FAQs 2 — Enchanted Gardens

1. Most rain catchment and storage systems described on internet are complicated, bulky and expensive to build due to too many requirements and considerations. For remote (hard to reach) regions, a drastically simplified and distributed low cost system was proposed, implemented, studied and improved over past 18 months at EG sites.

This article outlines the key features of such a low cost system. (Fig.1)

2. frame set: 10' by 10' by 6' (based on your need) straight canopy frame using 3/4" metal pipes. basic set latest price $146 (frame with 10' poles, tarp, bungee cords. excluding foot anchor weights.) 1" metal pipes and connectors would cost more.

Reference: https://ezcorners.com/pl.asp

An adjustable vertical pole system is shown in Fig.2. the top frame and upper vertical poles (2.5' length) are 3/4" pipes for low cost. The lower vertical poles (5' length) use 1" pipes for mechanical strength. Hose clamps are used to adjust and fix overall vertical height. The standard pipes are 10' in length (included in set price), so 5' cuts and 2.5' cuts (free cutting) are most cost effective.

If 2 or 3 catchment systems are desired, 10' by 20' or 10' by 30' frame set can share the common frame pipes and connectors of neighboring 10' by 10' frame set, with reduced cost per unit.

3. water storage: standard 250G, 275G, 300G, 330G IBC totes can be used all with different dimensions. The 275G tote may be most common. Used IBC totes are frequently available on Facebook marketplace, with pricing varying from $100 or $150 or higher, not including delivery. Empty IBC tote is not heavy and can be moved by 2 persons easily. For irrigation use (not for drinking without extra filtration), any prior usages of food stuffs, detergents or ethanol, can be easily cleaned and repurposed.

Note: the valve threads can be all different from tote to tote, so be patient in finding the correct adapter to convert to easy to use faucet. The primary tote must be directly under the center of the tarp, the base of the tote may need to be raised using concrete blocks to allow easy usage of the faucet. During the raining season, the rain collected may be more than can be used, so an optional secondary tote may be placed next to the primary tote, and divert water from primary tote through the faucet connection.

4. Rain catchment canopy: Fig.3 shows modified tarp (included in frame set in 2) and fitting installation.

At the center of tarp, cut 2" hole and install SEAFLO Through Hull fitting as rain drainage path. ($8/ea, $28/5ea)

Reference: On Amazon

To protect the tarp's mechanical integrity under strain, 2 plastic round sheets 6" to 8" in diameter (repurposed/cut from used plastic container cover) with 2" center hole. the two plastic round discs are placed on both sides of tarp and held together tightly by the fitting's main nut. Additional 3 small holes are drilled and bolted with locknuts after the Through Hull fitting is installed. An optional screen (for blocking debris) can be added over the 2" fitting opening, such as rain-gutter screen or simple kitchen sink screen by using bolts and locknuts. Please make sure the bulging part of screen is above the fitting, so the debris cannot block water drain path easily. Regular maintenance and cleaning can be done by undoing the bungee cords and lower the tarp to access the center portion of the tarp.

Below the 2" fitting, a PVC extension pipe (2" or more diameter to fit over the fitting and secured by bolt or zip-tie through end of fitting and top of extension pipe.) the length of the extension pipe is determined by the height of frame set (tarp perimeters secured by bungee cords), minus the height of the top opening of IBC tote, then minus the length of the fitting and depth of the tarp funnel (the tarp center will be pulled down by 8" to 12" to establish water down-flow slope, then add about 12" section for allowing downward movement, and finally add about 8" to 12" section inside the tote top opening (this is to ensure the extension pipe stay within tote.)

After securing the tarp perimeters using bungee cords to the top horizontal pipes of the frame, the tarp funnel is established by securing the top of extension pipe (secured to the fitting) to both sides of the tote top opening (there are strong plastic anchor points) using strong zip-ties. Securing both sides provides balance and redundancy of the tarp funnel.

It is noted that this system design allows NO upward tarp movement at the center (even under strong winds or storms), while allowing downward movement at the center (during heavy rain when the water collection is faster than drainage) and the water collected on tarp may increase without destroying the tarp or bending the frame pipes.

the tarp life span may be limited (a few years), but it can be replaced cheaply and easily ($18 for 10' by 10' tarp).

5. Securing the frame set: in addition to anchoring the frame vertical pipes (which is inadequate anyhow under strong wind lifting the tarp), it's necessary to tie the center of horizontal pipes to the IBC tote frame (its weight increases drastically with collected water) using steel cables on at least 2 opposite sides, as shown in Fig.4.

6. Debris prevention: in addition to stainless screen installed over fitting opening (with bulging screen up), addition mosquito screen netting may be wrapped around extension pipe and tote top opening. Please ensure that the extension pipe can move freely up and down without destroying or dragging the screen netting with it. Some debris entering the tote is really not a big issue (see 7 below.)

7. Algae prevention: the easiest way is to drop 1oz or half-oz silver (.999) coin inside each tote. The Ag ions and colloids are effective in controlling algae/bacterial growth in all our totes over 18 months. The traditional technique of wrapping the tote in opaque black plastic sheets requires removing the metal frame and reinstalling the metal frame around the tote after plastic wrapping is cumbersome and may not be totally effective.

Thank you for your kind considerations. Please email enchantedgardens@primeproduce.org with any questions or concerns!

Low Cost, Simple Rain Catchment & Storage System for Irrigation