The Ottawa backwater valve subsidy is a rebate from the City of Ottawa under the Residential Protective Plumbing Program. The City lists a maximum of $1,000 for an indoor backwater valve and $2,500 for an outdoor storm backwater valve. It also lists $1,500 for a battery backup sump pump in an existing pit. You must be eligible, get the permit and apply within the City’s time limit.
What the program is
The Residential Protective Plumbing Program (RPPP) helps Ottawa homeowners reduce the risk of sewer backup and basement flooding. The City pays a rebate after the work is done. It does not pay the contractor directly.
The program sits next to a by-law. The City’s Residential Protective Plumbing By-law No. 2025-89 sets the rebate schedule. The City’s Residential Protective Plumbing program page explains how to apply.
The program targets plumbing, not water that enters through the foundation. A backwater valve stops sewage or storm water from flowing back into your basement through a drain. It does nothing for water that seeps through a wall, a floor crack or a window well. That difference matters when you plan your budget, and we explain it below.
What the City lists as rebate maximums
These are the maximum amounts the City lists at the time of writing. They are not quotes. The City pays the lesser of the maximum or the actual cost of the work.
| Item | Maximum rebate listed by the City |
|---|---|
| Indoor sanitary backwater valve | $1,000 |
| Indoor storm backwater valve | $1,000 |
| Outdoor storm backwater valve | $2,500 |
| Primary or secondary sump pump with battery backup, existing sump pit | $1,500 per pump |
| Primary or secondary sump pump with battery backup, new sump pit built | $3,000 per pump |
| Building permit fee for the work | Rebated by the City, see the program page |
Older City documents and some contractor websites show lower amounts. For example, an older schedule shows $1,750 for an outdoor storm valve. The City updated the program, so use the current program page and by-law as your source. If a contractor quotes a rebate figure to you, ask where it comes from.
The City also gave a new time rule. The program page states that, from July 1, 2026, the time to finish the work and send in the application is 18 months instead of 12 months. The by-law text can still read one year. Confirm the correct limit with the City before you start.
Who qualifies
Eligibility depends on the age of the home and the type of device. The City sets these rules:
- The property must be a residential property in the City of Ottawa.
- Storm-related work generally requires a building constructed before January 1, 2004.
- Sanitary valve work generally requires a building constructed before January 1, 2012.
- The City does not give rebates to repair or replace an existing device.
- Funding is first come, first served within the annual City budget.
The last point is the one that catches people. A rebate is not a guaranteed entitlement. If the budget runs out, the City may not pay. Check the program page for the current status before you spend money.
How the process works
The steps below follow the City’s general process. The program page is the final word.
- Check eligibility. Confirm the age of the building and the type of device on the City’s page.
- Get quotes. Ask for a written quote that names the device, the permit and who holds the permit.
- Get the permit. The work needs a City building permit. Your plumber normally applies for it.
- Do the work and pass inspection. The City inspects the installation.
- Keep your paperwork. Save the invoice, the proof of payment and the permit.
- Apply. The City accepts an online application or a paper form. Send it within the City’s time limit.
Do not start work and then look for the rules. The permit and inspection steps affect whether the City pays. If you skip a step, you may lose the rebate.
A backwater valve is not waterproofing
Many Ottawa homeowners search for the subsidy after a wet basement. That is a reasonable first step, but the valve only solves one of the ways water enters a house.
| Water source | Does a backwater valve help? | What addresses it |
|---|---|---|
| Sewer backup through the floor drain | Yes | Backwater valve, plus a plumber’s assessment |
| Storm sewer backup | Yes, for a storm valve | Storm backwater valve |
| Groundwater pushing through a wall or the floor joint | No | Exterior or interior waterproofing |
| Cracked foundation wall | No | Crack repair or foundation repair |
| Sump pit failure during a power outage | No | Sump pump with battery backup |
| Surface water from poor grading | No | Grading, downspouts, window wells |
Ottawa sits on a mix of soils. Much of the city has Leda clay, a marine clay that holds water and can move with moisture changes. Spring melt along the Ottawa River and heavy summer storms can raise the water table and load the sewer. A home can have both a sewer backup risk and a seepage problem. In that case the valve and the waterproofing are two separate jobs.
A good first step is to find where the water came from. Look at the pattern. Water at the floor drain that smells of sewage points to a backup. A damp line along the wall base after rain points to seepage. If you cannot tell, ask a plumber and a waterproofing contractor to look. Their answers should agree on the cause.
