Water Quality Improvement Projects (TMDLs) > WRIA 24 > Willapa River Watershed  Multi-parameter Project

Water Quality Improvement Project
Willapa River Watershed Area:
Multi-parameter

Introduction

The Willapa River watershed is located in Pacific County, Washington State, in Water Resource Inventory Area (WRIA) 24.

The Willapa River drains a region of about 260 square miles. The watershed has been the subject of several water quality studies since 1998. The studies involved 303(d) listings for dissolved oxygen (DO), fecal coliform bacteria (BacT), and temperature (T) conditions. The watershed is mostly rural except for the cities of Raymond and South Bend. Principal industries in the cities are lumber mills and seafood processing (mostly oysters). Agricultural land uses predominate in the river valley, and forestry is the main use throughout the rest of the basin. There are about four commercial dairy operations in the basin, and many smaller livestock operations for beef and young stock.

For study and cleanup planning purposes the river was split into upper and lower river segments. The tidally influenced lower river portion behaves differently from the upper river. The lower Willapa River is a tidal estuary characterized by the mixing of Willapa Bay marine waters with fresh water from the river and other tributaries. Depending on the river flow, tidal effects cause saline marine water to move as far upstream as Camp One Road at River Mile (RM) 14.5.

Water quality issues

Pollution concerns were documented in several Willapa studies by various organizations with interests beyond total maximum daily loads (TMDL). Low DO and higher temperatures were determined to be limiting factors affecting the aquatic habitat and fish in the Willapa system. BacT levels are high enough during certain periods to violate standards set for protection of shellfish harvest outside the river mouth. During certain periods BacT levels are high enough at several other places to violate standards set for protecting people during swimming or other recreation in the river.

© Joe Mabel.

Why this matters

Oxygen dissolved in healthy water is vital for fish and aquatic life to “breathe” to survive. It is more difficult to transfer oxygen from water to blood than it is to transfer oxygen from air to blood. Therefore, it is critical that an adequate amount of oxygen is maintained in the water for this transfer to take place efficiently and sustain aquatic life. Oxygen is also necessary to help decompose organic matter in the water and bottom sediments as well as for other biological and chemical processes.

Fecal coliform is a type of “bacteria” common in human and animal waste. It indicates that sewage or manure is entering a water body. As the level of fecal coliform increases, the risk of people getting sick from playing or working in the water increases. Bacteria can get into our waters from untreated or partially treated discharges from wastewater treatment plants, from improperly functioning septic systems, and from livestock, pets and wildlife.

People can help keep bacteria out of the water. Properly collect, bag, and trash dog poop. Check your on-site sewage system to make sure it is maintained and working properly. Ensure livestock and manure are kept away from the water.

Water temperature influences what types of organisms can live in a water body. Cooler water can hold more dissolved oxygen that fish and other aquatic life need to breathe. Warmer water holds less dissolved oxygen. Many fish need cold, clean water to survive.

One way to cool water temperature is to shade the water body by adding or retaining streamside vegetation.

Status of the project

To address the fishery resource concerns various organizations are helping to protect and enhance the riparian corridor. Landowners, the local conservation district, and local fishery support groups provide land and plant materials for stabilizing the stream banks and increasing plant cover and shade. Increased shade is the most important feature to improve temperature and help improve DO in the upper river. Landowners install fencing to keep livestock from eroding the banks and plant more trees to increase shade and help intercept animal waste or other sheet erosion to keep it out of the river.

In the lower river, where DO stress was found to be caused naturally, facilities are controlling their discharges so they do not add to the DO problems. To adopt the DO TMDL, the cities (treatment plants) and three seafood processor facilities signed a unique partnership agreement that they will closely monitor and collectively limit their discharges so that DO will not be lowered by more than 0.20 mg/liter during the spring and summer periods.

A water quality implementation plan (WQIP) for temperature was sent to EPA in 2004, and for DO in 2005.

A WQIP for fecal coliform bacteria was sent to EPA in  2008.

Technical information

Willapa Project Studies and Cleanup Plan Reports

• Willapa River Total Maximum Daily Load Data Summary Report (Ecology publication)

Dissolved Oxygen:

• Willapa River Dissolved Oxygen Total Maximum Daily Load: Water Quality Improvement Report and Implementation Plan (Ecology publication)

Fecal Coliform:

Ecology submitted the final WQIP to EPA on August 15, 2008.

Willapa River Fecal Coliform Bacteria Total Maximum Daily Load:  Water Quality Implementation Plan

• Willapa River Fecal Coliform Bacteria Total Maximum Daily Load: Water Quality Improvement Report (Ecology publication)
  • Lower Willapa River Fecal Coliform Bacteria Total Maximum Daily Load Evaluation (PDF)
  • Analytical Framework and Technical Analysis for the Upper Willapa River Fecal Coliform Bacteria TMDL (PDF)
  • Willapa River Fecal Coliform Bacteria Verification Study: Water Quality Monitoring Report (Ecology publication)
• Willapa River Microbial Source Tracking Study Report:
  • Willapa River Monitoring Report, 6/24/2005 (PDF)
  • Appendix A (PDF)

Temperature:

• Willapa River Watershed Temperature Total Maximum Daily Load Study (Ecology publication)
• Willapa River Watershed Temperature Total Maximum Daily Load (Water Cleanup Plan): Submittal Report and Detailed Implementation Plan (Ecology publication)

Related information

Habitat Limiting Factors Executive Summary:  Water Resource Inventory Area 24 - Willapa Watershed (WA State Conservation Commission)
www.scc.wa.gov/index.php/Download-document/278-WRIA-24-Willapa-River-Basin.html

WRIA 24 Watershed Information (Environmental Assessment Program web site)
www.ecy.wa.gov/apps/watersheds/wriapages/24.html

Ecology Publications for WRIA 24 (Ecology publication)

Back to top of page