Ever since I started watching the horrifying #LAWildfires and the apparent complete absence of any risk analysis and strategic planning, I've been trying to come up with a rebuilding strategy that would help mitigate the risk of a wildfire spreading to your house which was independent of government services.
On average, California receives approximately 200 million acre-feet of precipitation annually, of which about 65% (130 million acre-feet) is lost to runoff into rivers and the Pacific Ocean. This translates to an estimated 42 trillion gallons of rainwater flowing back into the ocean each year. Capturing even a small fraction of this volume could dramatically alleviate California’s water shortages.
The first part of my plan is to figure out how to harvest some of that rainwater for fire suppression, water supply, utilize swamp-cooling on warmer days and even potable use or garden use.
Designing an attic-based system that combines rainwater harvesting, fire suppression, water supply, and swamp cooling requires integration of multiple components. Below is a detailed plan for such a system:
1. Rainwater Harvesting System
- Roof Catchment: The roof should be designed or retrofitted to collect rainwater efficiently. Use a sloped, durable, and non-toxic surface like metal or tile.
- Gutters and Downspouts: Install wide gutters with fine mesh screens to prevent debris entry. Connect downspouts to a pre-filter system.
- Pre-Filtration: A first-flush diverter removes initial roof runoff containing dirt and debris.
- Storage Tank in the Attic:Insulated, high-capacity tanks (e.g., polyethylene or stainless steel) installed in the attic space.Ensure structural reinforcement to bear the tank’s weight (1 gallon of water weighs ~8.34 pounds).
2. Fire Suppression System
- Dedicated Fire Suppression Reservoir: Reserve a portion of the stored water specifically for fire suppression.
- Sprinkler System:Install heat-activated sprinkler heads throughout the attic and home interior.Connect the sprinklers to a high-pressure pump powered by electricity with a battery backup or solar inverter for reliability.
- Fireproof Tank Insulation: Protect the water tanks from high temperatures during a fire.
- External Access: Add a fire department connection point to allow external water injection.
3. Swamp Cooler Functionality
- Cooler Pads and Fans:Use water from the tank to saturate cooling pads in a swamp cooler unit located in the attic.Install energy-efficient fans to draw air through the wet pads and distribute cooled air into living spaces via ductwork.
- Pump System:A small pump recirculates water through the cooler pads. Excess water drains back into the tank or to a graywater system.
- Thermostatic Control: A thermostat automates swamp cooler operation during hot weather.
4. Water Supply for the House
- Filtration and Purification:Use a multi-stage filtration system (sediment filter, carbon filter, UV sterilizer) for potable water.
- Plumbing Integration:Connect the tank to the house plumbing system for general water use.Include a pressure pump and expansion tank for consistent water pressure.
- Overflow Management:Route tank overflow to a garden or stormwater system to prevent flooding.
5. System Automation and Monitoring
- Sensors:Water level sensors to monitor tank capacity.Temperature sensors to manage water cooling or heating needs.
- Control System:Centralized control panel for managing water distribution, swamp cooler operation, and fire suppression.Internet-enabled system for remote monitoring and alerts.
6. Safety and Maintenance
- Structural Reinforcement: Ensure attic flooring and roof trusses can support the added weight of the system.
- Maintenance Schedule:Clean gutters, pre-filters, and cooling pads regularly.Inspect pumps, sprinklers, and plumbing for wear.
- Backup Power: Install solar panels or a generator to power the system during outages.
Flow Diagram Summary:
- Rainwater Collection → Pre-filtration → Storage Tank.
- Storage Tank splits into:Fire Suppression Sprinkler System.Swamp Cooler with Pump and Pads.House Water Supply (Filtered and Purified).
This system offers an efficient, multi-functional solution for water management, fire safety, and cooling, tailored to sustainable and resilient living.
