Harvesting Rainwater for Your Homestead in 9 Days or Less

1. Understand local regulations and rainwater safety basics

Rainwater harvesting is simple: collect the rain, store the rain, and use the rain.

Know your local laws. Before starting any rainwater harvesting project, research your state and local regulations. While no US state completely bans rainwater collection, some have specific restrictions or requirements. For example, Colorado allows residents to collect up to 110 gallons for outdoor use only, while Texas offers tax incentives for rainwater harvesting equipment.

Prioritize safety. Key safety considerations include:

• Keeping water away from building foundations
• Using safe materials for roofs, gutters, and tanks
• Protecting tanks from sunlight, insects, and animals
• Planning for overflow
• Ensuring proper weight distribution for full tanks

By understanding regulations and safety basics, you can confidently begin your rainwater harvesting journey while avoiding potential legal and structural issues.

2. Choose the right components for your rainwater harvesting system

Every rainwater harvesting system consists of the following: [catchment surfaces, gutters and downspouts, screens and filters, storage tank, storage tank foundation, storage tank vent, storage tank overflow, storage tank outlet, first-flush system (optional), pumps and indoor use filtration and treatment (optional)]

Essential components. A basic rainwater harvesting system includes:

• Catchment surface (typically a roof)
• Gutters and downspouts
• Screens and filters
• Storage tank
• Tank foundation
• Tank vent, overflow, and outlet

Optional components. Depending on your needs and budget, consider adding:

• First-flush system to divert initial, dirtier runoff
• Pumps for increased water pressure
• Indoor filtration and treatment systems for potable use

When selecting components, consider factors such as durability, compatibility with your existing structures, and ease of maintenance. For example, aluminum gutters are common and suitable for most applications, while more expensive options like copper can last longer but may require special considerations to prevent corrosion.

3. Determine your water needs and catchment potential

The size of your catchment area determines how much rain you'll collect regardless of rainfall.

Calculate catchment area. Use tools like Google Earth to measure your roof's surface area. This, combined with local rainfall data, will help you estimate your potential rainwater collection.

Assess water needs. Consider your intended use:

• Small garden (~100 ft²): 60 gallons/week
• Medium garden (~500 ft²): 300 gallons/week
• Large garden (~800 ft²): 500 gallons/week
• Indoor use: ~180 gallons/person/week

By comparing your catchment potential to your water needs, you can determine if rainwater harvesting is viable for your situation and what size system you'll require. Remember that actual collection will be less than theoretical due to factors like roof material and gutter efficiency.

4. Select appropriate storage tanks based on usage and budget

As big as your budget allows.

Tank options. Choose from various types based on your needs and resources:

• Rain barrels (40-80 gallons): $0-$100, ideal for small gardens
• IBC totes (275-330 gallons): $175-$350, good for medium gardens or small households
• Polyethylene tanks (100-20,000+ gallons): $400-$36,000+, versatile for various applications
• Metal tanks (80-100,000+ gallons): $1,200-$20,000+, durable and fire-resistant

Considerations:

• Space available
• Intended use (outdoor vs. indoor, potable vs. non-potable)
• Climate (freezing concerns)
• Aesthetics
• Long-term plans (ability to add capacity)

For most residential applications, start with a system you can manage and expand as needed. A 500-1,000 gallon tank is often suitable for a medium-sized garden, while 1,000-5,000 gallons may be appropriate for indoor use in a family home.

5. Implement proper filtration and treatment methods

If you do plan on drinking your rainwater, add a 5 – 10-micron filter right after your 10 – 30 micron filter.

Filtration levels:

• Coarse filtration: Gutter guards, downspout filters (leaves, debris)
• Fine filtration: 100-20 micron filters (sediment)
• Ultrafine filtration: 5-10 micron filters (for potable use)

Treatment options:

• UV disinfection: $600-$1,000, no byproducts, requires clear water
• Chlorine disinfection: $30-$50, inexpensive but potential byproducts
• Ozone disinfection: $250-$400, powerful but can be complex
• Countertop filters (e.g., Berkey): $200-$400, simple but limited capacity

Choose filtration and treatment based on your intended use. For outdoor, non-potable applications, basic screening and sediment filtration may suffice. For indoor and potable use, implement progressively finer filtration and consider a disinfection method to ensure water safety.

6. Install your system efficiently and safely

Pick a downspout, install the foundation, place the storage tank on the foundation, connect the downspout to the storage tank, route the overflow away from the adjacent building, configure the outlet and enable the rainwater to be used.

Installation steps:

1. Choose an appropriate downspout location
2. Prepare a level foundation (gravel pad, concrete, etc.)
3. Position the storage tank
4. Connect downspout to tank inlet
5. Install overflow pipe away from buildings
6. Set up outlet and any pumps or filtration systems

Key considerations:

• Ensure proper slope for water flow (1/8" per foot for horizontal pipes)
• Use appropriate materials (e.g., food-grade for potable systems)
• Install backflow prevention for pump systems
• Consider winterization needs in cold climates

For more complex systems or if you're unsure about any steps, consult a professional installer. Proper installation ensures system efficiency, safety, and longevity.

7. Maintain your rainwater harvesting system for longevity

To keep your system in tip-top shape, you'll need to maintain it.

Regular maintenance tasks:

• Clean gutters, downspouts, and inlet filters (after each rain event)
• Inspect tanks, pipes, and fittings for leaks or damage (monthly)
• Clean or replace filters as needed (follow manufacturer guidelines)
• De-sludge storage tanks (every 2 years)
• Service pumps according to manufacturer instructions

Seasonal considerations:

• Pre-rainy season: Clean roof and gutters, trim overhanging branches
• Winter: Winterize system in freezing climates (drain exposed pipes, protect pumps)

Water quality:

• Test water quality annually for potable systems
• Disinfect if contamination is suspected (1.5 fl oz liquid chlorine per 260 gallons)

By following a regular maintenance schedule, you can ensure your rainwater harvesting system operates efficiently and provides clean water for years to come. Remember, "low maintenance" doesn't mean "no maintenance" – a little consistent care goes a long way in preserving your investment and water quality.

Last updated: August 8, 2024