Every Drop Of Water Counts
Making the most of the rains
At Thousand Herbs and Vegetable Garden, Manyangana High School, we have helped to implemented water management measures to optimally use all rain water that falls on the property, to ultimately assist the vegetable garden in producing as much food as possible.
The first step was to install gutters and 4x 5000l JoJo tanks to collect and store any run-off from the school's roof when it does eventually rain.
Next, to make the best use of any future run-off water entering the property from uphill as well as to reduce erosion, swales were constructed to help manage this. Swales are really just a shallow ditch running across the landscape, dug on contour in appropriate intervals, depending on the slope of the land and the size of growing area, with rows of vegetable beds prepared in-between. The swales have a raised, mounded edge on the downhill side. These mounds are then planted with hardy beneficial perennials to help hold the shape in place. Berms are then built at the ends of the swales to help direct any water flow into the ditch.
In the event of heavy rainfall, a swale in conjunction with its berms helps to direct and collect runoff water, thus allowing it to soak into the land. The idea is to slow down the water, reducing the risk of erosion, and to keep as much of it as possible from leaving the property, creating a form of subterranean irrigation. On a larger scale these can also be used to help direct water towards dams and can greatly assist in increasing the water table.
Similarly, we have dug two pits with mounded edges near areas of the garden where runoff from the school buildings collect and has previously caused some bad erosion. Pawpaw and banana trees will be planted on these raised edges and these should benefit from a more moist and humid micro-climate that these pits will help to create.
Now all we need is rain, and with most of the neighbouring provinces receiving heavy downpours at present – things are looking good!