Two things about Nairobi change how a pump package should be specified, and neither appears on a manufacturer's data sheet. Much of the city is built on black cotton soil, which holds water rather than draining it, so excavations fill from rainfall and runoff rather than from steady seepage. And at about 1,795 m above sea level, a naturally aspirated diesel engine delivers noticeably less than its rated output. A package selected on sea-level engine curves for free-draining ground will underperform here, and it will do so in ways that look like a fault rather than a specification error.
Space at the edge of a Nairobi excavation is usually contested, and lowering a unit into an active dig is impractical on a tight urban plot and sometimes unsafe. Every eBORA model self-primes to 8.5 m, so the pump can be sited clear of the works and still draw from the sump, and it re-primes on its own when the suction line drains rather than needing someone on site to restart it.
Nairobi's expansive clays have low permeability, so excavations here fill mainly from rainfall and surface runoff rather than from fast groundwater ingress through the walls. That changes the duty: flow is event-driven and peaky rather than steady, and the water arrives carrying suspended fines that are abrasive without being large. Sizing for a constant seepage rate tends to produce a pump that is oversized between storms and undersized during them.
The long rains run roughly March to May and the short rains October to December. Dewatering demand follows them, which means a pump spends much of the year idle and then has to start unattended when a storm fills a sump at night. Automatic re-priming matters more than peak efficiency in this pattern: every eBORA model re-primes on its own when the suction line drains, so it restarts without anyone on site.
A naturally aspirated diesel loses roughly 3% of its rated output per 300 m of elevation, which puts a Nairobi site somewhere near a 15 to 18% derate against the sea-level figure. Turbocharged engines lose less. This is engine behaviour rather than pump behaviour, but it decides whether the package actually delivers its duty point, so confirm the derate against the engine manufacturer's own altitude curve before committing to a diesel selection. Where a grid connection exists, electric drive sidesteps the problem entirely.
State the site altitude when you ask for a quotation if the package is diesel driven. Engine output falls with elevation, and a set specified against sea-level curves will not deliver its rated duty here.
Calculate total head rather than vertical lift alone. Friction loss along a long discharge run frequently exceeds the static lift, and this is independent of altitude.
Where the water carries suspended clay rather than granular debris, solids-handling size matters less than wear resistance — the fines are abrasive at every particle size.
Where a site has no grid connection yet, compare a derated diesel package against the cost of a temporary supply before defaulting to diesel.
Where the city's pumping demand actually comes from, and the technical detail behind each.
Deep basements in Upper Hill and Westlands, and the excavation work that comes with a dense high-rise corridor, are the city's most common dewatering duty.
Construction pumpingUrban stormwater, sewer bypass and drainage works along the Nairobi and Ngong river corridors, where flood response is seasonal and time-critical.
Infrastructure pumpingHorticulture within reach of the city, including the Athi basin and the Naivasha corridor, where abstraction distance and line pressure set the duty.
Irrigation pumpingIt affects the engine rather than the pump. A naturally aspirated diesel loses roughly 3% of its rated power per 300 m of elevation, which puts a Nairobi site near a 15 to 18% derate against the sea-level figure; turbocharged engines lose less. Allow for it when the package is diesel driven, and confirm the figure against the engine manufacturer's own altitude curve. Electric drive is unaffected.
It makes the inflow event-driven rather than steady. The clay's low permeability means an excavation fills mainly from rainfall and surface runoff instead of groundwater moving through the walls, so demand spikes during a storm and falls away between them. It also puts suspended fines in the water, which are abrasive at every particle size, so wear resistance matters as much as solids-handling capacity.
The B Series is the usual starting point, spanning 245 to 3,350 m³/hr with solids handling from 44 mm to 124 mm. Where an excavation is deep or the discharge point is distant, the L Series reaches 295 m of total head while still passing solids from 19 to 64 mm. The right answer depends on the duty point, so send the flow, the total head and the site altitude.
Yes. Nairobi is the operating base, and we supply across Kenya and the wider East African region from here. The conditions described on this page are specific to Nairobi; a site at the coast or in the Rift Valley has a different altitude and different ground, and both change the specification.