Stormwater well

A stormwater well is a chamber used to collect, drain, and sometimes pre-treat rainwater (stormwater) from ground surfaces, roofs, roads, and paved areas.

It is a central part of the stormwater system in both private properties and municipal water and sewer networks.

A stormwater well is installed in the ground and receives rainwater, drainage water, or meltwater from:

• street inlets
• ground grates
• downpipes
• drainage pipes
• surface runoff from yards and driveways

The well directs the water further to:

• a stormwater pipe
• infiltration
• a soakaway (rock pit)
• a detention or storage chamber
• a pond
• an open ditch

Stormwater wells are therefore used to prevent flooding, protect buildings, and control where water flows.

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How Is a Stormwater Well Constructed?

A typical stormwater well consists of:

Well chamber

– plastic (PP/PE) or concrete

Grate or cover

– allows surface water in, often in load class B125 or C250

Sediment trap (silt trap)

– a sump where soil, sand, and debris settle
– prevents blockages in the pipe system

Inlets and outlets

– connections for drainage pipes, stormwater pipes, or downpipes

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Common Types of Stormwater Wells

1. Downpipe well

Receives water directly from a downpipe.

2. Surface drainage well

Has a grate at ground level.

3. Street inlet (curb inlet / road gully)

Located in streets—collects water from the roadway.

4. Stormwater well with sediment trap

The standard type for residential properties.

5. Chamber for stormwater cassette/tank systems

Used in larger systems with infiltration modules or storage chambers.