Sunday, November 23, 2014

Wetlands, Farmland and Drainage on the Nooksack Flood Plain

Before our November sunny break I headed north to Lynden and noted the water logged Nooksack River flood plain south of town. 
Nooksack River flood plain south of river and south of Lynden
The river was not flooding. The source of water standing over acres of land was the result of lots of local rain and poor drainage. The silty soils, high ground water and subtle topography cause water to accumulate in the fields.
The DEM of the area shows the problem of drainage on the flood plain - it is essentially uphill to the river.
DEM of Nooksack flood plain

The river is flowing from east to west and is the dark olive green sinuous line in the image. The straight tan line on the west half is Guide Meridian Road. I took the watery picture from my car looking east south of the river. Note that there are broad olive green colored low areas well back from the river both north and south of the river. The two south of the river are linked to the river via narrow streams and ditches that are barely discernible in the image. Otherwise these two low areas are separated from the river by a subtle but definite uphill slope. Each color shade corresponds to 1 meter in elevation.

Without the ability to keep the narrow ditches and stream connections to the river these fields would turn into swamp land or wet lands depending on your word selection. Water on the fields is not a problem in the winter, but if the fields remain wet deep into late spring, the farm land will be of little value.

The Growth Management Act requires counties to protect wetlands; however, there is a recognition that agricultural land should be protected as well. Under the local GMA required regulations Whatcom County critical areas regulations for wetlands allow the maintenance of drainage channels on farm lands. But the work on these drainage channels still requires State permits from the Washington State Department of Wildlife and the work requires a farm conservation plan.

1 comment:

Wendy Harris said...

Unfortunately, those farm plans are not subject to review or comment by the public, (unless there is a requirement to record some type of encumbrance to title), although they deal with issues of public health and safety. I for one would like to see more transparency in how the county deals with farm plan issues, particularly since there have been such major revisions to FEMA floodplain requirements.