North Fork Palouse River Water Quality
Water Quality of Tributaries to the North Fork Palouse River
The North Fork
Palouse Conservation District (PCD) has been working with landowners within the North Fork of the Palouse River (NFPR) watershed for over 20 years to integrate best management practices (BMPs) to tackle water quality issues relating to total maximum daily loads (TMDLs). TMDLs are the maximum amount of a pollutant allowed in a body of water without exceeding Washington State Water Quality Standards.
The NFPR is located on the east side of the Palouse River watershed and covers nearly 593 square miles (379,520 acres). Water flows from its source in the Hoodoo mountains, St. Joe National Forest, and connects with the South Fork of the Palouse River in Colfax, Washington. Major tributary streams and creeks that flow into the North Fork include Silver Creek, Clear Creek, Cedar Creek, Duffield Creek, and Brush Creek. The upstream landscapes of the watershed are mainly evergreen forest with small amounts of shrubs and cultivated crops. This changes drastically as we move west and downstream, where almost all landcover becomes cultivated crops.
History of Agriculture in the Palouse Watershed
1805
Prior to European settlement, the Palouse region was primarily occupied by the Palouse (Palus) people. Lewis and Clark first met the Palouse Tribe in October of 1805.
1850
The Palouse people were removed from their land after the first European settlers arrived on the Palouse.
Late 19th Century
European settlers arrived on the Palouse to utilize the fertile loess soils. Initially, grazing and fruit crop cultivation were the primary land uses. However, it was later realized loess soils were ideal for grain production.
1905
The hills of the Palouse were steep and could cause standard tractors or combines to tip. The Idaho Harvester Company of Moscow began manufacturing small combines in 1905 that could be used on the Palouse hills.
Late 1920's
Soil erosion became a major concern due to plowing of the steep loess hillsides. It was feared that if not addressed, erosion could bring farming on the Palouse to an end.
1930s
By this time, 90% of all wheat was harvested by combines.
1930-1970
Agriculture on the Palouse became highly mechanized and industrialized. A combination of advances in petroleum-based technology, wheat breeding, and the introduction of fertilizers after World War 2 resulted in increases in crop production by 200-400%.
1937
The Standard State Soil Conservation Districts Law was passed, authorizing the establishment of "soil conservation districts" across the country.
1940
Palouse Conservation District was formed to provide assistance to landowners to prevent soil erosion and conserve natural resources.
The Palouse has historically had some of the highest wheat yields in the US. As a consequence, the region also has some of the highest erosion rates.
Water Quality
Land cover changes from native prairie to urban development and dryland agriculture have resulted in water quality reduction in the North Fork and many of its tributaries. Furthermore, it has affected a number of fish, wildlife, and plant populations, leading them to become threatened.
The focus of the PCD's NFPR project is on nonpoint source pollution (pollution that can't be traced back to a single source). Examples of nonpoint source pollution include agriculture, livestock, sewage treatment system failures, storm water, and wildlife.
Water Quality Atlas
This map displays water quality impairments, as designated by the WA Department of Ecology, for the North Fork and its tributaries. Creeks in this map are broken into 6 categories and subcategories described below.
Category 1: Meets tested standards for clean water Category 2: Water of concern Category 4A: Impaired water that already has a TMDL plan implemented and approved by the EPA Category 4B: Has a pollution control program in place Category 4C: Is impaired by causes that cannot be addressed by a TMDL plan Category 5: Polluted water that requires an EPA approved water improvement plan or TMDLs, this is known as the 303(d) list
Study Background
The North Fork is listed by the State of Washington under section 303(d) of the Clean Water Act for exceeding Washington State fecal coliform, pH, temperature, dissolved oxygen, and toxics standards. This study aims to assess effectiveness of conservation measures installed to meet TMDLs and identify potential hotspot sources of pollution.
Project Goals
This project has 3 main goals:
- Quantify changes in water quality parameters that demonstrate the impacts of riparian buffer and livestock exclusion projects on water quality.
- Assess changes in sediment, nutrient, temperature, and fecal coliform concentrations and loads.
- Identify tributaries of the North Fork that have high sediment, nutrient, temperature, and fecal coliform concentrations and loads.
Monitoring
For the study, eight sampling locations were set up to monitor changes in water quality with the goal of quantifying the impact of BMPs, such as riparian buffers and livestock exclusion projects.
Each site is visited once a month, and data is recorded from various sensors. Additionally, water samples are sent to the lab to be tested for the presence of nutrients and pollutants.
How do we Monitor?
Different approaches are used to measure water quality. Grab samples of water are taken from streams, and equipment with sensors are used to measure stream discharge and water quality metrics like temperature, pH, conductivity, dissolved oxygen, turbidity, nutrients and sediments. If you want to learn more about what water quality metrics we measure and why, head to the link below.
How can I Contribute?
Confluence Crew is a citizen science water quality monitoring program run by PCD. This program aims to educate and provide tools to our community on how to preserve our water resources while allowing opportunities to engage in participatory research. Another goal of Confluence Crew is to ensure our community has access to up-to-date water quality information about their local waterways. If you are interested in being involved in this program, please visit the link below.
Data and Analysis
Data collected is shown in this interactive web-application. Select a parameter and one of our monitoring sites to explore the data.
