Category Archives: How-to

Concerned With Aesthetics of Above Ground Water Storage?

This is Part 6 in the series “How to Build a Rainwater Collection System”.  Click to see parts onetwothreefour and five.

Concerned With Aesthetics of Above Ground Water Storage?Are you concerned with the aesthetics of above ground water storage?  Then underground storage may be right for you.

Underground storage tanks need to be structurally engineered to withstand the inward pressures of back filling and compacting. Most will need to be weighted down so ground water will not “float” the tank when empty.  It is advised that a curtain drain be installed at bottom of excavation to allow excess ground water to drain away for the same reason.

Buried tanks can be fiberglass, plastic, and cement. Large sizes (over 2,000 gallons) tend to be fiberglass, while smaller plastic tanks (up to 2,000 gallons) can be manifolded together to achieve the desired capacity. Cement tanks should be lined with a poly liner and “mono poured” when constructed.

Other specialty tanks consist of modular which are may be buried and bladder or pillow tanks that can be placed in crawl spaces.

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How to Build a Rainwater Collection System – Part 5

This is Part 5 in the series “How to Build a Rainwater Collection System”.  Click to see parts onetwothree and four.

How to Build a Rainwater Collection System - Part 5Steel water storage tanks for rainwater collection are generally bolted together grain silos adapted for this use. Made of galvanized corrugated steel panels, wall panels average 17 – 20 gauge with the galvanized roof panels being high rib or flat seam with a center hatch at the top and an access hatch near the bottom of the roof. A felt pre-liner is used between the steel and the main liner to protect it from abrasion. Liners are usually polyethylene and NSF approved when used for potable application or PVC, which is generally used for non-potable. However, PVC can be used for potable, as long as it is NSF approved.  RainBank recommends polyethylene for this application.

Steel tanks need to be built on a engineered cement slab with hold-down anchor brackets designed for the seismic zone where the tank will be placed. Plumbing for overflow, suction, discharge and any cross over lines used in multiple tank applications can either be PVC flanges, polyethylene or PVC boots if coming up through the cement slab. If penetrating through the side of the wall panels, PVC flanges will need to be used.

How to Build a Rainwater Collection System - Part 5Steel water storage tanks offer durability and protection of the liner from UV rays, plus offers an industrial or rural architectural look. Many commercial applications use this type of storage for both of these reasons. Overflow lines can be installed on the outside of the tank, but it is recommended that any pressurized lines be underground and frost protected in our Washington climate.

Accessories include exterior ladders, platforms, and level gauges. The galvanizing does not need painting although if properly prepped, tanks can be painted to suit.

Assembly can be difficult for the homeowner or contractor, so it is recommended that a trained installer with the proper tools and knowledge be used.

Are you interested in building your own water harvesting system?  Leave a comment below.

What is the Best Storage Tank for my Rainwater Catchment System?

What is the Best Storage Tank for my Rainwater Catchment SystemThis is Part 4 in the series “How to Build a Rainwater Collection System”.  Click to see parts one, two and three

What is the best storage tank for my rainwater catchment system?

Rainwater from your roof needs to be stored for future use and there are many types and manufacturers of water storage tanks. Above ground plastic tanks are a economical way to store rainwater. Most potable plastic water tanks are made from Polyethylene and it is recommended that they be “tumble molted”.

What is the Best Storage Tank for my Rainwater Catchment System2Sizes vary from a simple 50 gallon rain barrel all the way up to 10,000 gallons. All should have a UV protection warranty for at least 8 years. Dark colors are recommended to alleviate light penetration which can cause algae growth. Multiple tanks can be manifolded together to achieve the volume of storage needed. Keep in mind that plumbing should be under ground for frost protection.

There are vertical cylinder plastic water tanks if you have a large area for storage. Slim line design plastic water tanks are best suited for urban settings where space is an issue. There are box type plastic water tanks for storage under decks.

All rainwater storage tanks should be NSF approved for drinking water, should you decide to go potable now or in the future. There is a tank that will fit every application.

In the next installment of this series, we will discuss steel tanks with poly liners.