Dewatering pumps empty vaults, pits, trenches, flooded basements, ponds and tanks. Order portable pumps online: the A.Y. McDonald HandyMAC runs from a 12V vehicle battery, the Grundfos Unilift KP and AP12 are stainless drainage pumps to 140 GPM and 52 ft, and the Mini Mac handles small transfers by garden hose. For construction sites, sewer bypass, mines and flood response, Godwin and Flygt dewatering equipment is supplied by quote only. Run the Sump & Sewage Pump Calculator or send us the job for an engineering-led selection. Call 1-888.510.4036 or email sales@watermainsupply.com.
A.Y. McDonald Mini Mac Transfer Pump Kit - 1/6 HP 115V, Garden Hose Connections
Price
From $37.72
Dewatering Pumps
Dewatering Pumps · Portable to Construction-Scale
Dewatering Pumps
Portable pumps that empty vaults, pits, trenches, flooded basements and tanks, ordered online: battery-powered, stainless submersible and transfer pumps from A.Y. McDonald and Grundfos. For construction sites, sewer bypass, mines and flood response, Godwin and Flygt dewatering pumps by quote.
To 140 GPMOnline Pumps
To 52 ftMax Head Online
12V DCBattery-Powered Option
Up to 16,500 GPMGodwin CD by Quote
Quote OnlyGodwin · Flygt
Dewatering means taking water out of somewhere it shouldn’t be: a utility vault, a manhole, a footing trench, a flooded basement, a pond or a tank. The pump depends on the volume, the lift and how dirty the water is, from a 12V pump on a truck battery for a meter pit to a diesel trailer pump moving thousands of gallons a minute out of an excavation.
We sell portable dewatering pumps online from A.Y. McDonald and Grundfos. Godwin and Flygt dewatering equipment is supplied by quote only and is not sold online: send us the job and we come back with the equipment, the reasoning and a price. Call 1-888.510.4036 or email sales@watermainsupply.com. All products are genuine, factory-new equipment in original manufacturer packaging, sold and supported by Watermain Supply, an independent industrial supplier.
Will It Work for Me?
Answered from the manufacturers’ published data.
Warranty
A.Y. McDonald HandyMAC and Mini Mac: 1 year from installation or 2 years from manufacture, whichever comes first. Grundfos Unilift: per each listing. Godwin and Flygt: quoted with the equipment.
Reliability
Stainless steel Grundfos Unilift pumps for sandy water, a HandyMAC with watertight O-ring seals and self-lubricating shaft seals, and a Mini Mac in cast brass and stainless with a replaceable impeller kit.
Fit
Online pumps cover up to 140 GPM and 52 ft of head. Above that, or for diesel drive, trash solids or round-the-clock running, it is Godwin or Flygt by quote.
Size It Now
The calculator sizes surface self-priming and submersible dewatering, checks suction lift and points you to the right family.
Pick the family first; the model follows from flow and head.
Surface self-priming
The pump stays on the ground and draws water up a suction hose. Fast to set and service, but suction lift is limited by atmospheric pressure: Godwin Dri-Prime pumps prime automatically from dry to about 28 ft and can run dry. Godwin CD, HL and NC series; Mini Mac on a small scale.
Submersible
The pump goes into the water, so there is no suction-lift limit and nothing to prime. Right for deep pits, vaults, manholes and confined spaces. Online: HandyMAC and Grundfos Unilift. By quote: Godwin Heidra hydraulic and Sub-Prime electric submersibles, and Flygt drainage pumps.
Specialty
Wellpoint systems lower the water table around an excavation before digging; rotary lobe pumps handle sludge and viscous fluids; diesel backup systems cover lift stations. All engineered to the site, by quote.
Quick rule: if the pump can sit within about 25 ft above the water, surface self-priming is quickest to deploy. Deeper, in a confined space, or with no room at the edge, go submersible.
Order Online
Portable dewatering pumps that ship as listed, no quote needed.
