Introduction to Rainwater Harvesting

Rainwater harvesting is the process of collecting and storing rainwater for later use. For preppers, it provides a sustainable, self-reliant water source that can be invaluable in emergency situations. As interest grows in preparedness and living off-grid, rainwater harvesting is becoming an increasingly popular option.

The basic components needed for a rainwater harvesting system include collection surfaces like a roof, gutters and pipes to transport the water, storage tanks or cisterns, and a distribution system. Proper maintenance like cleaning gutters, inspecting tanks, and treating water is also essential for an effective long-term system.

Rainwater harvesting allows preppers to handle one of the fundamentals of survival - access to clean water. By harnessing rainwater, preppers can become less dependent on uncertain public utility water supplies and more self-sufficient.

Rainwater Harvesting Overview

Rainwater harvesting involves gathering rain and surface runoff, then storing that water for later use instead of allowing it to evaporate or run off site. The benefits of rainwater harvesting include:

Provides a sustainable, renewable source of water at low or no cost.
Can reduce household water bills and save money over time. A typical household's water bill can range from $30-$100 per month, so rainwater harvesting can lead to significant savings.
Promotes self-reliance by reducing dependence on public/private water utilities. This satisfies a prepper's goal of handling basics like water independently.
Water is readily available on-site for emergencies. Much more secure than distant streams or relying on continued municipal supply.

While rainwater collection has been practiced throughout history, it has seen renewed popularity due to environmental awareness and an interest in self-sufficiency. Compared to water from wells or municipal sources, harvested rainwater is generally pure and free of minerals, chlorine and other chemicals.

Reasons Preppers Utilize Rainwater Harvesting

There are many reasons rainwater collection aligns well with preppers' goals of emergency preparedness and self-reliance:

Provides access to water if normal utility service is disrupted. Ideal for grid-down scenarios.
Allows self-sufficient living at remote or off-grid sites by meeting water needs independently.
Reduces dependence on public/private water systems that may be uncertain in a crisis.
Can function completely off-grid without connections to main power and water grids.
Fits with sustainable living practices and a prepper's mindset of handling basics like water supply independently.

Rainwater Harvesting System Components

A complete rainwater harvesting system requires the following key components:

Collection Surface: Roof, awning, or other aboveground catchment area that gathers the initial rainfall.
Gutters & Downspouts: Transport rainwater from roof to storage tanks efficiently. Should be properly sloped.
Storage Tanks/Cisterns: Hold and store water until needed. Can be above or below ground.
First Flush Diverter: Removes initial dirt and debris by diverting first rainwater.
Pumps & Filters: Pump water from tanks to final use point. Filters remove sediment.
Pipes & Delivery System: Plumbing network that delivers water to end use points. Must be properly sized.
Overflow: Safely redirects excess water if tanks are full. Proper drainage prevents stagnant water.

Maintenance Tips for Optimal Rainwater Quality

To keep a rainwater harvesting system functioning properly over the long-term:

Inspect and clean gutters regularly, removing debris that can contaminate water. Recommended monthly.
Check storage tank screens and covers for any openings or gaps. Keep lids sealed. Inspect annually.
Use first flush diverters and pre-filters like sediment filters to remove particles.
Clean inside storage tanks annually to prevent dirt buildup. Scrub walls, drain fully.
Test rainwater quality every 6 months and treat/filter if needed. Check pH, bacteria levels.
Make any repairs quickly to prevent potential contamination issues.

How Rainwater Harvesting Enables Preparedness

For preppers seeking emergency readiness and self-reliance, rainwater harvesting offers many benefits:

Provides access to water if normal utility service is cut off, making it ideal for grid-down scenarios.
Allows living fully off-grid without relying on external systems for water.
Reduces dependence on main municipal water supplies that could become unreliable.
Saves money on water bills over the long run that can be invested into other emergency provisions.
Enables handling a basic need like water supply independently, satisfying a prepper's goal of self-sufficiency.

Choosing a Rainwater Harvesting System

When selecting a rainwater harvesting setup, there are several considerations including system types, storage options, local climate factors, quality parts, and ideal collection surfaces.

Rainwater Harvesting System Types

There are 4 main rainwater harvesting system configurations:

Above Ground: Storage tanks located above ground outside. Easier to access and maintain.
Below Ground: Underground cisterns buried on site. More protected but harder to inspect.
Attached: Integrated into building's plumbing system. Convenient but may require permits.
Detached: Standalone, separate from the building's water system. Simplest option.

Choosing Appropriate Storage Tanks

For storage tanks and cisterns, factors include:

Material: Fiberglass, polyethylene, concrete, metal, wood. Polyethylene is lightweight, affordable and durable.
Size: Larger capacity holds more water but takes up more space. Match to expected usage and rainfall.
Location: Above vs. below ground. Above easier to maintain but more visible.
Opaque: Prevents light and algae growth. Look for UV-resistant tanks.
Placement: Consider grading, drainage, overflow. Allow room for valves and accessories.

