HIState-AdministeredSWPPP Requirements in Hawaii
Hawaii's construction stormwater program is administered by the Department of Health Clean Water Branch under Hawaii Administrative Rules Chapter 11-55. The state's unique geology, ecology, and climate create a compliance environment unlike any other US jurisdiction. Volcanic basalt and weathered volcanic soils—particularly the highly erodible red oxisols—mobilize extremely rapidly when disturbed, generating turbid runoff that can devastate coral reef ecosystems within hours of a rain event. Hawaii has some of the most sensitive receiving waters in the world, and the DOH CWB treats construction stormwater as a direct threat to coral reef health. Trade-wind patterns divide each island into windward (wet) and leeward (dry) zones with radically different storm frequencies and intensities. Hilo on the Big Island averages 130+ inches annually; the Kohala coast 30 miles away averages under 15. This means BMP design, inspection scheduling, and rainfall event thresholds must be calibrated for island-specific microclimates. Hawaii's NOI fees are among the highest in the US, and the state's four counties each impose additional grading permit requirements on top of the state NPDES program.
Hawaii SWPPP Key Facts
- ✓NOI fees are among the highest in the US—$500–$1,000+ depending on project size
- ✓Volcanic basalt soils (especially red oxisols) erode extremely rapidly when disturbed—turbidity controls are critical near coastal waters
- ✓Coral reef watershed protections apply statewide—virtually all coastal Hawaii discharges to reef-adjacent waters
- ✓Windward vs. leeward site classification dramatically affects BMP design and inspection frequency needs
- ✓Four county grading permit programs (Honolulu, Maui, Hawaii, Kauai) operate in addition to state NPDES
- ✓Trade-wind rain patterns create dramatic microclimate variation—Hilo averages 130+ inches/year while Kona coast averages under 15 inches
- ✓All construction materials and BMP supplies must be shipped by barge or air—plan 4-6 weeks for mainland-sourced materials
- ✓Hawaii's endangered species (Hawaiian monk seal, green sea turtle, native birds) trigger additional environmental review for coastal projects
Administering Agency
- Agency
- Hawaii Department of Health, Clean Water Branch (Hawaii DOH CWB)
- Phone
- 808-586-4309
- cwb@doh.hawaii.gov
Permit Details
- Permit Name
- Hawaii Construction General Permit
- Permit Number
- HI CGP (HAR Chapter 11-55)
- Effective Date
- 2019-08-01
SWPPP Thresholds & Triggers
- Acreage Threshold
- 1 acre of land disturbance, or less than 1 acre if part of a larger common plan of development
Coral reef watershed protections apply statewide—virtually all coastal construction in Hawaii discharges to reef-adjacent receiving waters. Volcanic basalt soils are extremely erodible when disturbed. Windward vs. leeward site classification significantly affects BMP design requirements.
Inspection Requirements
- Inspection Frequency
- At least once every 7 calendar days and within 24 hours of a qualifying storm event
- Rain Event Threshold
- 0.5 inch in a 24-hour period
- Certified Inspector
- Required by state
- Accepted Certifications
- CPESC, CESSWI, Hawaii DOH-approved erosion and sediment control training
Hawaii's trade-wind rain patterns create dramatically different conditions on windward vs. leeward sides of each island. Windward sites (e.g., Hilo, windward Oahu, Maui's north shore) receive 100+ inches annually with frequent qualifying rain events. Leeward sites (e.g., Kona, leeward Maui, Ewa Plain) may go weeks between events but face intense concentrated downpours when storms do occur. SWPPPs must be calibrated for island-specific and aspect-specific conditions.
Penalties & Enforcement
- Max Civil Penalty (Per Day)
- $25,000 per day per violation
- Criminal Penalties
- Criminal penalties under Hawaii Revised Statutes §342D for knowing violations
Hawaii DOH Clean Water Branch actively enforces coral reef protection. Sediment plumes reaching reef areas from construction sites have resulted in significant enforcement actions and consent agreements requiring remediation. High-profile coral bleaching events have increased political and regulatory pressure on construction-related turbidity.
