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.

  • Amount (acres) of functional floodplain
  • Amount (acres) of reconnected floodplain
  • Amount (miles) of publicly-accessible trails in and adjacent to floodplain
  • Type and extent of agricultural land use changes
  • Number of floodplain development permits and other specific developments
  • Amount (acres) of flood-compatible lands

Functional floodplain

How much floodplain is fully functional?

Floodplain areas have different levels of function based on land uses and intensities, infrastructure present, and other characteristics. Fully functional areas are essentially unaltered floodplains. These areas are connected to mainstem rivers, have no levee or flood control structures, provide flood storage, support natural vegetation, and have minimal land uses (such as passive recreation).

To track progress toward goals, a tiered system of classifying floodplains based on their level of function was developed. Classification of the entire FPA baseline extent is expected to occur in a future phase of this project. Increases in functional floodplain that result from floodplain reconnection projects will be tracked and measured against this baseline extent in future phases of monitoring. 

FFTF GOAL(S): Provide more space for the river to migrate
BASELINE YEAR: TBD.  FPA baseline extent of Tier 0 floodplain area to be calculated in future phase according to documented geospatial methods (see Monitoring Plan Attachment A). The entire FPA baseline extent includes 44,366 acres for the Puyallup watershed.
STATUS: None to report; baseline to be established in 2018
SOURCE(S): Floodplain Planning Area Tier 0 (GIS dataset to be developed)

Reconnected floodplain

How much floodplain has been reconnected?

Floodplain reconnection projects are a major component of FFTF attention and investment. These projects provide additional flood storage, mitigate flood risks to people and property, and recover refuge habitat for salmonids. The majority of projects are implemented by Pierce County Planning & Public Works as part of their ongoing program of floodplain reconnection and restoration projects as identified in their Rivers Flood Hazard Management Plan. Other local jurisdictions (King County, City of Sumner, City of Puyallup, City of Orting) also plan and implement projects in the floodplain to meet local objectives and the Pierce County Lead Entity for WRIA 10/12 implements floodplain restoration projects toward salmon recovery goals.

The total amount of reconnected or restored floodplain will be tracked and recorded from 2013 into the future to provide a measure of progress toward the FFTF goal of providing more space for the river to migrate.

FFTF GOAL(S): Reconnect floodplain to the river (at various flow levels)
Provide more space for the river to migrate
BASELINE YEAR: 2013 (First year of Floodplains by Design funding)
STATUS: TBD (Information still to be compiled and reviewed)
SOURCE(S): Habitat Work Schedule information maintained by Pierce County Lead Entity Coordinator with support from Planning & Public Works staff and project sponsors

Publicly-accessible floodplain

What are the opportunities for public access in the floodplain?

In addition to providing vital habitat and biological processes for the health and survival of salmonids, mitigating damage from floods, and supporting agriculture, floodplains can also provide recreational opportunities for the public. In the Puyallup watershed, major and minor trail systems occur in and adjacent to floodplains with more trails being planned for the future. The largest and longest system is the Foothills Trail, a wide non-motorized asphalt trail that begins in the City of Puyallup and runs through the Puyallup Valley to the City of Orting before beginning a small climb to the Town of South Prairie and City of Buckley. The trail terminates at the White River in Buckley. The future plan is to continue the trail to Puyallup where it connects with the Riverwalk Trail then ultimately to Tacoma and Sumner where it will connect with the Interurban Trail that now extends through Kent and Auburn. The trail in Buckley will continue east into King County and Enumclaw. More information and maps available at: https://www.piercecountywa.org/1384/Foothills-Trail

Nearly 22 miles of trail exist within the floodplain with an additional 63 miles proposed as part of the Pierce County Regional Trails Plan. A major portion of the trails plan is the regional Tahoma to Tacoma Trail Network developed by the Puyallup Watershed Initiative. https://www.pwi.org/index.cfm?fuseaction=page.viewpage&pageid=508

The Foothills Trail accounts for nearly half of the existing publicly-accessible trail in the floodplain and is present in the Middle and Upper Puyallup, Carbon and South Prairie Creek reaches. Other trails include the Hylebos Trail, White River Trail, and Enumclaw Trail.

