I thought I'd take the opportunity with a recent storm, to explore how we're dealing with water run-off. Normally it would all just run down the slope as quickly as possible, until it reaches flat ground at our lowest gully. This creates soil erosion however, so over the many, many, many years, we've been digging a series of swales to direct how the water flows.
Click all images to enlarge
Forgive the weeds. Its autumn and we're slowly removing them and mulching the swales and plants with them. A season of natural equity goes back into the soil.
We have one swale on the top slope, directly above the house, which redirects water that comes from the street and our neighbours' driveway (above). But there's also a middle swale, which wraps around the immediate vicinity of the house. Any water which collects, gets moved slowly north. These middle swales, always fill relatively quickly and seem to drain within 24 hours.
Same middle swale
House, left, cross the swale to reach both chicken coops, right
We've built these over several growing seasons, and even used them as dumping grounds for prunings. As they break down, they fill any ruts we have in the soil, but also act as filters for the water which passes through. It's been wonderful at recycling our natural materials, with the bonus of slowing the flow.
As much as we try to capture and retain the water on level swales (dug on contour) it inevitably has to travel down a small slope, because, well, we live on slopes and that's the way gravity works.
From here, the water would normally launch on the north facing ski-ramp, and chew its way down the slope. But not since we've dug our newest swales. It's a slow process digging by hand, but the job inevitably gets done. Swale 1 is in the middle of construction, and swale 2 is yet to be started.
This picture doesn't really illustrate how long the swales are going to be, but shows the path the water is going to take nonetheless. Its going to travel twice down the slope, with strategic spillways in the swales, to move the water further down hill as they fill.
We already have a semi-mature mulberry tree to help take up some of that moisture and nutrient flow, but we also have a mango tree in the distance, out of shot. More on that in another post.
But now this is where it gets interesting...
Where does all this water lead, you may ask? Straight to the flattest ground, which happens to cut through the middle of our property. This is where all the water events, end up merging together. We get water from our own property meeting with water entering from our neighbours lands, which all deal with the water coming off the street above.
Its a network we're hoping to tap by slowing the flow - especially the velocity where the water enters from our neighbours land. They've built a concrete culvert to cross the gully to their house. The water sheds from the bitumen road quickly, enters several properties with no means to slow the flow, then it shoots like a bottleneck, through our neighbours concrete culvert.
The speed in which it enters is so forceful, it cuts a new path nearly every time. It digs deeper and deeper into the soil, creating chasms at least a metre deep on our neighbours side. Our only hope to stop that kind of erosion happening on our land, was to choke it out with natural materials - in this case, grass, weeds and what-have-you. We're somewhat chuffed you cannot see the enormous erosion channel that used to be here. Its been choked out with thriving grasses growing on old debris instead.
We had to slow the flow by using a similar strategy to the middle swale - by dumping old prunings and such into the channel. Not in all of it, mind you, just at strategic points so the water could spill over if there was too much. We don't burn our debris (not until we get a wood heater) but we tend to drown them instead. Aren't we lovely.
Mulberry tree #2
water flows to the left (mostly) but can also spill over to the right
A little further down stream, is a somewhat younger tree to our first mulberry, and its planted here to take advantage of the water and nutrient flow. We thought the first mulberry grew fast, but this one is on steroids. Its about half the age of our original tree but growing twice as fast.
What I have just shown you in these series of photos, has been many years in the making. We are still doing a lot of work, but nature is helping us too. With each monsoon season that passes through, more elemental forces help to shape our lower gully. We have a lot of gullies on our property, this just happens to be the biggest and with the most potential to tap, as land stewards.
There is so much work to do here, and God willing, we will finish it. The work is pretty simple though - dig, prune, dump and see what the monsoon season leaves behind.