City investigating water outflow as Yellowknife forced to draw from bay to replenish reservoir

The City of Yellowknife is drawing water from Yellowknife Bay to "replenish reservoirs" as water flows out of a pumphouse at an unexplainably high rate.

The city said it is investigating the cause of the increased outflow from pumphouse 4 on Old Airport Road.

In an email, Abby Schelew, a spokesperson for the city, wrote that the city switched the raw source of water entering pumphouse 4 from Yellowknife River to Yellowknife Bay as of 5 p.m. on Tuesday.

Yellowknife River is the city's primary water source.

The City of Yellowknife is only typically allowed to withdraw a certain, limited, amount of water from Yellowknife Bay. In emergency situations, the city is allowed to exceed that amount. But the city files a document with the Mackenzie Valley Land and Water Board to inform the regulator about the withdrawal.

This document was filed by Chris Greencorn, the city's director of public works and engineering, on June 18.

"Due to the size limitations of the YK River pipeline, we cannot make water fast enough to replenish reservoirs to our comfort level given the current outflows," he wrote.

"We can draw at a much higher rate from Yellowknife Bay due to the larger intake size. With this downward trend in the reservoir at [pumphouse 4], we did not want to take any chances overnight."

He added that the cause is unknown, although it could be water breaks "or simply increased consumption due to a number of factors."

Schelew wrote that while the outflow from the pumphouse station is an "emergency" draw from Yellowknife Bay, the city is not low on water.

"Drawing water from Yellowknife Bay simply allows our distribution system to keep up with the increased demand."

She wrote that the city is undertaking several measures to determine the reason for the increased outflow of water, including sending out two separate leak detection crews to scan the pumphouse 4 service areas. There have been no reports of any failures yet, other than known issues that wouldn't cause the increase in water outflow.

Schelew wrote that an analysis is also being conducted on flow data from the water treatment plant and the pumphouse stations "to chart data trends to determine if the outflow is a result of increased consumption."

This is just the latest time the city has needed to exceed its water usage limits from the bay, as water main leaks led to withdrawals several times throughout the winter and spring.

The issues with water infrastructure come as the city put a pause on regulatory applications for a project to replace the pipeline that supplies the city with water.

The current pipeline was built in 1969 and is "nearing the end of its use," according to the city's website.

In a document filed with the Mackenzie Valley Land and Water Board on January 31, the city wrote that it decided to "pause all regulatory work related to the project at this time."

"Given the nature of the current budget uncertainties, the City requires more time in order to make long-term decisions."

Schelew confirmed on Thursday that the regulatory processes remain on pause as the city continues to seek additional funding.