Drinking Water Utility 2026 Water Management Plan during the Upcoming Water Supply System Outage

The Salmon Creek (SC) Dam and Reservoir is owned and operated by the Alaska Electric Light & Power Co. (AEL&P) and provides ~1/3 of the source water for the City and Borough of Juneau’s (CBJ) to maintain the primary essential services of potable water distribution and community-wide fire suppression capacity.

Water is conveyed from the SC dam through a penstock ~ 3 miles to down slope to an AEL&P power production facility and discharged into a tailrace that then provides source water for both the CBJ SC water filtration plant and the Douglas Island Pink and Chum, Inc. (DIPAC) hatchery facility.

Commencing April 1, 2026, AEL&P will be replacing and upgrading the antiquated upper penstock section of the existing SC Dam and Reservoir conveyance system.  This activity will require water flow from the reservoir to be suspended while sections of the penstock are removed and replaced.  The construction phase of this program will take a total of 12 months and is scheduled to occur for three consecutive months (April 1 – June 30) starting in 2026 and to be conducted each year for four consecutive years (2026 – 2029).

During the time periods when the water flow from the SC Reservoir is restricted for construction activity, the CBJ will need to maintain potable water and fire suppression services through the use a single water supply located proximal to downtown Juneau.  The loss of the SC facility during the construction periods may be potentially consequential, since the SC facility provides a critical backup to the primary source water supply, is important in maintaining both volume and pressure to the northwest sections of the CBJ (Lemon Creek, Mendenhall Valley, Auke Lake, Lena) and aids in balancing the whole water system flow and pressure to the entirety of the CBJ.

To compensate for the temporary loss of the SC water supply and assure that the community maintains essential potable water services, the CBJ will need to take mitigative measures, including steps to reduce non-essential water demand.  These may include but are not limited to:

1. Suspension of water usage from hydrants west/northwest of the CBJ Salmon Creek facility for road maintenance, construction, fire suppression training and all other non-essential activities (see figure).
2. Discretionary reduction of water services for industrial consumers.
3. Suspension of water supply services to commercial cruise ships and other transient ships and vessels during the source water outage periods.

CBJ has also reached out to potentially affected parties.

In response to this matter, the CBJ is also in the process of:

1. Enhancing and protecting the resilience and reliability of the water production and distribution systems,
2. Assuring appropriate Utility staffing and external contractor support for rapid incident response and recovery, and
3. Developing contingency and communications plans in the event of system disruptions.

The ability of the CBJ to maintain essential water services during the AEL&P SC outage periods will depend upon climate, fire activity, system performance and various other factors, most of which are unpredictable.  However, we anticipate that through a combination of conservative use of water during these periods and enhanced preparedness, the Utility will be able to maintain our community’s essential water services.