Water Conservation During Weather Events

Wet Weather and Wastewater System Capacity

How rain and spring thaw affect Peterborough’s wastewater system

During periods of heavy rainfall or rapid spring snowmelt, large amounts of water can enter municipal sewer systems. In many communities with older infrastructure, stormwater and wastewater may travel through the same network of pipes. When major weather events occur, these pipes can fill quickly with rainwater and melting snow, increasing the total volume moving through the system.

Spring thaw can have a similar impact. As snow melts and groundwater levels rise, additional water can enter the sanitary sewer through foundation drains, cracks in pipes, or sump pumps and downspouts that are incorrectly connected. This extra water known as inflow and infiltration, adds to the amount of water that must be carried and treated.

When wet‑weather flows become extremely high, the wastewater system can approach its designed capacity. Municipal systems include safeguards to prevent basement flooding and sewer backups, which may allow excess water to bypass parts of the treatment process during severe conditions.

Reducing household water use during these periods helps limit the total volume entering the system and reduces the likelihood of these events.

Why temporary water conservation helps

During wet weather, wastewater treatment plants must handle both normal household wastewater and the additional stormwater entering the system. When many residents reduce water use at the same time, even for a short period, it helps:

reduce peak flows reaching the wastewater treatment plant
limit pressure on pumping stations and sewer pipes
lower the risk of sewage bypass events
protect local rivers and lakes from untreated wastewater

These actions are especially important during heavy rain, spring snowmelt, or when the City issues a temporary water‑use advisory.

What residents can do

Reducing indoor water use

Residents can help by making small, temporary changes such as:

delaying the use of dishwashers and washing machines
taking shorter showers
avoiding filling bathtubs
turning off taps when not in use

Manage water around your home

Preventing stormwater from entering the sanitary sewer system also makes a significant difference. Residents can help by:

ensuring sump pumps discharge outside, not into sanitary drains
keeping downspouts disconnected from sanitary sewers
directing roof drainage away from the foundation
maintaining private plumbing connections to prevent stormwater from entering the sanitary system

Reducing these sources of stormwater helps prevent unnecessary water from reaching wastewater treatment plants and sewer pipes.

Working together to protect local waterways

Peterborough’s wastewater system is designed to safely collect and treat wastewater from homes and businesses. However, heavy rain and spring snowmelt can temporarily increase flows beyond normal levels.

By conserving water during major wet‑weather events, residents help reduce pressure on the wastewater system and support the protection of local waterways.