What started a week or so ago as what could be considered a normal flooding event along Spengler Road has developed into a more significant event that may result in the permanent rerouting of the river. The Delta River, which is a glacier fed braided river that runs along the Richardson Highway, has been known to flood in various places from Summit Lake to its convergence with the Tanana River in the Big D area. The area where the river nears Spengler Road north of Delta Junction has flooded many times in the past.
Most of the past flooding has been rising water into lowlands along the river. The powerful river has also continually damaged the banks of the riverbed resulting in property loss along the river. Some property owners have lost as much as 50 feet of land to the river in the past 15 years.
This year the river took a different turn – literally – with the channel that runs along the eastern riverbank establishing a new path toward Spengler Road and the popular recreational area known as “the gravel pits.” The area has flooded many times as the river rose during the summer glacier melt and rains in the mountains upstream that feed the river. This year a new channel began to form bringing large quantities of water toward the gravel pit on the western side of Spengler Road. As the pit area became full and the water backed up against the rise north of the gravel pit, the water began to flow across Spengler Road and into the lowlands on the east side of the road.
As the water levels continued to rise and the opening to the Delta River continued to let in additional quantities of water, the water began to flow north along the east side of Spengler Road until it reached a high spot where it again crossed the road and began its path back to the main channel. The water also backed up to the south to Track D Road. The new channel cut a path across one residential driveway on the east side of Spengler Road, isolating the property.
The water collected into an existing slough that did not have the capacity to contain the water and the water became displayed into the low-lying land around the slough.
The high rate of water flow has created an increasing sized channel that is moving more and more water through the area, much of it at a rapid pace, presumably eating away at the ground under the flow and taking away soil, trees, and other debris in its path.
The resulting island between the new channel and the original riverbed has left three homes isolated and not accessible by normal means. One home, a mobile home, has water standing under the home.
As the water continued to flow north into the existing slough, it brought the water levels in the slough up and exceeded the slough banks and has flooded the garage of one home and threatens to flood the yard of two other homes. Volunteers with the Rural Deltana Volunteer Fire Department and the Civil Air Patrol worked Friday to place sandbags to help minimize the flooding potential on two of the homes. Once the flow of water was eliminated into the flooded garage, pumps were used to pump the water out of the flooded garage.
One of the homes along the slough is currently receiving groundwater into the basement of the home and is being removed by the homeowner.
On Thursday, the Department of Transportation and Public Facilities (DOT) began a remediation project to reduce the flow of water coming through the new channel where it breaks off from the old river bank, but abandoned the project on Friday after the channel expanded from approximately 50 feet to over 150 feet in width overnight.
Fire department personnel went out to the isolated homes on Friday in an airboat to assess the condition of the homes an assure that the homes were empty.
Water levels have become more stable in the area but continued to rise from Saturday into Sunday. The rise is estimated at about three inches overnight and the area of flooding has expanded. Officials continue to monitor the river flow and are prepared to take additional steps to protect homes if it becomes necessary.
The author is the Assistant Chief of the Rural Deltana Volunteer Fire Department and has been actively involved in the event both as the assist fire chief and as a part of the overall incident management team.