Protecting our water resources is a vital part of living on a smallholding. Whether this is a natural water course such as a river or stream, or your borehole, or simply rainwater runoff, smallholders must do what we can to reduce runoff to a minimum and to prevent our activities from causing contaminated runoff into our water sources. By nature of living on a smallholding, it is likely we are producing agri-chemical runoff (fertilizers and pesticides), waste water contaminated with cleaning products (such as used to clean a chicken house), grey water, and black water (sewage).
The first step to preventing runoff is to manage your use of chemicals ~ particularly after you’ve used them. In certain cases, such as the cleaning of equipment in a dairy or chicken house, for example, it is possible to put the used chemical-filled water in containers to prevent it soaking into your water systems. To do this, wash your equipment in a sink or basin that allows you to scoop most of the water out when you are finished.
Or if it is the entire dairy, stable or chicken house that has to be cleaned, change the disinfectant system to one that minimises the need for extensive use of rinsing water. An option in this regard is the Sagewash spray system highlighted in the Smallholder, September 2022.
Even so, due to the concentration of chemical pollution in some agriculture waste water, some experts suggest one tries to diffuse the pollution. This means creating ways to slow down your water runoff and spread your water around, preventing high concentrations of polluted water from entering a water source all at once, or at all. Some ways to diffuse your water pollution include:
- Planting cover crops to act as a buffer for your water. These crops slow down the movement of your water ~ often containing fertilizer or pesticides ~ allowing more to soak into the ground, rather than allowing flow at full concentration into a water source.
- Plant indigenous trees and shrubs close to your waste water source. This will help in filtering water before it enters your watercourse.
- Keep livestock away from open water sources. This prevents faecal contamination.
- Build holding walls (properly named berms) around your manure and compost piles. This will prevent any raw manure or excess rainwater runoff from falling into any open water source.
- Build your manure piles away from your borehole. This prevents contaminants from raw manure seeping into your borehole water.
In crop farming, unless you are farming organically, your polluted runoff will contain mostly chemical fertilizers and pesticides. Before preventing runoff, you can better manage your crop production to prevent the use of these at all ~ or at least reduce use.
First, intercropping and companion planting using pest-repellent plants will reduce the need for pesticides. Marigolds, for example, are said to help keep certain bugs and pests away. Intercropping in general also encourages biodiversity, which will draw natural pest predators to your crops, again reducing the need for chemical pest repellents.
No-till or conservation tilling increases your ground cover, which slows down water and encourages it to soak into the soil before it runs off.
On gently sloping ground a simple contouring practice borrowed from the permaculture movement will greatly reduce water runoff and thus improve your own soil and water use. That’s the practice of building swales – shallow, shaped ditches along contour lines in the field. This is done by removing soil along the contour and piling it to downhill of the resulting shallow ditch. The whole thing, ie ditch and soil pile, is then smoothed and resown with pasture seed. The result, called a swale, should not be deep, but rather a slight slope that still allows, for example, a wheeled vehicle such as a tractor or quad bike to work in the field with ease.
Like the contours of a ploughed field you can make as many swales as you wish, the choice being dependent on the size of your field, the amount of rain you receive, soil type, and your appetite for hard work.
Any rainwater runoff collects in the ditch – or ditches – rather than running down the hill and out of the bottom of the field. In a few years’ time a good mini-biome will have developed in the ditch and you can then plant it with saplings of trees or forage crops such as tree lucerne.
On plots with stables or chicken houses that require regular cleaning, planting indigenous shrubs and grasses along your waterways will help diffuse pollution. But, you must take care not to overcrowd your drainage and gutter areas which will prevent any drainage and can cause flooding, and stagnant water pooling. Trees strategically planted around your chicken house, near your fans, will help both to slow your water runoff and disperse and absorb air pollution as well.
Don’t keep your livestock uphill from water, whether this is a natural water course or your borehole. Make sure your livestock are downhill, which will prevent manure runoff from entering your water.
Manage your manure. Nutrient-rich manure makes very good compost and fertilizer, but when used in excess the nutrients it contains can seep into groundwater and waterways, polluting water and encouraging algal blooms that starve the water of oxygen.
If you are farming for subsistence and hobby reasons, it is likely that the amount of manure your plot produces can be stored, composted and used on your crops. However if you have larger herds or flocks, you will need to implement adequate manure management. This means storing your manure to prevent it entering waterways and seeping into the ground. You can set up a small compost business, or give it to neighbours who perhaps don’t have livestock ~ they can use it on their crops and in their gardens.