Roadside ditch progress

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Rawley, DD10 Commissioner, shows the depth of decomposing reed canarygrass in a roadside ditch.

Pierce County Roads division has been expressing interest in understanding how better to support improved agricultural drainage by re-visiting their maintenance schedule and methods. Typically, their crew visits a few times a year, mows down the grass (mostly reed canarygrass or blackberries) and departs. However, this leaves piles of debris in ditches, which may eventually make their way to a culvert, and may only partially decompose, therefore blocking water from draining from the ditch. They’re now seeking a few locations to try out alternative methods, including cutting grass shorter, removing debris, and/or placing a mat down to block weed growth. They’re also open to conducting a survey of the ditch to remove high/low spots to improve flow!

Let us know if you know of any ditches that drain agricultural fields AND are maintained by Pierce County Roads department, and we can connect you with the right folks!

A roadside ditch filled with lush reed canarygrass. We’ll follow the progress and hope to see improvement in flow!

FFP: what’s going on with drainage?

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The Floodplains for the Future partnership is awaiting funding from the third round of Floodplains by Design funding, but the partners are already working hard to move projects ahead. One project that the Farming in the Floodplain Project is excited about is the opportunity to improve agricultural drainage in the Clear Creek area by reconnecting floodplain and restoring Clear Creek on a ~30+ acre parcel of property now owned by the County. Drainage District 10 will be a part of this effort, and in order to make informed, data-backed decisions about how to restore this property, we’re collaborating with flood and fish interests to collect information that will point this effort towards success.

This means collecting data about:

  • surface and groundwater levels in the Clear Creek basin- what do water levels look like over the course of a year?
  • the hydraulic grade line- what’s the slope from one end to the Puyallup River- is it enough to drain the basin?
  • the amount of water the four tributaries (Swan, Squally, Clear, and Canyon Creeks) contribute off the plateau onto the floodplain- how much water is coming off the plateau and draining through the floodplain?
  • salinity- is saltwater water from downstream making it to this system during high tides?

We’re all working to figure out how to share resources and existing equipment in order to collect this data. The end result will be a way better understanding of how water moves around Clear Creek, which will give us all a better path forward to integrating agricultural drainage elements into this restoration project. For example, “re-meandering” Clear Creek by un-pinning it from the railroad tracks could improve flow and water storage. Understanding the slope of the floodplain within the creek/ditch system can show us where to focus efforts to clear, widen, or alter the ditches.

For more information about this effort, or about the Farming in the Floodplain Project, email Jordan.