A dewatering pump removes accumulated water from construction sites, mines, tunnels, and industrial areas. The two main types are submersible dewatering pumps (CDW series, immersed directly in the water source) and auto-prime surface pumps (CAP series, up to 1,550+ HP for high-volume flood and mine duty). Cosmos Pumps manufactures both, from 1.5 HP to 1,550+ HP, across 6 product series.
Pump selection comes down to four variables: available head, HP requirement, solids content in the water, and whether the application needs a fixed installation or portable deployment.
| Model | Type | HP Range | Max Head | Flow Rate | Best For |
|---|---|---|---|---|---|
| CDW Standard | Submersible dewatering | 1.5–50 HP | 86.5 M | 450–8,500 LPM | Construction pits, tunnels, basements, highway drainage |
| CDW High Head | Submersible dewatering, high head | 5–75 HP | 140 M | 350–2,200 LPM | Deep mines, hydro power construction, long-distance tunnels |
| CDW Ultra High Head | Submersible dewatering, ultra high head | 50–120 HP | 200 M | 50–200 m³/h | Underground hard rock mines, metro shafts, deep infrastructure |
| CNC Non-Clog | Submersible vortex, non-clog | 6–20 HP | 30 M | 1,250–1,500 LPM | Sewage bypass, manhole cleaning, mixed-waste construction sumps |
| CSW Sewage | Submersible sewage | 2–200 HP | 60 M | 775–33,000 LPM | Municipal STP, sewage lift stations, industrial ETP |
| CAP Auto-Prime | Surface diesel or electric | Up to 1,550+ HP | 169 M | Up to 74,483 LPM | Flood control, open-pit mining, large civil infrastructure |
For slurry applications (coal runoff, ash transfer, harbour construction, thermal power stations), see the CSL Slurry Pump series.
Five site conditions determine the correct selection:
| Site Condition | Key Question | Recommended Model |
|---|---|---|
| Installation type | Can the pump be submerged, or must it sit on the surface? | Submerged: CDW series / Surface: CAP series |
| HP required | What flow rate and head does the site demand? | 1.5–50 HP: CDW Standard / 5–75 HP: CDW High Head / 50–120 HP: CDW Ultra High Head / 60–1,550+ HP: CAP |
| Solids in water | Clean or muddy water, or large solids? | Up to 12 mm: CDW / Up to 70 mm: CNC Non-Clog / Sewage and sludge: CSW |
| Power source | Is reliable electrical supply available on site? | Electricity: CDW submersible / No or intermittent power: CAP diesel |
| Portability | Does the pump need to move between multiple sumps? | Single fixed sump: CDW submersible / Multi-sump or mobile: CAP on trolley |
For most construction and tunnel dewatering below 120 HP with mains power, the CDW submersible range is the standard choice. For mine flood control, large open-pit volumes, or sites without reliable power, the CAP auto-prime diesel range is the engineering answer.
Selecting the wrong HP is the most common site error. This table maps typical applications to the correct bracket.
1.5 HP: Basement sump pumps, small trench drainage, residential foundation pits. CDW Standard 1.5 HP handles up to 450 LPM at low head.
3–5 HP: Medium construction site sumps, road dewatering, small irrigation channels. CDW Standard 5 HP handles 2,500+ LPM at construction heads up to 40 M.
10–20 HP: Large foundation pits, factory basements, monsoon drainage. CDW Standard 20 HP; or CDW High Head 10–20 HP where heads exceed 40 M.
50 HP: Deep foundation excavations, highway tunnels, mine access drives. CDW Standard 50 HP or CDW High Head 30–50 HP for heads above 80 M.
75 HP: Active mine dewatering below 100 M, hydro power plant construction. CDW High Head 75 HP handles 2,200 LPM at 140 M shut-off head.
50–120 HP (ultra high head): Underground hard rock mines, deep railway tunnels, metro shafts in rock. CDW Ultra High Head handles up to 200 M shut-off head with a 2-stage SS316 impeller and dual SiC mechanical seals.
Above 100 HP, surface deployment: Mine flood control, river diversion, municipal flood duty. CAP diesel auto-prime pumps from 60 HP to 1,550+ HP. The full fleet is available for dewatering pump rental across India and overseas.
For HP-specific pricing, see the Dewatering Pump Price Guide.
Active dewatering is required by law on any excavation below the natural water table. The CDW Standard series (1.5–50 HP) covers the full depth range, from basement pits (3–5 HP) to highway tunnel drives (CDW High Head 20–75 HP). Cosmos Pumps deploys 300+ submersible units annually across building, metro, and highway construction.
