"...they're not growing their own food. Like the 55 gallon rain barrel, they deceive themselves by thinking that by toying with inadequately designed rainwater collection systems...
Thirty five thousand gallons of rain falls off my roof but I want to hold fast to the cute idea that a little 55 gallon barrel will hold it all and I can feel like I've saved the world. That’s simply poor design and living through your concepts rather than your observations."
While not all of us can have a 100+ acre Permaculture farm that utilizes the landscape to harvest rain water, we can gain some insight from Mark's comments. When you consider the amount of rain we typically get in central Iowa and the surface area of our roofs, you realize that we cannot hope to contain it all in one, or even several, 55 or 75 gallon rain barrels (see calculator). Ideally you would have several modified 275gal. Intermediate Bulk Containers (IBCs) which can be an eyesore if not properly disguised and take up a large footprint.
What we can do to bridge the gap in our urban/suburban rain water harvesting systems is to utilize the rain barrel as storage for use in our potted plants, etc. that we want to benefit from using rain water over the municipal water supply. More importantly, though, we want to manage the overflow so we can use the rain to maintain soil moisture for longer periods of time.
There are several ways we can Divert, Disperse & Conserve the overflow to our planting areas:
- This picture below is of my prototype rain catchment system. It utilizes a smaller barrel and simple overflow into 4" drainage tile (8' solid to get away from the foundation, then 16' perforated to allow the overflow to slowly drain into our mini-forest garden.
- This next system utilizes a more intricate overflow irrigation system. The overflow drained into a series of PVC pipes that were set-up with multiple junctions, runs and 1/4" drainage holes that allowed the overflow to go to targeted areas of the planting. The tricky part was running a split under the walking path and back up into the "island". Make sure your system completely drains all water so the lines will not freeze and burst in winter.
|Before hiding the barrel behind a trellis|
|Dividing the overflow to multiple areas|
|The lower levels prior to covering PVC with straw|
- Another way to enhance water retention is through mulching. Mulching keeps direct sunlight from heating and drying the soil. It also holds a layer of moist air that won't blow away in drying breezes and steal moisture away.
- "Swales on Contour" will also slow runoff and allow it to sink into the soil. Typically swales in modern construction flow with the slope of the land to route rainfall quickly to drainage ditches, rivers and streams. Two days after a rain suburban homeowners are out with the sprinklers trying to keep the grass green. With swales on contour, the "ditch" runs across the slope where the runoff slows, giving it time to percolate into the soil.
Thanks for stopping by and reading my blog,