Stormwater Resilience and Flood Risk Management
Lahaina Watershed Flood Control Project
“Incentivize 100% stormwater control and infiltration (with simple vegetative swales) to eliminate brown water events that impact our reefs and to recharge the aquifer...”
Community Quote from Long-Term Planning Recovery Survey
Purpose
This project will implement holistic stormwater and flood management, minimize stormwater runoff into the ocean and manage floodwaters across West Maui.
Project Description
Drainage Master Plan Update (to address localized flooding in urbanized areas of Lahaina) and preliminary design for the flood control project (retention basins and diversion channels mauka of Lahaina). This project is supported through U.S. Department of Agriculture (USDA) Natural Resources Conservation Service’s (NRCS) Watershed and Flood Prevention Operations Program. The County Department of Public Works (DPW) is the local sponsor with Stantec as contractor. The project is currently working on a supplementary environmental impact study since the original Environmental Impact Statement was written in the 1980s, and a hydrologic and hydraulic study. Once studies are completed, USDA NRCS and DPW will discuss the data, needs and how the Lahaina Watershed can address the needs through feasible conservation practices, either structural or non-structural.
Interdependencies and Roadblocks
This project aligns with the current effort to develop a watershed management plan for Kahoma and Kaua’ula watersheds. Currently there is a lack of sponsorship for NRCS projects. The current contract NRCS has is for roughly $1.4 million, but additional funds are needed. This project will have to compete nationally for design funding.
Next Steps
- Identification of funding source(s) and design
Project Details
Cost Estimate:
TBD
Existing Funding Sources:
Project Lead:
County Department of Public Works
Potential Funding Sources:
Watershed Protection Grants Program
Project Partners:
- County Department of Agriculture
- State Department of Health,
Surface Water Protection Branch - State Department of Land and Natural Resources, Division of Aquatics Resources
- U.S. Army Corps of Engineers
- U.S. Department of Agriculture, Natural Resources Conservation Service
- U.S. Environmental Protection Agency
Alignment with West Maui Community Plan (WMCP)
- Goal 2.1 Ready and resilient systems
- Action 1.38 Update the Lahaina Town Drainage Master Plan for Low Impact Development (LID) and develop an implementation plan
- Action 1.39 Support the implementation of flood control projects and siltation basins mauka of Honoapiʻilani Highway, including the remaining phases of the Lahaina Watershed project to address problem areas
- Action 1.40 Maintain a current inventory of drainage facilities in West Maui for use in developing long-term plans to address stormwater issues
- Action 1.41 Improve stormwater management systems along the Lower Honoapiʻilani Road to minimize stormwater runoff to the ocean