FFTF GOAL:  Increase public access to floodplains
BASELINE YEAR:    As of 2018, a total of 22 miles of public access trail exist within the FFTF floodplain planning area
STATUS:    None to report; baseline established in 2018; status will be updated in 2023
SOURCES:   Pierce County GIS data - Regional Trails Plan GIS layer (2010)

Agricultural land use changes

How much floodplain is being converted into non-agricultural land uses?

FFTF Partners want to protect agricultural lands by prohibiting or limiting the conversion of existing lands in the floodplain to non-ag land uses. Conversion of land uses results in the permanent removal of the land from potential agricultural production. Authorized development within the regulated floodplain continues in the Puyallup watershed as part of the ongoing growth of communities and economies. Tracking the amount of land converted to non-ag land uses can be determined through a comparative analysis of property use codes managed by Pierce County.

In addition, the amount and number of parcels that occur within "organic hotspots" identified by the federal Organic Trade Association (OTA) will provide a federal benchmark for linking economic health at the county level to organic agriculture. OTA organic hotspots boost household incomes and reduce poverty levels — at greater rates than general agriculture activity. OTA organic hotspot boundaries are identified using zip code boundaries. More information about OTA's is available at: https://www.ota.com/hotspots

FFTF GOAL(S): Protect/conserve agricultural lands
Prevent conversion of agricultural lands to non-ag uses
BASELINE YEAR: 2018 (First year of reporting)
STATUS: None to report; baseline information to be established in 2018
SOURCE(S): Pierce County Assessor-Treasurer property use codes; Organic Trade Association (OTA) organic hotspots; City of Sumner and City of Puyallup permit databases

Floodplain development

How much development is occurring in the floodplain?

FFTF Partners want to make communities more resilient to flooding by prohibiting or limiting land uses in the floodplain that are not flood-compatible and/or result in the removal of floodplain functions. Development that removes natural land cover and results in impervious surface removes the ability of the floodplain to capture, store, and slowly release flood waters as well as provide habitat for fish and wildlife. Authorized development within the regulated floodplain continues in the Puyallup watershed as part of the ongoing growth of communities and economies. Tracking floodplain development is part of the annual verification and certification cycle of participants in the National Flood Insurance Programs (NFIP) Community Rating System (CRS). Development reported by CRS communities along with other specific developments (not captured as part of the CRS review) will be tracked and measured as indication of the FFTF progress toward prohibiting or limiting the loss of floodplain functions due to development.

FFTF GOAL(S): Make communities more resilient to flooding and reduce flood risk and damage to private property
BASELINE YEAR: 2018 (First year of reporting)
STATUS: None to report; baseline information to be established in 2018
SOURCE(S): NFIP CRS verification and certification information; Pierce County CRS Coordinator, City of Orting, City of Puyallup, City of Sumner permit databases (until CRS participation)

Flood-compatible uses

How much floodplain supports flood-compatible uses?

Any development in a floodplain has a risk of flooding and reduces floodplain function. However, some floodplain land uses are highly valued by the community and benefit from being located in a floodplain. For example, agriculture in the floodplain benefits from fertile soil and access to water. Where these uses can be periodically flooded without catastrophic damage to property or risk to public safety, particularly in more smaller and more frequent floods, they can be considered flood-compatible uses. For the purposes of this effort, flood-compatible land uses include agriculture, open space, and low density development.

To track progress toward goals, a tiered system of classifying floodplains based on their level of function was developed. Classification of the entire FPA baseline extent is expected to occur in a future phase of this project. Increases in the amount of flood-compatible land will be tracked and measured against this baseline extent in future phases of monitoring.

FFTF GOAL(S): Make communities more resilient to flooding and reduce flood risk and damage to private property
BASELINE YEAR: TBD. FPA baseline extent of Tier 1 floodplain area to be calculated in future phase according to documented geospatial methods (see Monitoring Plan Attachment A). The entire FPA baseline extent includes 44,366 acres for the Puyallup watershed (Tier 0-Tier 4 floodplains).   
STATUS: None to report; baseline to be established in 2018
SOURCE(S): Floodplain Planning Area Tier 1 (GIS dataset to be developed)