How Are We Improving Floodplain Health in the Puyallup Watershed?

We are learning how our communities interact with land in the floodplain

FFTF partners seek to understand the extent and changes in land floodplain land uses such as agriculture, floodplain restoration, public access, and development as a measure of the cumulative impact of policies, programs, and capital investments in integrated floodplain management.

  • Built Environment in the Floodplain
  • Actively Farmed Land
  • Connected/Natural Floodplain
  • Existing Climate Conditions
  • Accessible Stream Miles

This metric tracks changes in land-use in the floodplain using the Washington Department of Fish and Wildlife’s High Resolution Change Detection (HRCD) data. This dataset quantifies canopy loss, tracks changes in the amount of impervious and semi-impervious surfaces and provides information as to the likely cause of change, allowing FFTF partners to better understand interactions between communities and land in the floodplain. HRCD data is highly accurate and able to detect changes as small as 1/20th of an acre. "Built Environment" is defined as human dominated land cover such as roads, buildings, and warehouses.

 

2013-2015 Result: 350 acres of new built environment in the floodplain.

FFTF GOAL(S):All goals
BASELINE YEAR:2013-2015
STATUS:Baseline results established in 2019
SOURCE(S):Washington Department of Fish and Wildlife - High Resolution Change Detection Dataset

This metric tracks the amount of actively farmed land in the Puyallup watershed using Washington State Department of Agriculture land use mapping data merged with Current Use Agriculture parcels from the Pierce County Assessor.

 

2013 Result: 4,083 acres of actively farmed land in the floodplain planning area.

FFTF GOAL(S):
  • Protect/conserve agricultural lands
  • Maintain viable farming economy/critical mass of farmland and farm businesses
BASELINE YEAR:2013
STATUS:Baseline results established in 2019
SOURCE(S):Washington State Department of Agriculture: Land-use mapping data

Pierce County Assessor: Current use agriculture parcels

This metric tracks floodplain areas that are connected to the river or a tributary (i.e. do not have a levee, road, or other barrier between the floodplain and the river) and have natural land cover.

 

2013 Result: 21,078 acres of connected floodplain with natural land cover.

FFTF GOAL(S):
  • Protect existing functional salmon habitat
  • Increase the resilience of flood management infrastructure, the ecosystem, and agriculture as climate changes
BASELINE YEAR:2013
STATUS:Baseline results established in 2019
SOURCE(S):Washington Department of Fish and Wildlife: High Resolution Land Cover Dataset

This metric tracks five aspects of climate using gauges and historical records from within the Floodplain Planning Area.

  • Peak Streamflow
  • Low Streamflow
  • Winter Air Temperature
  • Water Temperature
  • Precipitation

Peak Streamflow Water Year 2018 Result: 26,200 cfs on October 22, 2017

Low Streamflow 2018 Result: 729 cfs on October 24, 2018

Winter Air Temperature 2018 Result: average December - February temperature of 46 degrees F. (1995 - Present average is 48 degrees F)

Water Temperature 2018 Result: The highest 7-day average daily maximum water temperature at the White River gauge was 20 degrees C

Precipitation 2018 Result: 37 inches of total annual precipitation

FFTF GOAL(S):All goals
BASELINE YEAR:2013
STATUS:Results from 2013 - 2018 established in 2019
SOURCE(S):USGS, Washington State University

The amount of accessible stream miles is critical to the health of salmonids in the Puyallup watershed. Barriers, such as culverts, can significantly restrict the amount of available habitat for salmon to spawn and feed. This metric will track the amount of stream impediments and quantify the amount of accessible stream miles in the watershed.

 

Data for this metric will be reported in the 2020 results cycle.

FFTF GOAL(S):
  • Restore historic function for spawning, foraging, and rearing habitat
  • Increase salmon abundance
BASELINE YEAR:2013
STATUS:None to report; baseline information to be established in 2020.
SOURCE(S):Washington Department of Fish and Wildlife