All Years Spokane River (2015-2022)

All Years Hangman

2018 Hangman Creek Water Temperature

2018 Spokane River Water Temperature

2017 Hangman Creek Water Temperature

2017 Spokane River Water Temperature

2016 Spokane River and Hangman Creek Water Temperature

2015 Water Temperature Wrap Up

Focal causes of this issue are climate change, and a lack of healthy floodplains that contributes to the loss of essential riparian vegetation. Healthy riparian vegetation extends 35 to 100 feet from the river’s edge and consists of trees and shrubs. This vegetation helps to filter pollutants and provides shade that is imperative for creating suitable habitat for species such as redband trout, who thrive in cold water temperatures. One of the largest contributing factors to the depletion of riparian vegetation is the lack of cold groundwater that damages healthy flood plains along the Spokane River. Spokane’s aquifer, which is slowly being depleted with worsening climate change, coincides with river flows; as the water levels and temperatures of the aquifer changes, the river does as well. Cold groundwater produced by the aquifer is necessary for maintaining and producing healthy flood plains. Flood plains are necessary for the growth of Riparian vegetation because they provide soil with ample nutrients to foster plant growth and plant diversity. The Spokane River cannot flourish without ecosystem diversity.

In addition to habitat destruction and the effect of sediment loading on riverbeds, increasing temperatures have a profound impact on the decline of native redband trout in the Spokane River. The Spokane River is estimated to be populated with around 300 or less native redband trout per mile. These numbers have given the United States Fish and Wildlife Service incentive to deem the species as a “species of concern.” Given that the species are not restocked, they use the river and its tributaries as primary spawning grounds and are thus considered a “sentinel species” for the ecosystem. This means that they are used to detect environmental risks and hazards associated with humans. Additionally, they are considered a “barometer” for the river, meaning the species is used as a source to measure and indicate the aquatic health of the river environment. 

Trout require cold water; they seek habitat with deep pools and cold tributaries with lots of shade provided by riparian vegetation. Cold water is necessary for trout and other fish species because of oxygen. When water temperatures increase, the amount of oxygen available decreases. More available oxygen aids in the fish’s respiratory processes and makes the species less susceptible to stress. When temperatures exceed 64°F, trout tend to become lethargic. The lack of oxygen at these temperatures contributes to this nature; trout begin to move less to conserve energy and consume less resulting in a smaller biomass for the species overtime and decreased evolutionary fitness.

When we fish in high water temperatures, we contribute to the stress placed on fish. Fish undergo stress to consume flies, and stress from “fighting” our lures if hooked. As anglers, it is important to take into consideration the energy these species lose in the effort to swim to the surface and consume the “food” we provide. According to Sean Visintainer, the owner of Silverbow Fly Shop, encouraging individuals not to fish when water temperatures exceed 68°C is essential for maintaining safe catch-and-release practices, and the overall health of these species.

In addition to the Spokane Riverkeeper, many nonprofit organizations in the community continue to make efforts to address the issue of water temperature. One of the most impactful ways to combat the issue is through addressing the lack of riparian vegetation and promoting flood plain renewal. Local nonprofit groups such as the Inland Northwest Land Conservancy and The Lands Council continue to do great work in the Spokane River basin to promote habitat restoration and renewal. 

The Inland Northwest Land Conservancy works with landowners to protect lands that feed into Spokane’s aquifer. Through conservation easements, the organization works with private landowners to encourage conservative land use practices that protect shoreline habitat along the Spokane River and the threatened species that reside in these areas. 

The Land Council facilitates community-based projects and educational opportunities to protect the Spokane River, its wildlife, and continues to manage riparian restoration efforts. Within the last three years the organization has planted over 2,000 trees along Spokane’s waterfront, and continues to provide opportunities for the community to understand the river’s accumulation of hazardous substances as a result of unjust practices.

In addition to supporting nonprofit organizations in the Spokane area, you too can make an effort to address and mitigate this issue. Anglers can help minimize the stress trout and other fish species experience by reducing the amount they fish when river temperatures exceed 68°F. Getting involved in efforts to protect shoreline habitat through events hosted by the Spokane Riverkeeper and other organizations mentioned above is also important. As a community, we must also work to understand the severity of this issue. Educating ourselves on the effects of water temperatures on native species and the land we recreate on is an important first step to ensuring the flourishing of the Spokane River now, and in the future.