Domestic water use reduces river flows

Listen to Jerry White on KREM2 explain our aquifer and how domestic consumption affects river flows.

Read the Water Resources Collaboration Group final report in slide form, which does a great job of outlining the water conservation recommendations for the City of Spokane.

Hydrograph of recent 14 days of 00060 streamflow at 09380000

Listen to our podcast about the aquifer

Or watch another great overview from KREM 2.

 

Low flow in the upper Spokane River, early September 2021, at Barker Road. This section of the river loses water to the aquifer and flow is dependent on surface water from Lake Coeur d’Alene.

THE ISSUE AT A GLANCE

The United States Geological Survey has been recording flow rates in the Spokane River since 1891. Over the last 130 years, there has been a steady decline in river flow, specifically in the spring and summer months. Higher temperatures are reducing the amount of snowpack in the mountains, leaving less water to contribute to spring and summer river flow. Recurrent droughts are reducing the overall amount of precipitation that reaches the river and increasing irrigation demands for aquifer water in the summer months. Increased summer pumping diminishes aquifer water available for maintaining flow and coldwater fish habitat in gaining reaches of the river. Basin-wide efforts to conserve and reduce consumption of water are crucial if we are to sustain the flowing waters of the Spokane River.

Click here for a presentation on the change in Spokane River flow over the last 130 years.

RIVER-AQUIFER CONNECTION

The Spokane River is hydrologically connected to the Spokane Valley-Rathdrum Prairie (SVRP) Aquifer. The SVRP Aquifer provides water for over 600,000 people in Spokane and Kootenai counties. We know the river is the largest source of recharge for our water supply, providing 43% of aquifer inflow annually. The aquifer is also an important source of water for the river, contributing 60% of its annual outflow.

See our Presentation on the River SVRP Aquifer connection here and understand the impacts of climate change and municipal pumping.

Low flow in the lower Spokane River, August 2015, at Bowl and Pitcher, Riverside State Park. This section of the river receives water from the aquifer. However, during the drought of 2015, flow here was still extremely low.

Photo credit: Sierra Club

Watch how flow in the Spokane River changed during the drought of summer 2021.

In the drought year of 2015, the Department of Ecology studied the influence pumping from the SVRP aquifer has on the Spokane River. When water is drawn from the SVRP aquifer, the amount of water flowing in the Spokane River decreases. The Spokane River is more than a beautiful sight – it is a place of recreation, a natural habitat for many species of fish and invertebrates in our region, and a prominent symbol in Spokane’s cultural heritage. The more water Spokane takes from the aquifer, the more likely the recreation and ecology of the river will be threatened. Therefore, the need to address water conservation in our city is vital for the future of our river, and all that it supports.

Check out the science from the 2015 drought here.  Check out the 2018 Water Forum for more info on river/aquifer interaction and perspectives on conservation here.

WATER CONSUMPTION & Drought

The average American household uses 138 gallons per day, according to a 2016 study. Between the years of 2015 and 2019, single family homes in the City of Spokane were using an average of 117 gallons per day in the winter months, but in the summer water consumption climbs to an average of 587 gallons per day. Outdoor watering of lawns and home gardens is the main cause of of high water usage in the warmer months. Average daily domestic water use per person in Spokane County is 235 gallons per day, which is almost three times the national average of 82 gallons per person per day. In Kootenai County, usage is even higher at 251 gallons per day.

Increased human water consumption leaves less cold aquifer water for the river needed to maintain summer water temperatures and flow, shrinking available habitat for native coldwater fish, like Redband trout.  It is estimated that summer pumping from our aquifer reduces flow in the river by 120 to 175 cubic feet per second. The problem is compounded during years of drought, like 2021, when flow in the river is already exceptionally low. Human population growth in Spokane and Kootenai counties will place additional demands on regional water supplies, further impacting the river.

Waste from inappropriate lawn irrigation. Established grass typically only needs water every three to five days and irrigation should be slow enough to allow the water to percolate into the soil.

 

Click here to review the Spokane Sustainability Action Plan adopted in 2021 by the City Council.

