Lowering the water level in Marsh Lake last spring wouldn't have altered the following summer's flooding problems, Yukon Energy has confirmed.

After meeting with more than 20 Marsh Lake residents Tuesday evening, Yukon Energy officials spoke to reporters Wednesday about the Southern Lakes Routing Study completed recently by Northwest Hydraulic Consultants.

The study determined how much water comes from each lake on the system, at what time of year and so on.

It also concluded the one area Yukon Energy has some control over Ð the starting water level in Marsh Lake in the spring Ð has no significant impact on the peak level in the summer.

Last summer, there was significant flooding in the Marsh Lake area, with damage to properties despite a huge volunteer effort to build sandbag barriers. Carcross and Lake Laberge were also affected.

Yukon Energy can have some control over the water levels in the spring when the company opens the gates.

However, Yukon Energy president David Morrison and Northwest Hydraulic Consultants' Bill Rozeboom, who was the project manager on the study, said there's so much water coming into the lake during the peak summer season that spring-time level is inconsequential.

While someone with a sink overflowing might pull the plug to release the water in it, the water is still only going to drain at a certain rate, they noted.

"If you had your two-inch water main pouring into your kitchen sink, your pulling the plug isn't going to stop your flooding because water cannot get out faster than it's coming in," Rozeboom explained. "And the reason the lake rises, it's the reason lakes change, is that rarely is the inflow equal to the outflow."

At Tuesday's meeting, Yukon Energy presented the findings that Marsh Lake's peak level each year won't be determined by what happens in the spring when the gates are opened.

"I don't think they were particularly happy to hear the news and, quite frankly, neither was I because we would like to get some additional storage on Marsh Lake," Morrison said.

After Tuesday night's meeting, he added, Yukon Energy will be going back to the residents in coming months with the answers to questions they had, such as what would happen if water levels in Schwatka Lake were drawn down during the summer.

"We know we can draw Schwatka Lake down," Morrison said. "We can draw Schwatka Lake down two or three feet in two hours, but what's the cost of doing that? Because remember: if we have less water in Schwatka Lake, it's a cost. The cost is we have less water to turn into hydro."

It's unknown what would happen upstream, he said, noting that's part of the question that will now be looked at.

While this study looked at what currently happens in the system, other work is being done to consider future options for Yukon Energy, he said.

The information gained through Northwest Hydraulic Consultants work will help determine the impacts possible measures could have on the overall system, he said.

"If we wanted to look at putting a control structure on Tutshi, for instance; well, prior to having the model, we wouldn't'know what would happen to the other parts of the watershed," Morrison said.

The study determined 40 per cent of the water in the system comes from Atlin Lake, 21 per cent from Bennett Lake and 18 per cent from Tagish Lake, with Marsh Lake contributing five per cent along with other water sources.

High run-off areas are on the western side of the system, while low run-off occurs on the eastern side, Rozeboom said.

Getting the information meant looking at the daily flow levels that were available from 1958 to 2005 with a more simplified analysis to consider last summer's flooding situation.

The study took about three months to complete, at a cost of $67,867.