**VOLCANIC EVENTRAINWATER CATCHMENT CHECKLIST**

**VOLCANIC EVENTRAINWATER CATCHMENT CHECKLIST**
For Homes Dependent on Rainwater Catchment Systems
(Use during active ashfall and volcanic events)

IMMEDIATE ACTIONS — DURING ASHFALL1. Stop Roof Water Collection☐ Open the First Flush Diverter

• Diverts contaminated roof runoff away from the tank
  
• Prevents ash, tephra, and volcanic glass from entering storage
  
• Leave open until ashfall has fully ended and surfaces are cleared
  

☐ Disable any direct roof-to-tank inflow (if applicable)

2. Secure the Catchment Tank☐ Ensure tank cover is fully closed, sealed, and secured
☐ No gaps, tears, sagging, or water pooling
☐ Vents and overflows are screened and protected

3. Protect Household Safety☐ Stay indoors during ashfall
☐ Close all windows and doors
☐ Seal gaps with damp towels if ash intrusion occurs

SYSTEM PROTECTION — DURING & AFTER EVENT4. Pre-Tank Protection☐ Confirm pre-tank filter / debris barrier is in place
☐ Prevents roof and gutter contaminants from reaching the tank

5. Filtration Readiness☐ Expect filters to clog faster due to ash and tephra
☐ Replace filters as needed
☐ Keep spare filters on hand
☐ Avoid skin contact with contaminated water—tephra can cause irritation

6. After Ashfall Ends☐ Clear ash from roof surfaces and gutters before resuming collection
☐ Close First Flush Diverter only after roof is clean
☐ Inspect tank, filters, and system components
☐ Do not consume water if contamination is suspected—test if needed

REAL ESTATE & PROPERTY MANAGEMENT NOTEFor catchment-dependent homes, proactive water protection during volcanic events supports:

• Habitability and occupant safety
  
• Informed disclosure and due diligence
  
• Buyer confidence and defensible transactions
  

Provided by:
Uncle Tilo’s Clean Water & Hawai‘i Institute of Rainwater
Field-based education supporting safe, self-reliant rainwater harvesting
Your Water. Your Responsibility. Our Support.