Over 100 people attended a forum on flooding hosted by the Salmon River Enhancement Society and the Fort Langley Community Association on May 22, 2013.
There were concerns about flooding in the uplands as well as on the flats near Fort Langley, the dumping of fill on farmland, and protection of the fish and habitat. Many of the questions dealt with development and the TWU/Wall farm development proposal in the watershed.
The panelists were Kevin Larsen, manager of water resources and environment for the Township of Langley, Dr. Marvin Rosenau, a BCIT fish and wildlife expert; Fort Langley historian Jane Watt; and Fort Langley farmer Tom Astbury.
Dr. Marvin Rosenau showed conclusively that clearing of trees, levelling and filling of land and residential development degrades rivers. Rainwater does not get into the ground. Detention ponds only limit maximum or peak flows but the total flow downstream is much larger and that damages the stream. Coho numbers fall.
The watershed of an ecologically important river is not the right place for development.
Flooding and farmers’ concerns
Less clear at the forum was what to do about flooding in the Fort Langley floodplain. As historian Jane Watt pointed out, the floodplain has always flooded. However the farmland is productive for hay which is quite resistant to flooding.
So should something be done for farmers?
There have been several measures. Drainage was increased in 1994 when a large screw pump was installed. To further mollify the farmers, the Department of Fisheries and Oceans (DFO) allowed the Township of Langley (TOL) to pump the river a foot below historic levels.
However, some farmers kept asking for more. They wanted the screw pump to operate year round and claimed, along with TOL, that the pump was not being operated in accordance with design. This argument is patently incorrect, but DFO capitulated.
With the ecological importance of the Salmon river, the 1994 agreements made it very clear that there would be NO approval for routine pumping outside the spring period when the Fraser River is in flood.
Meanwhile, the community has been totally shut out of recent negotiations between TOL and the farmers and the bill to the taxpayers is estimated to be $3 million and climbing.
Another screw pump?
Installing another screw pump to increase pumping capacity will not reduce flooding. Kevin Larson told the forum that the pump sometimes has to be turned off because the water is held up in the fields.
The floodplain is like a very large table top and the channel is so flat that the water doesn’t run fast enough to the pump at the mouth of the river. This is why engineering studies have shown that dredging will not improve drainage either.
The concern is that if another pump is installed, there will be unrelenting pressure from farmers to dredge because the second screw pump did not make a difference.