Rainwater Harvesting: How Our System Provides a Resilient Water Supply for Sustainable Farming

A consistent supply of clean water is fundamental for farming. In fact, the agriculture industry consumes more water than any other industry. Sources for water vary by location, but many local farms rely on a combination that includes groundwater (typically accessed by tapping into an aquifer with a well), surface water (such as water collected from a drainage pond), and a municipal water supply. 

Since 2014, we have depended on groundwater from an on-site well to meet our water needs. However, increasingly inconsistent precipitation patterns due to climate change highlighted the opportunity to for additional, sustainable water sources. Last year, our rainfall data revealed dramatic shifts, with a dry spring requiring heavy well usage, followed by an extremely wet summer that oversaturated our fields and created problems with our fall planting schedule.

Actual monthly precipitation in 2024 versus historic average.

What Is Rainwater Harvesting?

Rainwater harvesting–also known as rainwater catchment or rainwater reclamation–is the process of collecting, storing, and using rainwater for various purposes instead of allowing it to run off. It typically involves capturing rainwater from surfaces like rooftops, filtering it to remove debris, and storing it in tanks or cisterns for future use. This method can be used for agricultural irrigation, flushing toilets, washing clothes, landscaping, or even drinking water when properly treated.

Rainwater harvesting is an eco-friendly solution to conserve water, reduce dependence on groundwater, and manage stormwater, making it particularly useful in areas with irregular rainfall or water shortages. It’s an ancient practice that regained popularity globally due to its sustainability and cost-effectiveness. While farms have long utilized this technology, it is now common in urban planning. Many new buildings in countries like China and Brazil feature rainwater systems, and it’s a requirement for all new construction in Tamil Nadu, India. Rainwater harvesting systems are also popular in island nations where access to freshwater is limited.

Our Rainwater Harvesting System

Last month, we completed a custom rainwater harvesting system, a multi-year project aimed at creating a resilient, sustainable water supply. With a 31,000-gallon capacity, the system reduces our dependence on groundwater and helps manage stormwater during flash floods.

How Our System Works

1. Rainwater Collection with Solar Panels

• Solar Panel Roof: The slanted, solar-paneled roof of our Container Barn serves as the collection surface. Solar panels provide a smooth and efficient medium for rain capture.

• Stainless Steel Water Catchment Gutter: A 60-foot stainless steel gutter spans the roof’s edge, collecting rain and snowmelt.

• Downspouts and Vortex Filters: Water flows through downspouts on each end of the gutter into vortex filters, which spin the water through a sieve to remove debris down to 100-200 microns.

2. Efficient Storage: 31,000-Gallon Rainwater Capacity

• Galvanized Steel Cisterns: Our system includes three galvanized steel cisterns with a total capacity of 31,000 gallons. This volume of storage increases our resilience in times of drought.

  • Twin Small Cisterns: Each holds 2,015 gallons and collects water from the downspouts. Underground pipes connect them for balanced filling.

  • Large Cistern: The 27,000-gallon main tank stores water for non-potable use. It features a float valve that triggers pumps in the smaller cisterns to refill it as needed.

3. Advanced Rainwater Filtration: Ensuring Safe, Usable Water

• Filtration and Sterilization: In the pump room, water undergoes a three-stage filtration process, including 5-micron debris filters and UV sterilization to eliminate pathogens.

• Plumbing: Filtered water is distributed to toilets, washing machine, hose bibbs, and wash basins. Potable fixtures (e.g., hand sinks, kitchen appliances) remain connected to well water.

• How much water will we harvest?

  Based on our roof’s surface area, we expect to collect approximately 77,760 gallons of rainwater annually.

• What happens if it doesn’t rain?

  Our pump room includes a bypass system, allowing us to switch to well water for all fixtures or refill the large cistern when needed.

• What happens if it rains too much?

  All cisterns have overflow outlets to safely release excess water.

• Is the water safe?

  Yes. The system uses advanced filtration and sterilization, and we regularly test both well and rainwater to ensure safety.

• Who designed the system?

  The system was a collaboration between REdesign.build, the architect and builders behind our Container Barn, and Rainwater Solutions, a Raleigh-based rainwater harvesting specialist.