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Stormwater Management Program
Stormwater runoff occurs when precipitation flows over the land and impervious areas such as paved streets and parking lots. Storm drainage systems are designed to decrease flooding by carrying storm water runoff through drains and underground pipes to nearby streams and eventually the ocean. Storm drainage systems generally do not provide treatment of stormwater runoff so it is important to keep pollutants out of our stormwater before reaching surface waters, such as our rivers and ocean.
The County of Maui works in many ways to protect stormwater and surface waters from pollutants that could negatively impact surface water quality. The County’s goal is to work with community individuals, businesses, large landowners, and State and Federal agencies to foster joint responsibility and positive action to protect our precious surface water resources.
The County of Maui works in many ways to protect stormwater and surface waters from pollutants that could negatively impact surface water quality. The County’s goal is to work with community individuals, businesses, large landowners, and State and Federal agencies to foster joint responsibility and positive action to protect our precious surface water resources.
The County’s MS4 NPDES Permit
The 2010 US Census identified Kahului-Pā‘ia as an urbanized area (UA) based on residential population. The boundary of the UA generally includes all of Kahului and Wailuku extending south to Waikapū and from Wai‘ehu to Pā‘ia along the windward coast. The UA designation triggers a requirement for a municipality to obtain a National Pollutant Discharge Elimination System (NPDES) permit for discharge of stormwater from their Small Municipal Separate Storm Sewer System (MS4). The County received their Notice of General Permit Coverage (NGPC), File No. HI 14KE360, for discharges from the MS4 in the UA from the State Department of Health (DOH) in April 2014. This NGPC expired at midnight, December 5, 2016 because of the expiration of DOH’s NPDES General Permit for Small MS4s (Appendix K). The County submitted a Notice of Intent (NOI) to DOH for the Renewal of the NGPC. DOH granted an Administrative Extension to the County’s current NGPC until DOH issues a new General Permit.
National Pollutant Discharge Elimination System (NPDES) Permit
- County of Maui Notice of General Permit Coverage (NGPC) Opens a New Window.
- Administrative Extension of COM Notice of General Permit Coverage (NGPC) Opens a New Window.
- HAR 11-55 - Appendix K Opens a New Window.
- UA Map
Storm Water Management Program (SWMP) Plan for the Kahului-Pā‘ia Urbanized Area
The County submitted their Storm Water Management Program (SWMP) Plan in August 2014 to the DOH. The SWMP Plan was revised in December 2015 to reflect information gained during initial implementation of the program. The purpose of the SWMP is to implement programs and practices to control polluted stormwater runoff from the County’s regulated MS4.
SWMP Components
- Introduction Opens a New Window.
- Public Education and Outreach Opens a New Window.
- Public Involvement / Participation Opens a New Window.
- Illicit Discharge Detection and Elimination Opens a New Window.
- Construction Site Runoff Control Opens a New Window.
- Post-Construction Runoff Control Opens a New Window.
- Pollution Prevention/Good Housekeeping Opens a New Window.
- Tables Opens a New Window.
- Figures Opens a New Window.
- Attachments A-F Opens a New Window.
What You Can Do
We can all do our part to protect stormwater and our valuable surface water resources by evaluating our own everyday activities and taking precautions to prevent pollution from entering storm drains. Click through the following documents for information and tips to keep our island beautiful.
- Soap Selection Info Sheet
- A Resident’s Guide to Protecting Stormwater Opens a New Window.
- Keiki Activity Booklet - Clean Water Warriors Opens a New Window.
- Care for the Land and Water Opens a New Window.
- Erosion - It's Soiling our Waters Opens a New Window.
- Discharging Swimming Pool Water Opens a New Window.
- Allowable Non-stormwater Discharges Opens a New Window.
Opens a New Window. - High Street Journal Articles Opens a New Window.
Resources for Teachers and Parents
We all depend on water every day and yet many of us don’t know where it comes from or the possible routes storm water can take from our homes to the ocean. Knowledge of storm water can increase our appreciation of the watershed we live in and the impact we have on it. Teachers and parents can use these fun lesson guides for their students and children to help them broaden their knowledge of storm water and the simple acts we can take to prevent pollution.
- How to Build Your Own Rain Barrel
- Rain Garden Activity
- Nonpoint Source Pollution Awareness: Word Search Puzzle
- The Clean Water Warrior Activity Book
- Nonpoint Source Pollution Awareness: What’s Wrong with This Picture?
SWMP Complaint Reporting Form
Stormwater Concern Reporting
Illicit discharge is any disposal, either intentional or unintentional, of material(s) or waste(s) that can pollute stormwater. You can report illicit discharges or spills to stormwater or surface waters in any of the following ways:
- Contact the Department of Public Works Highways Division (808) 270-7869;
- Via Email Opens a New Window. Opens a New Window. or;
- If you see illegal dumping or large spills that could contaminate surface waters or threaten public health, dial 911.
Stormwater Management Practices
Additional Resources
For additional information about stormwater or the MS4 permit program, please visit the links below.