Rain Harvesting in Zimbabwe

The summer rains have arrived in Zimbabwe, bringing much-needed precipitation after the long dry season. For homeowners with gardens and small farms, the rains present an opportunity to harvest and store water for use during the rest of the year. With a few simple practices, Zimbabweans can capture and utilise rainwater in environmentally sustainable ways. Here are some tips for water harvesting and efficient use this wet season.

Evaluate and Prepare Your Catchment Area

The size and materials of your roof determine how much rainwater you can collect. Larger, non-absorbent metal or tile roofs are ideal. If you have the space, also consider diverting water from non-roof surfaces like driveways into your water harvesting system. Install gutters and pipes. Gutters collect rainwater runoff from your roof and transport it via downspouts into storage containers. Make sure gutters are clear of debris before the rains start. Check joints for leaks and secure loose sections. Wide half-round gutter profiles capture more rainwater than narrow profiles.

Acquire Water Storage

You have many options for rainwater storage tanks, including above-ground plastic tanks, concrete tanks buried underground, and converted used tanks like old shipping containers. Choose a size and material suitable for your budget and space. Place your tank on a stable, level platform near your home for easy access.

Capture Rainwater In Situ for Garden Beds 

Create swales and berms to hold water in your garden. Swales are shallow trenches dug along the contour of your land to collect water runoff. Berms are mounded barriers that help retain water in swales. Line swales with permeable materials like rocks or mulch. Swales water your garden beds slowly from below, reducing evaporation. Apply 5-10 cm of organic mulch like wood chips or straw around your plants. This protects soil from hard rains, prevents erosion, and reduces water loss from evaporation. Mulching also suppresses weeds and enriches your soil as it breaks down.

Efficient Irrigation Techniques

 Consider drip irrigation for efficient watering. Drip systems deliver water directly to plant roots through networks of tubes and emitters. This conserves water compared to sprinklers and hoses, which lose ample water to evaporation and overspray. You can gravity-feed drip lines from your raised water tank. Water early, deeply, and less frequently. Most plants do better with one long soak per week rather than shallow daily sprinkling, which encourages weak shallow roots. Water early in the morning to reduce evaporation. Check soil moisture before watering again - don't stick to a fixed schedule.

Sustainable Landscaping

 Grow native and drought-resistant plants. Native Zimbabwean plants are adapted to local soils and rainfall patterns. Drought-resistant exotic plants like succulents and cacti also thrive with minimal watering. Focus rainfall capture on your veggie patches and ornamental beds - your hardy natives can fend for themselves.

Greywater Reuse 

 Repurpose household greywater. Reusing the relatively clean wastewater from sinks, showers, and washing machines reduces environmental impact. Direct greywater onto ornamental plants and fruit trees - avoid edible crops eaten raw. Don't store greywater more than 24 hours to prevent harboring microorganisms.

Maintenance of Your Water Harvesting System

 Inspect gutters, pipes, and tanks periodically. Make repairs to prevent precious wet season rains from going to waste. Sediment will accumulate in tanks over time - periodically empty and clean them. Consider installing a first flush diverter to bypass the first wave of dirty roof runoff.

Conclusion

With a few simple practices, Zimbabwean homeowners can maximize water security this rainy season. Harvesting rain in environmentally sustainable ways reduces pressure on municipal supplies and saves money on water bills. Implementing these tips also nurtures a little oasis of green in your backyard! How will you utilize the free rains this wet season