Arrow Lakes water levels to be below average for rest of summer

The Arrow Lakes Reservoir water level dropping and expected to be below average levels for remainder of summer.

The Arrow Lakes Reservoir water level dropping and expected to be below average levels for remainder of summer, BC Hydro announced on August 2, 2013.

“BC Hydro would like to advise that the Arrow Lakes Reservoir water level peaked at 440.0 metres (1443.5 feet) on July 3, 2013. Currently the water level is 436.5 metres (1,432.1 feet) and is dropping at about 0.6 feet per day,” read the announcement. The water level of the Arrow Lakes Reservoir will likely continue to drop this summer, according to current forecasts, and will reach a level between 431.2 metres and 434.3 metres (1,415 feet and 1,425 feet) by the end of August, said Hydro. These water levels are similar to those in late May 2013.

Work at the Mica dam replacing aging switchgear equipment has meant fewer generating units are running, so although water inflows into the Columbia River basin are expected to be about slightly above average this year, levels will be lower in the Arrow Lakes.

“Arrow Lakes Reservoir water levels are driven by numerous factors including snowpack, weather, load requirements, Columbia River Treaty provisions, and other variables and vary considerably from year to year,” said the press release from Hydro.

“What’s going out is driven by the CRT and other operating agreements,” BC Hydro representative Jennifer Walker-Larsen told the Arrow Lakes News. A summer storage agreement negotiated for this year with the U.S. for their fish is just one factor in negotiations, she said.

There needs to be mutual benefit in any agreement, said Walker-Larsen. If either the U.S. or Canada didn’t accept the terms, then there would be no agreement.

A lot of different levels of consideration go into operations planning, said the representative, such as the effects on fish, recreation, vegetation, plants and birds as well as flood control and power generation. BC Hydro and Bonneville Power Administration meet regularly in a treaty operating committee to discuss the agreements.

This year, the Arrow Lakes water level is low. Although it’s relatively uncommon, it is well within the historical range, said Hydro.

“Water levels on August 31 from the years 1968 to the present have ranged from a low of about 429.8 metres (1,410 feet) to a high of about 440.1 metres (1,444 feet),” read the Hydro press release.

For more information on reservoir levels and river flows, visit BC Hydro’s website. For more information on the Columbia River Treaty, visit for information about the review.

A point of clarification from BC Hydro representative Jen Walker-Larsen: the summer storage agreement was negotiated with the U.S. to help keep the Arrow Lakes Reservoir water level higher. Water levels in July would have been about five feet lower without the agreement in place.