Factors of Local Climate and Environment

Local conditions impact rainwater harvesting plans:

Rainfall: Collection potential depends on typical volumes and patterns. Check regional averages.
Space: Area available on site for system footprint. Small lots limit size.
Soil: Suitability for excavation and underground tanks. Sandier is better.
Temperature: Risk of freezing and needed insulation. Climate determines material choices.
Codes: Building codes, permits, regulations. Research local requirements.

Quality Parts for Optimal Performance

High-performing components are recommended:

Gutters: Seamless aluminum or steel, no leaks, sized to meet water volumes.
Piping: UV-resistant PVC, NSF-approved for potable water flow.
Filters: Multi-stage to remove sediment, particles and pathogens.
Pumps: Durable, efficient, adequately sized for delivery rate. Consider power source.
Installation: Professionally installed for water-tight functioning.

Ideal Roof Types and Materials

For efficient collection, roofing choices include:

Metal or rubber roofs instead of shingles. Sleeker surfaces.
Avoid treated wood shakes prone to rotting.
Sloped roof directs water naturally. Flat needs interior drains.
Maximize surface area based on collection needs. More space = more water.
Smooth materials like metal provide greater runoff.

Calculating Rainwater Harvesting Potential

The amount of water that can be collected depends on key variables like rainfall, catchment area, system efficiency, and water demand. Some simple formulas and online tools allow preppers to estimate rainwater harvesting potential.

Key Variables for Rainwater Collection Volume

Rainfall: Total annual volume and monthly patterns in your location. Average ranges from 30-60 inches per year.
Catchment Area: Total square footage of collection surfaces like roof. Typical home is 1500-3000 sq ft.
Efficiency: System efficiency based on losses. Typically 50-90%. Newer systems tend towards 90%.
Daily Use: Household rainwater demand and conservation. Average is 60-100 gallons per day.

Rainwater Harvesting Calculation Formula

A common rainwater harvesting calculation formula is:

Rainfall (inches) x Catchment Area (sq ft) x Efficiency (%)

With 1 inch of rain on 1 sq ft equal to 0.6 gallons collected.

Calculation Examples for Harvested Rainwater

Some example rainwater collection calculations:

40 inches of rainfall on a 1500 sq ft roof with 80% efficiency = 28,800 gallons per year
30 inches of rainfall on a 2000 sq ft roof with 70% efficiency = 25,200 gallons per year
50 inches of rainfall on a 3000 sq ft roof with 90% efficiency = 81,000 gallons per year

Online Tools and Calculators

There are many free online rainwater harvesting calculators:

EPA's WaterSense Rainwater Harvesting Calculator
Texas Water Development Board's System Sizing Tool
NC State University's Rainwater Harvesting Design Tool
Vendor tools like RainHarvest Systems ROI calculator

Use Calculations When Designing System

Make calculations during planning to:

Right-size tank and system capacity. Don't undersize.
Determine if rainwater can meet all household needs.
Size gutters, piping, pumps to handle potential maximum volumes.
Plan for overflow and secondary water source if needed.
Set realistic expectations about how much you can harvest.

Installing Rainwater Harvesting Systems

Proper installation is key to an effective rainwater harvesting system. Hiring a qualified contractor provides expertise, but DIY is an option too.

Typical Rainwater Harvesting Installation Steps

The major installation phases include:

Select and prepare appropriate site for tanks and components. Consider access, drainage.
Build storage base and supports if above ground. Excavate underground tank pit.
Install gutters, downspouts, and underground piping system. Maintain slope.
Add pre-tank filtration, pump(s), valves and accessories like UV sterilizer.
Connect to end uses like irrigation system or indoor plumbing.
Inspect for leaks, disinfect system, test water quality. Confirm proper functioning.

Benefits of Hiring a Qualified Contractor

An experienced contractor provides:

Optimal system sizing and site selection. Considers factors like climate, roof size, and usage.
Earthworks experience for underground cisterns. Proper excavation.
Expertise working with tanks, plumbing, electrical, pumps. Installed to code.
Permit assistance and code compliance. Navigates local regulations.
Post-install maintenance guidance. Provides operation manuals and instructions.

Preparing the Site and Building Base

Site preparation steps:

Clear area of debris, vegetation, obstructions. Allow room for all components.
Level surface and add gravel base for stability. Prevents shifting.
For above ground tanks, build concrete slab, foundation, or blocks. Secures tanks.
For underground, excavate proper depth pit per tank size. Protects from frost.

Installing System Components

Installation process:

Place tanks/cisterns securely on base. Strap down. Check for level.
Mount gutters with correct 1/4 inch per 10 feet slope to efficiently direct flow.
Run schedule 40 PVC piping in trench to tanks. Use appropriate diameters.
Add pre-filter devices, pump(s), valves, overflow pipe.
Connect to end-uses like hose bibs or indoor plumbing. May require backflow preventer.

Completing and Testing New Rainwater System

Final steps include:

Inspect entire system thoroughly for leaks. Repair any drips or seeps.
Flush system and sanitize tanks before collecting water. Chlorinate if needed.
Test water quality and treat/filter if needed. Check pH, bacteria levels.
Make any final adjustments for optimal functioning.
Review maintenance schedule with contractor. Do a walkthrough.

