at the confluence with the Gila River. Grid cell sizes for the various computational domains ranged from 10’x10’ in the Sacaton vicinity to 100’x100’ for the McClellan Wash contributing area. A total of 8.1 million grid elements comprised the fully modeled area.