Stormwater pump installation

Whenever surface or ground water can't leave the property by gravity — the site sits below the council stormwater main, or there's a basement, carpark, sub-floor or low-lying ground that collects water with nowhere to fall to. A pump lifts that water up and out through a rising main. If it can drain away on its own, you don't need one; if it can't, a pump system is the only way the water leaves.

It comes down to what's at risk if a pump stops. For a backyard or garden sump, where an overflow does little more than wet some ground, one properly sized pump is plenty. Garages, basements and any below-ground space are different — if a single pump fails there, water rises into the level you're protecting, and the damage is cars, storage and structure, not a wet lawn. For those we recommend two pumps with a control board so they alternate and either one can carry the site. Our pump systems explained page covers how single and dual systems actually work.

It depends on the head the pump has to push against and the inflow it has to keep up with — including the surge it cops in the first minutes of heavy rain. We size to that duty on site. An undersized pump runs flat-out and never rests; an oversized one short-cycles and wears out fast. We see a lot of oversized units — 1.5kW pumps in basements 3 metres below the street that empty the pit in seconds. Neither extreme is about the cheapest unit on the shelf.

Davey is our default — the most reliable for the money, and it covers most stormwater installs. Where a site wants something more heavy-duty, Grundfos is an excellent option, though it sits at the pricier end. Stormwater keeps the choice simple: it's almost always one of those two, matched to the head and the inflow. We size and pick on the site, not off a shelf, and we'll tell you what's going in and why before we start.

It depends on the state of the system. If the pump still has life in it and it's just been set up poorly — floats hung wrong, valves on the vertical, cabling fouling the floats — we reconfigure what's there. If the pumps are genuinely done, or the wrong size for the basement they're in, we replace them. We make that call on site after a proper look, and tell you honestly which way it falls.

It varies with access to the pit, whether it's a single pump or a dual-pump setup, and whether the existing pipework can be reused or needs reconfiguring. A straight pump swap is shorter than a full reconfiguration in a tight basement sump. We'll give you a clearer estimate once we've seen the site.

Yes — that's all our work, in-house, under our Restricted Electrical (Motors) endorsement. We supply and wire the control board, the isolation switch, the overload protection and the float and alarm wiring. On a dual-pump system the board is what alternates the two pumps, and we recommend a Kenrahn for it. The only part that isn't ours is the property's main power supply to the switchboard — a licensed electrician runs that — and from the board onwards, the whole pump system is set up and connected by us.

That's exactly what sizing is for. We size the pump to the inflow the site actually sees in a downpour, not the trickle it handles on a dry week. Sydney's wetter run of recent years has basements, sub-floor sumps and strata stormwater systems working harder than they were first sized for — which is a big part of why we get called to replace them.

Yes — an independent float set above the pump's normal working range, so if the water ever climbs past where it should, it sounds and lights up while there's still time to call. On strata and commercial sites it can tie back to the building management system. The how-it-works is on pump systems explained.

Yes — basements, carparks and shared stormwater systems across the Sutherland Shire, Eastern Suburbs, Inner West and Lower North Shore, usually as dual-pump systems with a control board. We issue reports formatted for committee minutes and AGMs. Our strata pump services page covers how we work with buildings.