COMMUNITY SOLUTIONS

As a watershed, we need collective efforts to use water wisely and conserve water for the river. In 2020, the City of Spokane had set a new goal for 5% reduction in per capita (per person) water consumption and a 15% decrease in seasonal peak demand by 2030. Spokane Riverkeeper supports a more ambitious goal for 2022, of 25% reduction in annual aquifer pumping (from 2015-2019 average) over the next ten years. We are also advocating for a Drought Response Plan, triggered by low flows in the Spokane River, that calls for voluntary and mandatory restrictions on outdoor water use (e.g., irrigation, car or hardscape washing).

On June 6th, 2022, the City Council of Spokane passed a landmark ordinance - C36209 - that codified a water conservation and drought response plan for the City of Spokane. It took a historic override of Mayor Woodward’s veto of the water conservation ordinance.

This is a far-reaching plan that is remarkable in that it listens to the river and its flows to provide triggers for conservation and drought response actions. When the River recedes under 1000 CFS, actions are initiated to limit ground-water pumping and reduce municipal demand of the cold water that our River needs to sustain life during our hot summers. This is a major turning point in assuring that our River will be climate-resilient in the future.

This plan is the result of nearly two years of work on the part of a “Water Resources Collaboration Group” composed of stakeholders resulting in conservation and drought response guidance. This guidance informed the City Council as they then considered codifying water conservation options.

The Spokane Riverkeeper was one of the leaders of the WRCG developing guidance that will protect river flows that are dependent on this is aquifer water and support a fragile population of redband trout, and the Upper Columbia Tribal visions and actions of restoring chinook salmon to the basin.

These measures will be an integral part of this historic movement toward our communities recognizing our groundwater is not endless, but is critical to the health of our River now and for generations to come.

WHAT CAN WE DO

In addition to supporting water conservation and drought response planning in our communities, there are several ways we can save water for the Spokane River.

  • Replacing lawns with native, drought tolerant vegetation

  • Smart irrigation practices and systems

  • Replacing old fixtures and appliances with water efficient or low-flow models

  • Restoring riparian habitat with native trees, which provide shade for the river and reduce evaporation

  • Protecting and restoring wetlands that provide aquifer recharge and improve flow in the river

  • Using reclaimed water for irrigation

  • Developing a tiered water rate structure that incentivizes and encourages wise water use

  • Supporting industrial practices that use water more efficiently

  • Placing conserved or unused water rights into a trust that benefits instream flows for the river

Wise use of aquifer water is a priority to sustain river flow, protecting important aquatic ecosystems, cold-water habitat for native redband trout and future salmon reintroduction, recreation opportunities, and the natural beauty of our iconic Spokane River.

 

Restoration to wetlands like Saltese Flats will provide water storage and aquifer recharge, improving late summer river flow.

references

City of Spokane Water Department. (2020). City of Spokane Water Conservation Master Plan. https://static.spokanecity.org/documents/publicworks/water/water-conservation-master-plan-2020-04-27.pdf

DeOreo, W. B., Mayer, P., Dziegielewski, B., & Kiefer, J. (2016, April). Residential end uses of water, version 2 (executive report). Water Research Foundation. https://www.circleofblue.org/wp-content/uploads/2016/04/WRF_REU2016.pdf

Dieter, C. A., Linsey, K. S., Caldwell, R. R., Harris, M. A., Ivahnenko, T. I., Lovelace, J. K., Maupin, M. A., & Barber, N. L. (2018). Estimated Use of Water in the United States County-Level Data for 2015 (version 2.0). U.S. Geological Survey. https://doi.org/10.5066/F7TB15V5

Porcello, J., Burt, W., Gorski, J., & Wick, T. (2017, December 15). Climate change & summer streamflows. The Water Report (166), 1-13. https://www.spokaneaquifer.org/wp-content/uploads/2018/01/The-Water-Report-Climate-change-and-Summer-Streamflows166.12.15.17pdf.pdf

Spokane Aquifer Joint Board. (2015). The Spokane Valley-Rathdrum Prairie Aquifer Atlas. https://www.spokaneaquifer.org/2015-aquifer-atlas/mobile/

United States Geological Survey. (2018, June). Summary of estimated water use in the United States in 2015. https://pubs.usgs.gov/fs/2018/3035/fs20183035.pdf