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Stormwater Open Curb Manhole Survey Preparation and Best Practices

Review the Tools and Conceptual Procedures to Conduct an Efficient Inlet Survey

All Fabco Industries Water Quality Inserts (WQIs) are manufactured to properly fit inlets by using specific information compiled in a survey of the “as-built” inlet. The Fabco Open Curb Manhole Survey form serves as the tool to provide that information.

In order to design and fabricate the stormwater filter devices for open curb manholes, Fabco must be provided with accurate measurements of the as-built inlet(s). The Open Curb Manhole Survey Form is designed as a tool for contractors (or others) to use to provide Fabco with the detailed measurements of the open curb manhole structure. Below is the start of the introduction to the survey form which will provide detailed instructions and insight into each field of the form that needs to be provided.

Survey Preparation and Best Practices

Recommended Stormwater Open Curb Manhole Survey Accessories


grate inlet survey guide suggested tools cameras

Photo documentation helps our engineers a ton when designing units for inlets with unique shapes, sizes or protrusions. Having a camera in the field is an extremely valuable tool. You don’t even need anything fancy, as now pretty much everyone is equipped with a great camera in their pockets at all times thanks to modern smart phones!


grate inlet survey guide suggested tools rulers

An important part of the open curb manhole survey is gathering the measurements of the inlet opening and any internal protrusions that might cause an issue when selecting or designing a unit to fit effectively.

Oil Pen

grate inlet survey guide suggested tools oil pen

When surveying multiple inlets for one job, using an oil pen sharpie marker to physically mark your inlets can be extremely useful. Not only does it help our engineers match up the photos you send them to the appropriate survey, it also helps the installation team know they are working in the right spot when it comes time to put the units in the inlet structure.

Wire Brush

grate inlet survey guide suggested tools wire brush

Stormwater inlets are rarely in mint condition when you show up to a survey site. Make sure you have a wire brush or something similar to help you clean the edges of the curb frame before recording any measurements to ensure you’re getting the most accurate information for our engineers.

Lifting Mechanism

grate inlet survey guide suggested tools lifting mechanism

Stormwater manholes are heavy! Use caution when lifting the grate from the inlet before recording your measurements. A crowbar or lifting hooks can assist you with removing the manhole without injuring yourself or a member of your crew.

Recording Catch Basin ID Numbers

Each catch basin should be assigned a unique ID number. Sometimes the numbers will coordinate with a site drawing, while on some projects, especially retrofits, the surveyor just assigns numbers in numerical order. The catch basin ID numbers provide guidance as to which unit is which, helps match survey images with submitted survey sheets, and provides guidance to installation crews for unit placement. A comprehensive ID practice will include the following:

grate inlet survey guide catch basin id number whiteboard

Use a small erasable whiteboard to identify catch basin ID numbers in photos. A legal pad or other paper can also work if you don’t have a whiteboard on hand. Adding the four side numbers also helps orient the photo to the survey forms.

survey preparation and best practices

An oil based marker will allow for marking the curb with the catch basin ID number to allow for easy identification of the catch basin at the time of installation.

grate inlet survey guide catch basin id cameras

Photo documenation of the inlet, especially those with protrusions or irregular characteristics, is a vital part of a comprehensive survey. Please make sure to have and use a camera of some kind.

Remote Assistance and Support

There is ample opportunity to incorporate current smartphone technology (iPhone or Android) with a variety of apps (Facetime, Duo, Google Meet, etc.) to provide real time site support on a survey. Please do not hesitate to reach out to Fabco Industries to schedule a remote support session. While these usually run smoothly, it is appreciated to get some lead time and test the communication prior to conducting the actual survey.

Please contact Warren Cohn, Fabco Stormwater Product Specialist, to set up your remote survey support: 484-689-1113 or [email protected]