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Control structure

Control Structure Manhole

Maintaining your control structure manhole requires a confined space certification and must be done by professionals. Control structures, also called flow restrictors, meter the release of stormwater from a facility at a specific rate. This helps to reduce erosion in local streams during rain events.

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A view inside a control structure manhole.

What you'll need:

DO NOT attempt to maintain your control structure yourself. Contact a professional with confined space certification. Find a list of professionals here

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The following steps shown are for educational purposes only. A professional should: 

Use a lit puller to remove the manhole lid for inspection.

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Measure the sediment levels of the sump and pump to remove, if needed.

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Inspect infrastructure inside structure and repair as needed.

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Reinstall manhole lid and provide you with a report of maintenance performed.

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Printable maintenance card

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Facilities commonly associated with control structure manholes:

Detention Pond 




Infiltration Basin 


Treatment Wetland