A.Y. McDonald HandyMAC
1/3 HP · 12V DC battery-powered
43 GPMMax flow
25 ftMax head
30 ABattery draw
1-1/2 inNPT discharge
A portable dewatering pump that runs on any 12V truck or car battery, with a 30 ft cable and a waterproof remote controller in the cable. About an hour of running without restarting the engine (times vary).
Watertight O-ring seals
Color-coded battery leads
Repair parts listed separately
Best forUtility crews and contractors pumping vaults and meter pits with no power on site.
Stainless drainage pumps for flooded cellars, groundwater lowering, drainage wells and emptying ponds and tanks. The KP sheds sand; the AP12 has a carrying handle, a clip-on strainer and an automatic float option.
KP: 1/4 to 1/2 HP, 115V, 1-1/4 in NPT
AP12: 1/2 to 1-1/2 HP, 1-1/2 or 2 in NPT
25 ft cords
Best forPortable drainage of clean to gray water, including sandy water.
A small self-priming transfer pump in cast brass and stainless steel for emptying water heaters, bilges, bait tanks, clogged sinks and small dewatering jobs, at 40°F to 130°F. Ships with a spare impeller, puddle scoop and 6 ft suction hose.
Garden hose inlet and outlet
Not for flammable liquids
Impeller repair kit available
Best forSmall transfers and draining flat surfaces with a garden hose.
Sources: A.Y. McDonald Pumps by Baker catalog rev 3/26, pp. 291 and 339–341; Grundfos Unilift data as listed on each product page. A dash means the manufacturer publishes no solids figure.
Verdict: the Grundfos Unilift AP12 moves the most water, to 140 GPM and 52 ft, in stainless steel. The HandyMAC is the only pump here that runs from a vehicle battery. The Mini Mac and the DuraMAC utility pump cover the small jobs with a garden hose.
Godwin and Flygt — By Quote Only
Construction-scale dewatering, sewer bypass, mining and flood response. These are not sold online: we supply them by quote, sized to your site.
Godwin (Xylem)
Dri-Prime CD series: high volume, medium head, large solids; diesel or electric, flows to about 16,500 GPM.
HL series: high-head and jetting pumps with solids handling.
NC series: Dri-Prime with Flygt N-technology non-clog hydraulics for stringy material and sewer bypass.
Wet-Prime: compact engine-driven portable pumps.
Heidra hydraulic and Sub-Prime electric submersibles.
How quoting works: send us the flow or inflow, the lift, the discharge run, the solids and the power available (diesel, electric or none). We return the equipment, the reasoning and a price. Call 1-888.510.4036 or use Request a Quote.
Selection Guide
Job
Typical duty
Start here
How to buy
Meter pit or vault, no power on site
Under about 35 GPM, under 15 ft
HandyMAC 12V
Online
Flooded basement or cellar
Up to about 65 GPM
Grundfos Unilift KP
Online
Drainage well, pond or tank, more flow
Up to 140 GPM, 52 ft
Grundfos Unilift AP12
Online
Water heater, bilge, small tank
A few GPM, garden hose
Mini Mac or DuraMAC 5020PUUP
Online
Construction excavation or trench
Hundreds to thousands of GPM
Godwin CD series
Quote
Sewer bypass, stringy solids
Varies
Godwin NC series
Quote
Long discharge or jetting
High head
Godwin HL series
Quote
Deep pit, mine or tunnel
Beyond suction lift
Godwin Heidra or Flygt drainage submersibles
Quote
Lower the water table before digging
Per system design
Godwin wellpoint system
Quote
Typical duties are guidance. The pump is chosen on its curve at your flow and total head.
Sizing a Dewatering Pump
Flow, total head, and for surface pumps, suction lift.
1. Flow
To empty a known volume, divide gallons by the minutes you can allow (1 cubic foot = 7.48 gallons). Where water keeps coming in, the pump must beat the inflow: measure how fast the level rises with the pump off, and add a margin.
2. Total head
Total head = the lift from the water surface to the highest point of the discharge + friction in the hose or pipe. Long hose runs add up quickly; a size larger hose cuts friction sharply.
3. Suction lift (surface pumps)
A surface pump can only draw water so high: about 25 ft in practice at sea level, less at altitude and with warm water. Beyond that, use a submersible.