Permit Fees
- NOI Filing Fee
- $500–$1,000+ (among the highest NOI fees in the US; verify current fee schedule with Hawaii DOH CWB)
- NOT Filing Fee
- $200+
- Other Fees
- Additional county grading permit fees in Honolulu, Maui, Hawaii, and Kauai counties.
How Hawaii Differs from Federal Requirements
- ⚠Hawaii NOI fees ($500–$1,000+) are dramatically higher than the $0 fee under the direct federal CGP.
- ⚠Coral reef watershed protections and volcanic soil erodibility create de facto additional BMP requirements not addressed in the federal CGP guidance.
- ⚠County grading permit requirement is a Hawaii-specific dual-permit layer with no federal equivalent.
- ⚠Hawaii's CZMA review for coastal construction adds a state-specific environmental review layer not required under the federal CGP.
- ⚠Endangered species consultation (Hawaiian monk seal, green sea turtle) for coastal projects can trigger Section 7 requirements that interact with stormwater permits.
SWPPP Tips for Hawaii
- ➤Submit your NOI early—Hawaii DOH CWB review can take longer than mainland states, and the higher fee requires payment processing before coverage is confirmed.
- ➤Design turbidity controls as your primary BMP, not secondary. Coral reef proximity means any visible sediment plume reaching coastal waters is an enforcement trigger.
- ➤Identify your site's windward vs. leeward classification before designing your SWPPP—a leeward Kona site and a windward Hilo site have fundamentally different BMP requirements despite being on the same island.
- ➤Engage county DPW for grading permits concurrently with your DOH NOI—the county and state processes are independent and run on separate timelines.
- ➤Order BMP materials 4-6 weeks before mobilization—Hawaii is entirely dependent on barge shipping from the mainland, and delays are common.
- ➤Use cinder and volcanic rock check dams instead of straw wattles where possible—locally sourced volcanic materials are better adapted to Hawaii's steep terrain and heavy rainfall.
Hawaii SWPPP FAQs
Why are Hawaii's NOI fees so much higher than other states?+
Hawaii DOH CWB uses permit fees to fund a robust inspection and enforcement program. The state's small size and high ecological sensitivity—particularly coral reef protection—justify a well-staffed regulatory program. Budget $500–$1,000+ for NOI fees and confirm the current fee schedule with DOH CWB before project budgeting.
How do coral reef protections affect my construction SWPPP?+
Virtually all coastal construction in Hawaii discharges to watersheds that drain to coral reef ecosystems. Turbid runoff from construction sites is a documented cause of coral bleaching and mortality. DOH CWB requires robust sediment and turbidity controls, and enforcement response to visible sediment plumes reaching coastal waters is swift.
Do I need a county grading permit in addition to the state NPDES permit?+
Yes. All four Hawaii counties (Honolulu, Maui, Hawaii, Kauai) require county grading permits for significant earthwork. These are administered by county Department of Public Works offices and are separate from the state NPDES HI CGP. Both must be obtained before grading begins.
What makes Hawaii's volcanic soils particularly challenging for stormwater management?+
Hawaii's red oxisol soils (derived from weathered volcanic basalt) have extremely fine particles that remain suspended in water for extended periods. Standard sediment basins and silt fence have difficulty capturing these fine particles. Flocculation agents, turbidity curtains, and enhanced settling systems may be needed, especially near coastal discharge points where turbidity is the primary compliance metric.
How does the windward vs. leeward distinction affect my SWPPP?+
Windward sites (northeast-facing slopes exposed to trade winds) receive frequent, sometimes daily rainfall. Your SWPPP must be designed for near-continuous wet conditions with robust permanent BMPs. Leeward sites receive far less rainfall but face intense, concentrated downpours during Kona storms and winter weather events. Leeward SWPPPs should focus on high-intensity flow management and rapid-deployment BMPs.
Are there additional environmental reviews for projects near the coast in Hawaii?+
Yes. Coastal projects may trigger additional review under the Coastal Zone Management Act (CZMA), Hawaii Environmental Policy Act (HEPA Chapter 343), and federal Section 7 consultation for endangered species (Hawaiian monk seal, green sea turtle). These reviews can add months to your pre-construction timeline and should be initiated early in project planning.
Find a SWPPP Consultant in Hawaii
Tell us about your project and we'll connect you with a qualified environmental consultant — free, no obligation.