Blog · Cambridge

How often should catch basins be cleaned on a Cambridge property, and why vacuum beats flushing

For most Cambridge parking lots and yards, catch basins need emptying once a year after the winter sand, with a second visit in fall on sites with heavy leaf drop or gravel. Street basins are the City's; everything on private property, from a plaza's double basins to a Blair driveway culvert, is the owner's, and the sediment has to be hauled away rather than flushed down the pipe.

Last updated October 24, 2026 · Reviewed by the Cambridge Hydrovac team

Where Cambridge storm water ends up

The City of Cambridge describes its storm system plainly: runoff enters catch basins, flows through storm sewers into stormwater management ponds, and is released slowly into local creeks and ultimately the Grand River. Oils, paints, chemicals and sediment that reach a storm drain follow the same path, and the City notes that what reaches the river can harm downstream drinking water. The City itself operates 47 oil-grit separators to trap pollutants before they get that far. On private property the same job falls to the owner's catch basins, sumps and separators, and a basin that is full of sand is not doing it.

Who cleans which catch basin in Cambridge?

The City cleans the storm sewer pipes and catch basins in the street as part of routine maintenance, and asks residents to keep the grates near their homes clear of leaves and trash to prevent flooding. A basin inside a parking lot, on a private road, in an industrial yard or at the end of a rural driveway is private, and the City lists a blocked private catch basin among the causes of drainage problems it does not fix. If a street basin is flooding, report it to the City. If the basin is on your lot, it is yours to maintain, and the catch basin and culvert cleaning service is what that looks like with a hydrovac truck.

How often should catch basins be cleaned?

Once a year, in spring, is the minimum for most Cambridge sites, because winter sand is the single largest load a basin takes. A second cleaning in late fall makes sense where leaf drop is heavy, which describes most of Galt and Preston's older streets, and on yards that shed gravel or fines. Oil-grit separators follow the manufacturer's interval, and on larger sites the site plan agreement sometimes sets its own. Two signs a site is overdue:

• Standing water in ordinary rain. The sump is full to the outlet, or the outlet pipe is choked with what overflowed from it.
• A dry basin with a hard, flat floor of sand just below the grate. The sump has filled completely and the basin is passing everything straight through.

Industrial yards along the 401, Pinebush and in Hespeler usually run a spring and fall schedule with the facilities group, timed to a shift change or a weekend so the truck can park within hose reach without stopping shipping.

Why the sediment cannot be flushed down the pipe

A cheap cleaning uses a jet to push the sediment out of the basin and down the outlet. That moves the problem downstream: into the next pipe, the pond, or the river. It is also a discharge the Region of Waterloo's Sewer Use By-law 21-036 does not permit. The by-law allows a storm sewer to receive only uncontaminated cooling water, storm water or uncontaminated water, and requires that no discharge obstruct the sewer or impair water quality in a natural water body. Catch basin sediment carries road salt, hydrocarbons, metals and fine silt, and from an industrial yard it may carry more. Vacuum cleaning lifts it out through the grate into the debris tank and hauls it to a facility approved to receive it, which for some yards means a facility that accepts potentially contaminated material. That disposal is part of the per-basin price, and it is the reason a vacuum clean and a jetting job are not the same service.

Oil-grit separators and the stormwater credit

Since July 1, 2025, Cambridge has billed a stormwater fee on water bills, and non-residential properties can earn a credit of up to 50 percent of the fee for measures that reduce peak flow and runoff volume and treat water quality, with the water quality treatment portion worth up to 10 percent. To qualify, the City asks for design drawings, specifications and operating procedures for privately installed measures, certified by a professional engineer, and credit agreements run up to five years. The City also points to provincial rules requiring operators of stormwater works to keep current operations and maintenance manuals and to keep records accessible for at least ten years. For a property manager, that makes a documented cleaning schedule for separators and basins part of the paperwork rather than a housekeeping chore, and a hydrovac operator who records what was removed from which structure on each visit is providing part of that file.

Culverts on Blair, Ayr and the rural edges

Driveway and laneway culverts toward Blair and Ayr silt up every spring, and a flooded driveway in April is the usual symptom. The vacuum pulls the silt and gravel out of the pipe rather than digging it out, so the driveway surface stays intact. One check comes first on river lots: much of Galt, Preston, Hespeler and Blair along the Grand and Speed rivers sits inside a Grand River Conservation Authority regulated area under O. Reg. 41/24, where placing or dumping material on a site or removing material from a site counts as development that can need a permit. Cleaning sediment out of an existing culvert is routine maintenance, but if the job turns into regrading a ditch or replacing the culvert, the GRCA's Map Your Property tool is worth a minute before anyone books a machine, and the GRCA says a permit usually takes four to six weeks.

What this means for your quote

Catch basin cleaning in Cambridge is quoted per basin for a site visit, with a site minimum and disposal included, and oil-grit separators priced individually because of their volume. What moves the number is how many structures there are, how full they are, whether the material may be contaminated, and whether the truck can park at each basin or has to run a long hose across a working yard. The Cambridge hydrovac cost page sets out how those stack. A site in the Pinebush and 401 industrial lands with forty basins and two separators is a different visit from a plaza with six, so send the site plan or a basin count and the operator will quote the schedule rather than a guess.

Sources

• Stormwater - City of Cambridge
• Sewer Use By-law 21-036 (PDF) - Region of Waterloo
• Permits - Grand River Conservation Authority
• Sewer - City of Cambridge