Water pressure could be low and tap water slightly discoloured starting on Wednesday as crews repair a watermain damaged by a private contractor, the city says.

In a news release on Tuesday, the city said a watermain was damaged near Gerrard and Yonge streets on Monday. Emergency repairs are expected to begin at 7 a.m. on Wednesday.

Water service will not be interrupted, a safe water supply will be maintained, but repairs are expected to continue until April 30, the city said in the release. Repairs will take place downtown underground and no disruption to traffic is expected.

The city said water pressure could be low in the following areas:

College and Carlton streets to the north.

Dundas Street to the south.

Sherbourne Street to the east.

Spadina Avenue to the west.

The city said water will be rerouted through surrounding watermains to ensure a safe water supply to all customers.

"When this happens, the flow of water in other local watermains may change direction and become slightly discoloured due to disruption of iron deposits. To minimize discoloration, Toronto Water will be flushing local watermains in the area," the city said.

Water safe to drink, city says

The city said the water is safe to drink and any discolouration will not have a negative impact on health.

Residents in buildings less than four storeys high who notice the water is discoloured should flush the taps by running the water until it is clear, for up to 30 minutes.

Residents in taller residential buildings are told to call their property manager. If the water continues to be discoloured after flushing, people should call 311.

The city said minimal water pressure will be maintained while the watermain is repaired.

Residents who have no water, or extreme low water pressure, should also call 311.