Imagine having this much water. And knowing you made it happen. The Cascata Delle Marmore Falls in Italy are manmade, built to solve problems of another manmade water flow. Moving water is a long held skill of humans, though the Romans were immensly expert in moving large amounts long distances.
For the arid American West, water doesn’t come so easily to cities in the Rockies’ rainshadow. We are witnessing year over year water level declines in natural waterways. While I cannot solve the problems with the Colorado River watersheds, I do have influence on land along the front range. To make the most of what water we get, I am reading the book, “Rainwater Harvesting” by Brad Lancaster and wow. This IS it. This is what I want to be doing. This combines the knowledge from both my Geology degree and my twenty year passion for gardening.
The land I will learn on this year is a very sandy site. It’s an old farm that’s lost many of its shade trees to disease a dozen years ago. That combined with recent drought, and weed mitigation, it’s hillsides are bare. There are little nutrients and sparse vegetation. The goal is to stabilize the soil with a new seeding of grasses. As we learn the habits of the runoff from buildings, the hope is to provide drainage to this area without changing the water a large cottonwood tree receives.
And where better to start than a hillside that looks like this? I will be working with the concept of a “berm and basin” earthwork. Earthworks are forms created by moving an area’s dirt and rock to change the elevation of land and direct the flow of water. In the case of a berm and basin, berms are built up on the downhill side using the materials dug out in forming a basin towards the uphill side. The space between berms is 4 times the width of the basin. At each berm there are places for overflow that allows water in the upper berms to flow down to the next berm.
The next time you do dishes, try this experiment. On the side you use to rinse, stack the dirty dishes from largest at the bottom to smallest. Alternate bowls and plates, so that water can run into and over them. As you rinse, notice how you fill up each consecutive bowl or plate. This is what we intend to do in the landscape.
Start at the top and work your way down
Gathering water at the highest point gives you the ability to guide it movement and pace.
By slowing it down, plants are better able to get a drink before it evaporates or runs away. At the homestead we are starting at the top of the western edge of the property. The house forms the highest point and its drainage from 4 downpipes will represent the source.
We will be creating some berms using concrete block to feed western facing trees on a desicated western slope. On the southern most tree that berm will extend 270 degrees. These berms will be fed by different downspouts. Further down they may be tied together by an overflow earthen basin following the natural contour.
As you move from the house to the field earthwork berms will take their place. Here is a link to a beautifully done boomerang berm a Peace Corps Volunteer helped build in Senegal in 2013. To read more: See rainwater harvesting section
When I’m done with ours I will post it up. I was also inspiried by landscape architect students in Tuscon AZ. The project focused on a school without shaded areas and outdoor greenscape. Using water harvesting techniques as a basis for the planted areas, trees will grow at their best. Their project went beyond concept to physical form. Not only does it help the trade it shares valuable knowledge with a communities’ children. The design: High school campus retrofit
Ancient Berm/Basin created oases
In southeastern Utah you can find examples of areas where water has been gathered and creates lush vegetation where normally you would not find it. These plants are peach leaved willows. A sign of year round water.
At night you can hear the frogs enjoying these man enhanced pools.
This narrow canyon faces north east and is undercut at its base. The water runs out from a spring and is pooled under the over hang. In this part of the desert, water rarely runs all year.
In Greece the bouganvilla and grapes or fig?? seem to grow from concrete. But in reality there is a basin that water flows into to keep this alive. If only I knew when taking these photos there would have been a close up of the tree well.
In arid regions water is precious. As long as 12,000 years ago water was captured for use in waterproof recepticles. An old technique uses lime plaster as a lining to hold in the water. To prevent evaporation many cities employed underground cisterns. This gorgeous one in Morocco was created by the Portugeuse.
In the late 1800’s London had the most wonderful cisterns hidden from view but ART all the same. Their purpose was to hold fresh water for use in the crowded city.