Project Summary:

mouth Hangman Creek dumping sediment in Spokane RiverCitizen scientists from Spokane Falls Trout Unlimited will monitor water clarity (turbidity) in the Spokane River and Hangman Creek.  This data will be used to determine the intensity and duration of degraded water quality in Hangman Creek and its effect on the Spokane River.

Background:

Hangman Creek has suffered extreme degradation in the form of loss of riparian habitats and function, ditching of wetlands and loss of wetland function, as well as excessive drainage systems originating in agricultural operations and running into the creek. Additionally the Palouse loess soils have been routinely exposed through tillage practices that exacerbate erosional runoff of sediment and phosphorus. (ref)  As many as 200,000 tons of top soil run off and into Hangman and the Spokane River each year.  Hangman has been studied but the Spokane River has received little attention to the impacts of sediment inputs on the aquatic biology of the Spokane River system.

mouth Hangman Creek dumping sediment in Spokane RiverFew if any agencies or scientists are watching the phenomenon of sediment entering the Spokane River seasonally from Hangman Creek each year.  Little is understood about the amount of sediment, its origins, or the implications for disrupting Redband trout spawning, feeding behavior or the substrate that provides habitat requirements for salmonids and other fish.  Additionally, little is known about its impacts on the benthic community, and its contribution to the nutrient loading in the Spokane’ river system.  This sediment input can be assumed to change the trophic response and behavior of the river system in a multitude of ways.

Washington State Department of Ecology currently samples at the mouth of Hangman Creek and downstream of the Hangman mouth at the Spokane River at Riverside State Park and at the Nine Mile Bridge.  These data, from monthly sampling events, suggest that turbidity from Hangman Creek influences the Spokane River.  Hangman Creek is notoriously flashy watershed, sometimes rising and falling thousands of cubic feet per second in a day, bringing with it the associated sediment.  Monthly sampling is not sufficient to capture these flashy events.  More frequent sampling will record the intensity and duration of Hangman Creek’s sediment plume in the Spokane River.

Methods:

Map Spokane River sediment study locations

Sampling locations for turbidity study on Hangman Creek and the Spokane River

Turbidity readings will be taken twice per week from Hangman Creek and the Spokane River above and below the mouth of Hangman Creek between December 1, 2017 and June 1, 2018.  Samples will be taken in Hangman at Peoples Park or the 11th Street Bridge and in the Spokane River at Sandifur Bridge and below the TJ Meenach Bridge.  Turbidity will be determined using a transparency tube and recorded in centimeters.  Readings will be taken twice per week, preferably on Monday and Friday.  Readings from Sandifur Bridge samples will be compared to readings from the TJ Meenach samples to determine the effect of Hangman Creek on the Spokane River.

In locations where the river/creek is not accessible from land, a jar/bucket will be lowered into the water with a rope off of a bridge.  Water will be hauled up in the container and analyzed for turbidity.

 


 

Photo Documentation of Sediment Plume
mouth Hangman Creek dumping sediment in Spokane River

Example photo from photo point at corner of Summit and Broadway

Volunteers will take photos of the sediment plume from the corner of Summit and Broadway on the Centennial Trail during each monitoring run.  Photos will be combined to visually show the impact of Hangman Creek on the Spokane River.

Results will be recorded on the datasheet included below.  Make sure to note weather patterns or unusual results in the notes section.

Training and Reporting

Staff from the Spokane Riverkeeper will train volunteers for the first time on Wednesday December 13th and again at future date, like in January 2018.  Volunteers will report results back to the Spokane Riverkeeper weekly.

Safety

The safety of volunteers should take priority over any data collection.  Please do not attempt to take water quality samples in slippery conditions, such as on ice or snow.

Project Outline:

Sampling water clarity (turbidity) Spokane River at mouth of Hangman Creek

Sampling water for clarity (turbidity) data

Citizens would collect flow, turbidity and photo data at points along the Spokane River and Hangman Creek through the winter of 2017/18 and into the summer or 2018

1. Volunteers would collect turbidity/transparency data:

  • Above confluence with Hangman Creek in the Spokane River at Sandifur Bridge
  • Mouth of Hangman Creek at 11th Street Bridge
  • In main stem of Spokane River at TJ Meenach Bridge

2. Volunteers will take a photo at photo points:

  • Confluence of Hangman Creek
  • Possibly TJ Meenach Bridge

Project timeline:

  1. Volunteers would gather data between December 1, 2017 and June 1, 2018
  2. Monday and Friday every week
  3. Data would be written up and disseminated to interested parties and collected for Spokane River DO TMDL 10 year assessment input

Potential Future Research Questions/implications:

  • What are the impacts of excessive sediment pollution to O Mykiss habitat and behavior?
  • What are the impacts to the benthic invertebrate communities that provide a food base for native fish, what are the effects on non-salmonid native fish in the food web, effects on algae growth and dissolved oxygen in aquatic systems/River.

Background:

mouth Hangman Creek dumping sediment in Spokane River

Flood and nonpoint sediment pollution in Hangman Creek entering the Spokane River, February 2017

Summer 2016 Spokane River sediment

2016 summer photo of substrate below Hangman confluence in Spokane River (prior to February 2017)

Summer 2016 Spokane River sediment

2016 summer photo of substrate below Hangman confluence in Spokane River (prior to February 2017)

Summer 2017 Spokane River sediment

2017 summer photo of substrate below Hangman confluence in Spokane River (post February 2017)

Summer 2017 Spokane River sediment

2017 summer photo of substrate below Hangman confluence in Spokane River (post February 2017)

 

Transparency/Turbidity Data Sheet

Volunteers will input data on the paper form and submit that data online here.

Location Date Time Transparency/Turbidity Reading (cm) Flow (CFS) Notes (rain, snow, unusual river levels)