Rainwater harvesting often gets presented as something that requires a large storage tank and a proper installation budget most households simply don't have. That version exists, and it works well for households that can afford it, but it isn't the only version. A far cheaper setup, built from containers many households already own, can still meaningfully ease pressure during Embakasi East's dry spells.
The basic low-cost setup
At its simplest, rainwater harvesting just needs a clean, covered container positioned to catch runoff from a roof, typically under a downpipe or at a point along a roof edge where water naturally concentrates during rain. A repurposed drum, jerrican, or even several large buckets connected with basic guttering scraps can capture a meaningful volume during a single heavy downpour, Nairobi's rains, when they come, tend to be intense enough that even a modest catchment area fills a drum faster than most people expect.
The container should be covered, or fitted with a simple mesh screen over the opening, to keep out debris and to reduce the risk of mosquitoes breeding in standing water between rains. This is a detail worth taking seriously rather than skipping, an uncovered water store is one of the more common objections we hear from households hesitant to try harvesting, and it's also one of the easiest problems to solve with a scrap of mesh or cloth secured over the opening.
What harvested water is realistically good for
Harvested rainwater from an unfiltered household setup like this is best used for non-drinking purposes: watering compound plants and young trees, cleaning, laundry, and topping up water for general household chores that don't require potable water. It isn't a substitute for treated drinking water without additional filtration and treatment, which is a more involved step most households setting up their first low-cost system don't need to take on immediately.
Even limited to non-drinking uses, the impact on a household's overall water demand is real. Households we've worked with through our sustainability sessions who've set up even a single-drum system report noticeably less reliance on purchased or delivered water for watering their compound plants during dry spells, which is often one of the larger discretionary water costs a household carries.
Sizing and placement for a typical Donholm compound
Most Donholm compounds have enough roof area to make even a single 200-litre drum fill several times over a single rainy season, especially if positioned under the largest unobstructed roof section rather than a smaller outbuilding roof. Positioning near where the water will actually be used, close to a kitchen garden or the compound's young trees, saves the effort of carrying full containers any real distance afterward, a small detail that makes a real difference in whether a household keeps using the system consistently once the novelty wears off.
Households with more roof area or wanting greater capacity can connect multiple containers with basic overflow piping, so that once the first fills, excess water diverts to a second rather than simply overflowing and being lost. This is a natural next step once a household has tested the basic single-container setup and found it useful enough to expand.
How we support households getting started
We cover rainwater harvesting as part of our broader water conservation sessions, alongside greywater reuse and leak repair, with a hands-on demonstration of a basic single-drum setup using materials most households can source cheaply or already have on hand. It pairs naturally with the mulching and composting habits we teach elsewhere, all three reduce a household's dependence on inconsistent water supply during the dry months.
If your household is interested in setting up a low-cost system before the next rainy season, our next water conservation session is listed on our Get Involved page, and our team is happy to advise on positioning for your specific compound if you reach out through our Contact page beforehand.
Maintaining the system once it's set up
A low-cost system still needs some basic upkeep to stay useful. The mesh or cloth covering the opening should be checked periodically and replaced if it tears, since a damaged cover defeats the purpose of keeping debris and mosquitoes out. The container itself benefits from an occasional clean, particularly at the start of a new rainy season after sitting empty or partially full for a while, to clear out any sediment or debris that's settled at the bottom.
Households using harvested water for a kitchen garden or young trees should also check periodically for any unusual smell or discolouration, a sign the stored water has sat too long without turnover or that something has gotten into the container despite the cover. In our experience, households that build a simple habit of a quick visual check whenever they draw water from the container rarely run into problems, it's a small addition to an already-established routine rather than a separate maintenance task to remember.