Courtesy photos
FLAGSTAFF — In Flagstaff, our water supplies are integrally linked to forest conditions. Healthy forests support healthy watersheds and allow our reservoir and aquifers to be “recharged” through rainfall and snowmelt.
The City’s Utilities Division understands the importance of the forest–watershed nexus; it has been responsible for quantifying and forecasting water supplies for more than 100 years. Through careful planning and sound management, the Utilities Division has ensured that Flagstaff’s water supplies will last well into the future. However, planning and management require scientific data.
“That’s where a new partnership with the Salt River Project and its state-of-the-art SRP Flowtography® system comes into play,” said Flagstaff City Water Resources Manager Erin Young. “As part of a contract approved earlier this year by the City Council, SRP will monitor and analyze streamflow as part of the Upper Lake Mary Watershed Monitoring Project for many years.”
The largest provider of raw water to the Phoenix metropolitan area, SRP developed the Flowtography® system as a simple, inexpensive way of monitoring stream flow. The technology uses both time-lapse cameras and instream visual staff gauges to document stream flow, snow accumulation, and overall watershed conditions. This new tool has proven valuable to SRP, which captures and manages water that falls on 13,000 square miles of the Salt and Verde River watersheds for use in the Salt River Valley.
Brad Hill, Flagstaff City Utilities Director, supports the monitoring plan. “It is significant that the City and SRP are collaborating to measure the Upper Lake Mary watershed. SRP has been a leader in this type of hydrologic monitoring across northern Arizona for over a century. By partnering with SRP, we’re demonstrating our commitment and long-term stewardship of the watershed to the benefit of all Flagstaff water customers.”
This monitoring effort is important because it will provide data that the Utilities Division can use to “calibrate” its watershed model — a key tool for forecasting water supplies — to real-life conditions.
The suppression of forest fires and other influencing factors over the last 100 years has left northern Arizona’s forests choked with trees. As seen in Arizona and across the western U.S., these fires burn far more acres than in the past, at temperatures that are so hot they demolish entire forests, essentially turning the forest floor into concrete — a problem that is compounded when heavy monsoon storms later pound the landscape.
Several local initiatives are attempting to restore natural or “pre-settlement” forest conditions by making physical changes to the watershed. One is the Flagstaff Watershed Protection Project, which voters overwhelmingly approved after the Schultz Fire in 2010. Two others are the efforts of the Greater Flagstaff Forests Partnership (GFFP) and the Four Forest Restoration Initiative (4FRI).
“The immediate objectives of these initiatives,” Young said, “is not necessarily the same as ours – maximizing water supply – but by managing the forest to reduce tree density and wildfire damage, all contribute to ensuring we have a clean and reliable supply of water. We are interested in forest treatment and maintenance practices that promote conditions for aquifer recharge, surface runoff to the reservoir, and the maintenance of natural spring flows. Documenting conditions until we’ve got enough information to calibrate a watershed model will be essential to understanding the various forest conditions that benefit water supply.”
Traditional methods such as a streamflow gauge provide great information. However, Young said, without photographic documentation, it’s often hard to know if some of the data points we see are anomalous. SRP’s Flowtography®technology helps to answer these questions by providing a photo as evidence.
The benefit of working with SRP is that it will provide equipment, servicing, and image processing of the photos for Flagstaff. Much of this information will be available to the public.
Flagstaff is already benefiting from this partnership with SRP. In the first month of Flowtography® use, nearly 600 images have been collected daily from locations across the Upper Lake Mary Watershed. These images have been sifted through by sophisticated photo processing software, quality checked by staff, and used to report runoff events to the City.
Other organizations involved in the monitoring program include Northern Arizona University, the U.S. Forest Service’s Rocky Mountain Research Station, Flagstaff Watershed Protection Project, National Park Service, and the U.S. Geological Survey.
For more information visit www.flagstaff.az.gov/lakemarywatershed or contact SRP Media Relations Representative, Jeff Lane, at 602-236-2500 or jeff.lane@srpnet.com and City of Flagstaff Water Resource Manager, Erin Young, at 928-213-2405 or eyoung@flagstaffaz.gov.