River Flow

By over-allocating water rights, Washington is ruining many of our rivers, mining aquifers that will undermine economies, and setting in motion water conflict and water crisis.¹

Change in river flow directly impacts the Spokane River's health, and is affected by natural and human causes. Quantity and quality of river water are inextricably linked. You've probably heard the saying that "dilution is the solution to pollution." Contaminants come from everyday behavior in the city, industrial use, plus pesticides and fertilizers from agriculture.

Low flows typically aggravate the effects of water pollution. During a low flow event, there is less water available to dilute effluent loadings, resulting in higher in-stream concentration of pollutants and low amounts of dissolved oxygen.²

Low flow is harmful to humans as well. We depend on rivers as a major water and energy source. Sapping the strength of our river is detrimental to the local economy by harming recreation and tourism, because rafting, fishing, floating and other activities are not possible. Over the past 100 years, the lowest flow of the season has been trending lower year by year.

What will be measured and how?

First, it reflects water conservation of those who draw from the Spokane River. More conservation means a higher flow and a healthier river. Currently, the City of Spokane is the biggest pumper from the river, although it is only using half of its water rights. The full use of these water rights could mean even more devastation to an already dangerously low flow in the summer.

Second, flow reflects precipitation and snow pack. The warming climate means that the yearly snow pack will be getting smaller, and therefore there will be less snow melt in the summers, and a lower flow in the river. The Spokane Gauge, which is downstream from the Upriver Dam, is constantly measuring the river flow by cubic feet per second.

It is measured using the Environmental Protection Agency's hydrologically-based design flow method, developed by the U.S. Geological Survey3. This "is computed using the single lowest flow event from each year of record and then examining these flows for a series of years." Next, this data is considered using the "7Q10" strategy, which "is the lowest 7-day average flow that occurs (on average) once every 10 years"⁴.

Where are we now?

In 2008, the lowest flow of the Spokane River was below 881 cubic feet per second⁵. Any time the river flow is beneath 1,000 cubic feet per second, the river is at its worst for the risks mentioned above.

What can I do?

Conserve water! 

• Smart Watering: "The average person in Spokane County used 217 gallons of water per day in the year 2000. The Washington State average is 114 gallons per day (USGS 2004). According to officials from the Department of Ecology and the Spokane Aquifer Joint Board, almost all of the difference is in landscape watering.
• The Department of Ecology reports that a 10% reduction in summer withdrawals from the aquifer would increase flow by 40cfs or approximately 5% of August river flow"⁶. We use a great deal of water on our lawns. In the summer, water use triples in Spokane. "Experts estimate that 50% or more of this water goes to waste, due to evaporation, runoff, or simply overwatering"⁷.
• Water depending on the type of plant, make every drop count by watering early in the day or late at night, use drip irrigation, plant drought-tolerant plants, and water deeply, but less often. For details on these tips and others, visit: Smart Watering
• Purchase an irrigation controller for watering your lawn. For more information, visit: Irrigation Controller
• In the bathroom, laundry room, and kitchen: "Use shower heads that flow at 2.5 gallons per minute (gpm) or less," install an efficient toilet, clothes washer and dishwasher, turn off the water when shaving or brushing your teeth, take short showers, only wash full loads, and check for and fix leaks regularly⁸.

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1.) "Water Vision for the Future" Center For Environmental Law and Policy
2.) "Flow 101: A Tool for Low Flow Analysis" US EPA 
3.) "USGS 12422500 Spokane River at Spokane, WA" US Department of the Interior, US   Geological Survey.
4.) "Flow 101: A Tool for Low Flow Analysis" US EPA
5.) "Water Data Report 2008 12422500 Spokane River at Spokane WA" US Geological Survey: Science for a Changing World.
6.) "Water Conservation" County Division of Utilities: Water Resources.
7.) "Smart Watering" The Natural Lawn and Garden; Healthy Landscapes for a Healthy Environment
8.) "Conserve Inside" Saving Water Partnership: Seattle and Participating Local Water Utilities.