Common Drainage Problems in Nairobi Homes (and How to Prevent Them)

Kitchen drains block because cooking fat and oil are poured down the sink and solidify inside the pipe, building up layer by layer until the bore is nearly closed. Bathroom drains block with hair and soap scum; toilets with wet wipes, sanitary products and — surprisingly often — children's toys. None of these belong in a drain. Fat goes in a container and the bin once cooled; wipes are advertised as flushable but are not; a simple hair catcher in the shower tray costs almost nothing and prevents most bathroom call-outs.

Some drainage problems are built in, not caused. A drain run laid without enough fall lets wastewater crawl instead of flow, so solids settle and the line slowly silts up; a run with too much fall drains the water away and leaves the solids behind, with the same result. Misaligned or poorly solvent-welded joints catch debris and snag paper. If a drain blocks repeatedly in the same spot, the cause is usually in the pipe itself — a re-graded run or a properly installed access point fixes the pattern instead of paying for endless unblocking.

During the long rains, surface water overwhelms anything that was underestimated: gutters discharging beside the foundation instead of into a safe outlet, yard drains sized for a light shower, and soak-pits sitting in saturated ground. Before the rains arrive is the time to clear gutters and downpipes, check that water is carried well away from the building, and have slow drains flushed rather than waiting for the first storm to test them.

Mature trees and landscaped gardens are a quietly common cause of recurring sewer blockages: fine roots find the smallest joint gap, grow into a mat that catches paper and solids, and grow back after every mechanical clearance. If a line blocks on a seasonal rhythm, or clearing always pulls back root strands, the permanent fixes are root cutting with the right cutters, sealing or relining the joint, or rerouting the line away from the tree.

Once or twice a year: flush drains with hot water and check flow rates at every outlet; clear gutters before and after the rains; confirm manholes and inspection covers are accessible and not buried under paving or planting; and have any drain that has blocked twice in a year camera-inspected or at least properly rodded rather than repeatedly plunged. For wastewater treatment, a bio-digester that is correctly sized and installed needs far less attention than a neglected septic tank — and never suffers the desludging emergencies an overloaded tank produces.