Mould is a common follow-on problem after a flood. The City’s rebate does not cover mould removal.
Who does the work
A backwater valve is a plumbing device. Installation normally needs a licensed plumber because the work cuts into the building drain, and it needs a City permit. A waterproofing company may offer the valve as part of a larger job, or it may refer you to a plumber.
Ask these questions of any contractor:
- Who holds the building permit, and who is the licensed plumber?
- Does the quote name the device, the location and the model?
- Is the permit fee in the quote?
- Will you give me an itemised invoice that I can send to the City?
- What happens if the City inspector fails the work?
An itemised invoice matters. If one lump sum covers a valve, a drain repair and a new sump pit, the City may not be able to tell which part is eligible.
What our Ottawa boards show
Basementpros.ca does not install valves or do waterproofing. It ranks companies by Google rating and review count. The figures below are from our October 2026 data. They describe the companies on the boards. They are not an endorsement of any company.
| Board | Companies ranked | Median rating | Median reviews | Total reviews | Companies under 20 reviews |
|---|---|---|---|---|---|
| Basement waterproofing companies in Ottawa | 20 | 5.0 | 61 | 1,482 | 5 |
| Mold removal companies in Ottawa | 20 | 4.75 | 43 | 1,295 | 4 |
Three things stand out for a homeowner.
First, a median rating of 5.0 means rating alone does not separate most of the 20 waterproofing companies. Many have very high scores. Review count is the better signal of how much evidence sits behind a score. On the waterproofing board, the top five by our ranking run from 106 to 223 reviews, with ratings from 4.2 to 5.0. For example, Braden Foundation Construction shows a 5.0 rating on 106 reviews. The Foundation Guys Inc. shows a 4.2 rating on 223 reviews. A lower score on a larger count is not worse by default. Read the review text.
Second, five of the 20 waterproofing companies have fewer than 20 reviews. A 5.0 on a handful of reviews can change with one unhappy customer. Treat those scores with more caution.
Third, none of these figures tell you whether a company installs backwater valves or holds a plumbing licence. Ask each company directly. Many foundation firms focus on walls, drains and sumps and refer valve work out.
If you need mould work after a flood, see the mold removal companies in Ottawa board. For nearby areas, the same site has boards for Kanata, Nepean, Orleans and Barrhaven. For a wider view of the trade, see the basement waterproofing trade hub.
How to get quotes that you can compare
Whatever you plan, collect at least three quotes. Give each company the same description of the problem. Ask them to price the items separately:
- the backwater valve and its installation
- the permit fee
- any sump pit or pump work
- any waterproofing or crack repair
- restoration of the floor after cutting the slab
Separate prices let you see what the City might rebate and what it will not. They also stop a contractor from hiding a high waterproofing price inside a “valve package”.
Costs vary with the depth of the drain, the slab, access, the type of valve and the number of fixtures. We have no verified Ontario price range for these items, so we do not give one. Use your own written quotes and compare them to the City’s maximums. If a quote is lower than the maximum, the City pays the lesser amount.
Before you apply
Read the City’s current amounts and dates first. Confirm the age rule for your building. Get itemised quotes. Keep every invoice and proof of payment. The subsidy can lower the cost of protection against sewer backup. It will not fix a wet foundation wall. Plan for both risks, and pay for each in the right order.
Frequently asked questions
How much is the Ottawa backwater valve subsidy?
The City of Ottawa lists a maximum of $1,000 for an indoor backwater valve and $2,500 for an outdoor storm backwater valve. The City pays the lesser of the maximum or the real cost of the work. Check the program page before you buy, because the City has changed the amounts before.
Does the subsidy cover basement waterproofing?
No. The program covers backwater valves and sump pumps with battery backup, plus the related permit fee. It does not pay for exterior waterproofing, interior drains or crack injection. Those are separate jobs with separate costs.
Can I get a rebate for replacing an old valve?
The City states that rebates are not available to repair or replace an existing device. The program is for new protection. Ask the City to confirm your case before you start work.
Who installs a backwater valve in Ottawa?
A backwater valve is a plumbing device, so the job normally needs a licensed plumber and a City permit. A waterproofing contractor may subcontract it or refer you to a plumber. Ask who holds the permit before you sign.