Worked example: a 4 ft x 4 ft x 6 ft meter vault, full, with water seeping in at about 5 GPM, on a site with no power. The vault holds 4 × 4 × 6 × 7.48 = 718 gallons. The lift is 8 ft to grade and the hose run is short, so total head is about 10 ft. The HandyMAC makes 34 GPM at 10 ft on its published table, so it empties the vault in about 25 minutes (34 − 5 = 29 GPM net) from a truck battery.
For Godwin and Flygt equipment, we quote purchase; rental is the other route. The duration decides it.
Rental tends to win
One project of a few weeks or months.
Peak demand you won’t see again.
You want the equipment swapped as the job changes.
Buying tends to win
Continuous or repeat use across projects.
Municipal, utility and industrial owners with ongoing dewatering or bypass work.
You want the same equipment ready for every storm season.
Our approach: tell us how long and how often you’ll run it, and we’ll price the purchase so you can compare it honestly with a rental quote.
Why Work With Watermain Supply
Engineering-led sizing
We work out flow, head and suction lift from your site before we quote, and check the pump on its published curve.
Portable to construction-scale
Order the portable pumps online; get Godwin and Flygt equipment by quote from the same people.
Multi-brand honesty
We sell A.Y. McDonald, Grundfos, Godwin and Flygt. If one is not the right fit, we will say so.
Parts and aftermarket
HandyMAC repair parts and the Mini Mac impeller kit listed by part number.
Contractor and utility accounts
Account options for contractors, utilities and municipalities; ask us.
Houston and Gulf Coast
Based in Houston, shipping nationwide, with people who answer the phone, including in storm season.
Frequently Asked Questions
Can I buy Godwin or Flygt pumps online?
No. Godwin and Flygt dewatering equipment is supplied by quote only. Send us the job details and we return the equipment and a price. The A.Y. McDonald and Grundfos pumps on this page can be ordered online.
Which pump runs without power on site?
The HandyMAC runs from any 12V truck or car battery: up to 43 GPM, with about an hour of running before you need to restart the engine. Larger jobs without power use diesel-driven Godwin pumps, by quote.
Surface or submersible?
A surface pump stays at the edge and draws water up a hose, practical to about 25 ft of suction lift. A submersible goes into the water and has no suction limit; use it for deep pits, vaults and confined spaces.
What is the difference between a dewatering pump and a sump pump?
A sump pump is fixed in a basin and switches itself on and off. A dewatering pump is portable and moved from job to job; construction-scale dewatering pumps also handle sand, gravel and trash solids.
Can these pumps handle sandy or dirty water?
The stainless Grundfos Unilift KP is designed to shed sand, and the Unilift pumps pass 0.4 in solids. For heavy sand, gravel and trash, Godwin Dri-Prime pumps handle large solids, by quote.
What is the warranty?
HandyMAC and Mini Mac: 1 year from installation or 2 years from manufacture, whichever comes first. Grundfos Unilift: per each listing. Godwin and Flygt: stated in the quote.
What is wellpoint dewatering?
A ring of small screened wells around an excavation, connected to a vacuum header and pump, that draws the water table down before digging so the sides stay stable. It is engineered to the site and supplied by quote.
Can you help with storm or flood response?
Yes. Call 1-888.510.4036 with the area, depth and power available. We supply portable pumps from this page and quote Godwin equipment for larger volumes.
Ready to Dewater
Order a portable pump online, or send us the job and we come back with Godwin or Flygt equipment and a quote.
Technical data on this page is taken from A.Y. McDonald, Grundfos and Xylem product literature and is subject to change by the manufacturer. Confirm against the current installation manual before specifying. A.Y. McDonald, HandyMAC, Mini Mac, DuraMAC, Grundfos, Unilift, Xylem, Godwin, Dri-Prime, Heidra, Sub-Prime, Flygt and Concertor are trademarks of their respective owners, used here for product identification only. Watermain Supply is a DBA of E4 Industrial LLC, an independent industrial supplier based in Houston, Texas.
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