Cottagers and scientists disagree on Marten Beach flood cause

Pearl Lorentzen
Lakeside Leader

The November Slave Lake Forest Public Advisory Committee (PAC) focussed on the Marten Beach floods. The Marten Beach Cottage Association blame the floods on industry. Scientists blame climate change, geography, beavers and other factors.

Marten Beach was founded the 1950s. In 13 months (June 2018 to July 2019), Marten Beach suffered two catastrophic floods. Both left heavy layers of silt. The 2019 flood had higher water and more logs.

The meeting was Nov. 21 in Slave Lake, with 56 people in attendance.

The Marten Beach cottagers made a video after each flood and are peppering, Lesser Slave MLA Pat Rehn, and others with letters seeking assistance.

“We’re emotionally drained and frustrated,” said Valerie Tradewell, of the Marten Beach Cottagers Association. “All we want is some help.”

The MD of Lesser Slave River has spent a lot of money helping with clean up and getting flood mitigation estimates. The numbers they were given range from 20 to 50 million dollars, which is out of everyone’s budget. These range from building flood walls to buying out the properties and moving the community.

The association blames four years of intensive logging, cutting for pipelines, oil leases and gravel pits for the flooding.

Forestry land use information is available. It has 10, 20 and 200 year plans for log harvests. It is also required to seek input from stake holders, which is one of the reasons for PAC meetings. Other industries don’t have the same requirements.

For people interested land use by other industries, at some point the Alberta government plans to build a local land use plan. www.landbase.alberta.ca is the place the government of Alberta says has information on this process and how individuals can become stakeholders in it.

There’s been hydrology studies into the floods.

Hydrology is “a science dealing with the properties, distribution, and circulation of water on and below the earth’s surface and in the atmosphere,” says Merriam-Webster Dictionary.

Ahmad Asnaashari, hydrologist from Alberta Environment and Parks, and Dr. Axel Anderson, forest hydrologist from Alberta Agriculture and Forestry, spoke at the meeting. Their information was from studies done on Marten Creek and the area.

Storm intensity, ground saturation, the watershed (shape and type), climate change, and beavers were factors in the flood, said Asnaashari.

The weather information from two stations in the area, showed lots of rain in the month leading up to the floods and intense rain (over 300 mm) in the three days around the floods.

Beavers and residual damage from the previous flood in 2018, might explain the increased number of logs in 2019, said Anderson. In the 2018 floods, trees might have been disturbed. In the next flood, they fell and were washed into the creek.

Asnaashari looked at historic data from the Lily, Marten, and Brady Creeks which flooded in 1978, ‘87, ‘88, ‘96, 2011, 2018, and 2019.

In general, research attributes the increase in frequency and size of floods over the last few decades to climate change and urbanization, said Asnaashari. He looked at 60 years of flow data from the Sawridge Creek, which confirms that this trend is happening in the area. There are no flow metres on the three creeks. This means 100-year-flood calculations keep getting higher.

The percentage of trees harvested around Marten Creek was well under the percentage likely to have any impact on water flow, said Anderson. Also, the riparian (by the water) trees and shrubs are still intact.

Alberta has the most variable climate in North America, said Asnaashari. We have lots of very dry years and very wet years.

A watershed is the land all the water that drains into a creek or river.

The watershed shape can influence the amount of flooding, said Asnaashari. These watersheds are fan-shaped and have steep hills, which increase flooding.

Wetlands (i.e. swamps, bogs, muskeg, etc.) downhill from a creek, help decrease the intensity of floods, but uphill wetlands can increase the danger of floods, said Asnaashari. These creeks have uphill wetlands.

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