Best Materials for Rainwater Collection Systems?

Selecting the Right Tank Material

When it comes to selecting the right tank material for a rainwater collection system, there are several factors to consider. Food-grade plastic tanks are a popular choice due to their affordability and corrosion resistance. They come in a range of sizes, from 100 gallons to 10,000 gallons or more, making them suitable for residential and commercial applications. However, they may not be the best option for systems that require high water pressure or aggressive water chemistry.

Tank Size and Overflow Management

To manage rainwater overflow effectively, it’s essential to choose a tank size that’s proportionate to the roof catchment area. A general rule of thumb is to use a tank that’s at least 1/3 the size of the roof catchment area. For example, a 1,000 square foot roof would require a 333-gallon tank. Overflow management is critical to prevent water from spilling onto the ground and causing erosion. A first flush device can be installed to divert the first flow of water from the roof, which may contain debris and contaminants.

Other Materials and Considerations

In addition to food-grade plastic tanks, stainless steel and galvanized steel tanks are also suitable for rainwater collection systems. These materials are more durable and resistant to corrosion than plastic tanks, but they come with a higher upfront cost. Galvanized steel tanks are a good option for systems that require high water pressure, as they can withstand pressures up to 40 psi. When selecting a tank material, it’s essential to consider factors such as water chemistry, tank size, and overflow management to ensure a safe and effective rainwater collection system.