Collecting rainwater is a smart, eco-conscious solution for water conservation, emergency preparedness, and homesteading. With minimal materials and some basic outdoor skills, we can create an efficient and effective DIY rainwater diverter using tarps and rope. This system is highly portable, cost-effective, and suitable for gardens, cabins, camping setups, or emergency situations.

Benefits of a Tarp-Based Rainwater Collection System

• Low cost and accessible materials

• Quick setup without plumbing or tools

• Customizable to any size or space

• Portable and reusable

• Ideal for remote locations without permanent structures

Materials Required for DIY Rainwater Diverter

To build a functional and sturdy rainwater catchment system, we will need the following:

• Heavy-duty waterproof tarp (8'x10' minimum size; larger for higher yield)

• Rope or paracord (50–100 feet)

• Carabiners or bungee cords (optional, for tensioning)

• Buckets, barrels, or water jugs for collection

• PVC pipe, funnel, or spout (optional, for guiding flow)

• Tent stakes or support poles

• Knife or scissors

• Grommet kit (optional for tarp reinforcement)

Step-by-Step Guide to Building a DIY Tarp Rainwater Diverter

1. Select an Optimal Location

Choose a location that has:

• Unobstructed sky exposure

• A gentle slope or the ability to create height variation

• Stable anchor points (trees, fence posts, poles)

• Proximity to your water collection containers

Ensure the area is free of contaminants like overhanging leaves, bird droppings, or pesticide-treated surfaces.

2. Install the Tarp as a Catchment Surface

The tarp will serve as the main rainwater catchment area. Secure it so it slopes downward toward one edge or corner where the water will be funneled.

Key guidelines:

• Use rope to tie each corner of the tarp to trees, poles, or structures

• Position the tarp in a tent-like A-frame, lean-to, or slanted flat configuration

• Adjust tension to avoid sagging, as pooling can cause overflow or structural failure

• The lowest point should be where water exits or drains

3. Create a Central Drain Point

To direct water into a container, create a drainage channel at the lowest point:

• Cut a small hole in the corner or edge of the tarp

• Insert a PVC fitting, plastic funnel, or short pipe section

• Seal with waterproof tape, silicone, or zip ties to prevent leakage

• Secure the funnel’s exit over your barrel, jug, or bucket

Alternatively, let water run directly off the edge into a wide-mouth collection bin.

4. Set Up Collection Containers

Place water-safe, food-grade barrels or buckets directly beneath the outflow point. Use dark-colored, closed-top containers to:

• Prevent algae growth

• Avoid evaporation

• Protect from mosquito breeding

Elevating the container slightly on blocks or pallets will help when using spigots or transferring water.

5. Improve Stability with Support and Anchors

Reinforce the setup with:

• Tent stakes at rope tie-down points

• Guy lines for high wind resistance

• Center pole or ridge line under the tarp to prevent sagging

• Side panels or small weights to reduce tarp flapping in wind

The more taut the system, the better the flow rate and efficiency.

Advanced Configurations for Higher Efficiency

Multi-Tarp Systems

Use multiple tarps feeding into a central gutter or PVC pipe for larger-scale water harvesting. This is ideal for:

• Cabins or tiny homes without gutters

• Greenhouses or off-grid gardens

Gravity-Fed Filtration System

Install a gravity-fed water filter downstream from the collection barrel to make water safe for non-potable uses like irrigation, cleaning, or even emergency drinking when combined with proper filtration.

First Flush Diverter

To reduce contamination, build a first flush diverter system:

• Diverts the first few gallons of rain, which carry dust, bird droppings, and debris

• Use a vertical pipe with a ball valve or a small bucket that overflows only after filling

Best Types of Tarps for Rainwater Collection

Tarp Type	Benefits	Notes
Polyethylene	Waterproof, lightweight, low-cost	Ideal for temporary setups
Canvas	Natural material, breathable, durable	Requires waterproofing treatment
Vinyl	Heavy-duty, UV-resistant, mold-resistant	Best for long-term or large-scale use

 

Choose a UV-treated tarp for long exposure and reinforced grommets for durability.

Estimated Water Yield from Rainfall

Use the following formula to calculate potential collection:

Gallons collected = Square feet of tarp x inches of rainfall x 0.623

For example, an 8'x10' tarp (80 sq ft) in a 1-inch rainstorm yields:

80 x 1 x 0.623 = 49.84 gallons

Multiply by the frequency of rainfall in your area to estimate monthly collection.

Practical Uses for Collected Rainwater

• Garden and plant irrigation

• Cleaning tools, boots, or outdoor gear

• Filling animal troughs

• Emergency sanitation or flushing

• Filtered drinking water (in emergency only)

Maintenance and Storage

• Rinse the tarp after each use to remove debris

• Check ropes for wear or fraying regularly

• Clean containers monthly with vinegar or mild bleach

• Store tarp dry and rolled to prevent mold and creases

Safety Precautions

• Never store water for drinking without proper filtration or purification

• Ensure containers are sealed to prevent mosquito larvae

• Use food-grade plastics only if storing water for animal or human use

• Keep system away from roof runoff contaminated with chemicals

Why This DIY Method Stands Out

The tarp-and-rope rainwater diverter is a versatile, scalable, and affordable method to capture natural resources without needing plumbing, hardware stores, or technical know-how. Its value lies in:

• Portability for camping and emergency use

• Simplicity for rapid deployment

• Scalability for homestead or survivalist applications

• Eco-friendly principles of reuse and self-sufficiency

Conclusion

Building a DIY rainwater diverter using tarps and rope empowers us to harness nature’s free resources while reducing dependency on utilities. With proper setup and maintenance, this solution offers tremendous value across homesteading, off-grid living, and disaster preparedness scenarios.

Whether you're prepping for emergencies or just watering your backyard garden, this easy yet powerful system gets the job done—with minimal cost and maximum impact.