Mine dewatering in India operates under DGMS (Directorate General of Mines Safety) guidelines. Open-pit coal mines use CDW Ultra High Head (50–120 HP) for pit depths to 200 M; CSL slurry pumps handle coal runoff sumps separately. Underground hard rock mines need CDW High Head or Ultra High Head for continuous-duty high-head operation. Cosmos runs 50+ mine dewatering projects per year.
For a detailed mine pump selection guide, see the Mine Dewatering Guide.
Flood dewatering needs high flow rate sustained over hours. The CAP auto-prime diesel surface range (60–1,550+ HP) handles flood control with self-priming up to 9.8 M suction head and run-dry tolerance built into the design. Cosmos deploys 80+ CAP pumps annually for municipal and infrastructure flood duty.
Metro and railway tunnels need continuous high-head dewatering with minimal maintenance access. Both CDW High Head (5–75 HP, up to 140 M) and CDW Ultra High Head (50–120 HP, up to 200 M) carry Class H insulation (180°C) and dual TC vs TC mechanical seals rated for continuous immersed operation.
Municipal sewage bypass, STP construction, and ETP commissioning need pumps that pass large solids without clogging. The CNC Non-Clog (6–20 HP, up to 70 mm solids via bottom discharge) is built for construction sewage bypass and manhole cleaning. The CSW sewage series (2–200 HP) covers permanent municipal STP and sewage lift station installation.
For the dedicated sewage pump page, see Sewage Pump (CSW Series).
Rental is the right call when:
Purchase is the right call when:
Cosmos Pumps runs a rental fleet of 50+ Auto-Prime pumps (60–105 HP) and 500+ submersible dewatering pumps (3–75 HP), available across India and overseas. For project-specific rental queries, see Dewatering Pump Rental.
Cosmos Pumps Pvt. Ltd. manufactures dewatering pumps from its 25,000 sq. ft. Faridabad NCR facility: 1.5 HP to 1,550+ HP across 6 series, designed for Indian site conditions. The company holds 6 certifications: ISO 9001:2015, CE Marking, ZED Gold (Ministry of MSME), NSIC, UL Compliance, and EAC (Eurasian Conformity). It exports to 20+ countries.
2,500+ customers served across 5,000+ completed projects and installations worldwide.
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A dewatering pump removes water accumulated in a confined area: a construction pit, mine sump, tunnel, or flooded industrial site. Unlike a domestic sump pump, industrial dewatering pumps handle suspended solids, operate continuously while immersed, and are built for site environments with Class H insulation (180°C), dual mechanical seals, and SS-410 nitride-hardened impellers. Cosmos Pumps manufactures submersible dewatering pumps from 1.5 HP to 120 HP and diesel auto-prime surface pumps up to 1,550+ HP.
Construction site HP depends on pit depth and inflow rate. For standard foundation and basement pits to 8 M depth with moderate inflow, a CDW 3–5 HP handles 1,500–2,500 LPM. Highway tunnel drives or metro shafts to 50 M typically need CDW High Head 20–30 HP. Deep tunnel construction from 50–100 M requires CDW Ultra High Head 50–120 HP. For sites without reliable power, the CAP diesel auto-prime provides equivalent HP performance without needing mains supply.
A dewatering pump handles clean or muddy water with solids up to 12 mm: groundwater, rainfall runoff, flood water. A sewage pump handles raw sewage with solids up to 100 mm (CSW series) or thick mixed waste to 70 mm (CNC Non-Clog). The materials differ: dewatering pumps use SS-410 impellers for grit abrasion resistance; sewage pumps use SS or CI impellers with larger solids clearance. Cosmos Pumps manufactures both product lines, available for purchase or rental.
Dewatering pump prices in India range from approximately Rs 8,000–Rs 25,000 for CDW 1.5–3 HP submersible models, to Rs 80,000–Rs 2.5 lakh for CDW High Head 20–50 HP units, to Rs 10 lakh–Rs 50 lakh+ for CAP diesel auto-prime pumps above 100 HP. Price depends on HP rating, shut-off head, material of construction, and engine specification. For the complete breakdown by HP tier, see the Dewatering Pump Price Guide.
A standard CDW submersible dewatering pump should not run dry: motor cooling depends on surrounding water. The CAP auto-prime surface pump handles dry starts by design, since the auto-priming mechanism primes the pump from a dry state automatically. For sites where sumps empty between inflow events, the CAP diesel is the correct choice. Cosmos CDW submersibles with Class H insulation carry thermal sensors that cut power before damage occurs on incidental dry-run.
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