Using Rainwater Safely

While rainwater is fairly clean, proper usage, filtration, and disinfection is important to keep rainwater safe for drinking and personal use.

Potential Risks and Contaminants

Possible contaminants include:

Roof debris, bird droppings, dirt. Introduced during collection and storage.
Pathogens from animal/human contact. Can enter through openings.
Air pollution absorbed into water. Less of a concern in rural areas.
Algae, bacteria from sun exposure during storage. More common in above ground tanks.

Proper System Operation

To optimize water quality:

Keep roof and gutters clear of debris with screens. Check monthly.
Inspect tanks frequently and repair any cracks. Look for openings.
Prevent overflows with proper drainage. Maintain slope away from base.
Use first flush diverters to remove initial contaminants.
Test frequently for bacteria and treat as needed. Check for odor and discoloration.

Filtration and Disinfection Methods

Treatment options:

Slow sand filters, carbon filters, sediment filters. Multi-stage systems preferred.
Ultraviolet (UV) light, chlorine/chloramine tablets, hydrogen peroxide.
Boiling water for microbial disinfection.
Reverse osmosis system for drinking water. Highly effective.

Comparison to Other Emergency Water Sources

Versus other sources:

Rainwater less prone to pathogens than lakes, streams, found water.
Provides more reliable access than distant rivers or ponds.
Less secure and convenient than a drilled well. Requires power.
Municipal supply best option if still functioning.

Safe Drinking Water Storage

For storage:

Use food grade plastic jugs or stainless steel barrels. Avoid used containers.
Clean/sanitize containers thoroughly first. Air dry upside down.
Store cool and dark. Limit opening containers. Keep lids tight.
Rotate stock and watch for expiration dates. Replace annually.

Rainwater Harvesting Laws, Codes and Permits

Rainwater harvesting regulations vary significantly across states and local jurisdictions. Permits are often required for indoor plumbing uses.

Federal Laws and Guidance

EPA promotes rainwater harvesting through guidelines and education.
No national rainwater harvesting standards currently.
State professional engineering requirements may apply.
Water rights differ regarding rainwater ownership after collection.

State and Local Regulations

Laws related to rainwater harvesting differ widely between states. Research thoroughly.
Permits usually required if using rainwater for indoor plumbing.
County health departments or environmental offices provide oversight in some areas.
Some states prohibit or restrict rainwater harvesting. Others encourage it.

When Permits and Inspections Apply

Outdoor drip irrigation vs. indoor plumbing use.
Size and type of cisterns. Above ground vs. below.
Connecting into existing building plumbing system.
Local authorities determine permitting requirements. Check early in process.

State Regulation Examples and Differences

Texas requires contractor license and permits for installed systems. More restrictive.
California often requires permits for urban rainwater harvesting.
Colorado has no state permit, but local jurisdiction rules apply. Depends on county.
Washington state limits indoor usage but permits outdoor irrigation. More lenient.

Researching Your Local Rules

Contact county health department and building code office.
Check state environmental or water agencies for guidelines.
Search for state rainwater harvesting manuals.
Ask local permit officials about requirements.
Review municipal codes for any restrictions.

Costs and Cost-Effectiveness of Rainwater Harvesting

A complete rainwater harvesting system typically costs $2000 to $30,000 or more depending on size, components, and labor. ROI is often 10-20 years.

Cost Ranges of Complete Systems

Basic above ground systems: $2,000 - $4,000
Larger underground cisterns: $15,000 - $30,000
Average $3 to $5 per gallon of storage capacity.
Just tanks $1 to $2 per gallon.
Professional installation adds 35% - 50% to overall cost.

Key Factors Impacting System Costs

Size, material, type of storage tanks. Polyethylene most affordable.
Above ground is cheaper than excavating underground.
Pumping, filtration/purification equipment needed.
Gutter and drainage modifications.
Professional vs. DIY labor. DIY saves significantly.

Return on Investment Evaluation

Payback periods typically range from 10-20 years.
Cost savings from reducing water bills. Estimate based on usage.
Compare to other emergency water supply options. More economical than trucking in water.
Consider value of water self-sufficiency. Peace of mind has value.
Factor in replacement costs over lifespan. Tanks last 15-20 years typically.

Price Comparison to Other Emergency Sources

Generally more expensive than drilled well. Higher upfront costs.
Cheaper than regular water delivery. Avoid delivery fees over time.
Comparable to large portable water bladders. More convenient.
More economical than bottled water depending on use. Saves plastic waste.

Tips for Controlling Costs

Start small with simple above ground tanks. Add capacity over time.
Shop sales and clearance for discounted tanks. Be patient.
Save on labor by installing yourself if experienced.
Stage project over time. Start with gutters and basics first.
Focus on essential components first. Upgrade filtration later.

Conclusion

For preppers seeking emergency preparedness and self-reliance, rainwater harvesting provides a sustainable, renewable, and independent water source. With appropriate planning and maintenance, harvested rain can supply all or a substantial portion of a household's water needs, aligning well with goals of self-sufficiency. Carefully considering factors like system types, storage tanks, catchment area, and costs allows preppers to implement an

Rainwater Harvesting Essentials for Preppers