Project: Komatke Area Drainage Master Study

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

Key Personnel: Brian Schalk – Project Manager; Hari Raghavan – Project Engineer/Technical Lead

Project Description: FLO-2D modeling of the Komatke Community, located in District 6 of the Gila River Indian Community, was conducted to help identify and mitigate flooding within the study area. The study area is approximately 23.4 square miles and was modeled with a FLO-2D grid comprised of square elements measuring 20’x20’, for a total of approximately 1.7 million grid elements. Modeling special conditions included: steep, mountainous terrain in upper watershed; alluvial fan landform at base of mountain; broad, unconfined flow through natural desert and residential and community development; roadway impoundment and a significant number of culvert crossings; local retention facilities and channels. FLO-2D model results were used to identify flood hazards based on flow depth and the product of flow depth and velocity. In addition, model results were used to identify potential regional flood mitigation alternatives. An alternatives analysis was conducted and three regional alternatives were selected for conceptual design and cost estimating. Public outreach was conducted at numerous Community Meetings with the goal being to identify flood prone areas and to convey project progress and results. Benefits from this detailed level of FLO-2D modeling include: updated, detailed reflection of existing hydrologic and hydraulic conditions throughout the study area; modeling results for development of flood mitigation alternatives; and capital improvement planning information to help quantifiably rate or prioritize the flood/drainage issues within the study area when comparing against other study areas.