Heavy flows cause problems on Whychus

"A river channel is not large enough to contain all the water produced by a drainage basin in times of heavy precipitation. To flood - that is, to discharge in excess of channel capacity - is a natural characteristic of rivers. Thus, the flood-plain is an active part of the river during times of exceptional discharge."

So stated Luna Leopold, one of the leading hydrologists of the 20th century.

Most of the time, Whychus Creek gently caresses the landscape and whispers to those who live on its banks each night. But when the creek goes wild with 1,100-feet-per-second of meltwater rushing through Sisters - such as that generated by January's rains - people become a little edgy, and the elements of stream hydrology inextricably come into sharp focus:

• Floods are a natural phenomenon for rivers and streams.

• The floodplain is an active and vital part of a river or stream system.

• Efforts to alter the natural balance of stream slope, stream-bed roughness, and velocity and volume of flood water are likely to fail.

• Restoring meanders to impounded and/or straightened streams is becoming an increasingly accepted choice in flood management across the country.

• The open space of flood-plains adjacent to rivers and streams store and slowly release floodwaters, reducing peak flood flows downstream. Wetland areas act as large sponges, soaking up floodwaters in addition to filtering water and adding to groundwater supplies.

The Deschutes Land Trust and its partners, the Upper Deschutes Watershed Council and the Forest Service, have been working to restore Whychus Creek at Camp Polk Meadow Preserve for many years. More than 178,000 native plants have been reintroduced to help hold water when the floodplain is put into action.

"If a beaver were to build a dam (or two) on the creek. that would help expand the floodplain and help recharge some of the local aquifers as well," Deschutes Land Trust Stewardship Director Amanda Egertson said.

Among the many goals of the restoration has been to restore the natural flood-plain of Whychus Creek as it passes through the Camp Polk Preserve. If everything goes as planned, says Egertson, Whychus will be back in it's old meandering course in the flood-plain by the year 2012.

In the meantime, work will go on to bring about the restoration and creation of better fish habitat. The beaver living on Whychus Creek may contribute to the restoration of the floodplain and recharging of the aquifers throughout the Whychus drainage. Beaver back up water into the flood-plains, creating wetlands that serve as natural filters, absorbing nutrients and other pollutants from water and making rivers healthier for drinking, swimming, and supporting plants and animals.

The floodplain trees and plants placed throughout Camp Polk Meadow anchor river banks and prevent bank erosion. Those plantings stop the domino effect of erosion that leads to increased flood heights that results in raising sediments that raises the level of the riverbed as it settles.

Excess sediments cloud river water and coat leaves of aquatic vegetation, depriving them of sunlight. Too much sediment also directly impacts salmon habitat and human health by fostering the growth of bacteria.

Stream channelization causes changes to channel bed erosion and can lead to undercutting and destruction of bridges. Fire-hose velocity leads to uncontrolled bank erosion, and devastation of biotic fauna and aesthetic values. If Deschutes Land Trust can get the floodplain restoration task completed before the Sisters Country sees another 1,100 fps (or greater) discharge of meltwater in Whychus Creek, conservationists, irrigators and creekside residents alike will be happy.