Washoe County Commission Meeting to include decisions on flood mitigation & lowering water levels in Swan Lake

Top things to know ahead of the meeting

Reno, Nev. Aug. 26, 2019. The Washoe County Commission will hold a meeting tomorrow, August 27, 2019 at 10:00 a.m. in Commission Chambers. A presentation on the North Valleys Closed Hydrobasins will be given and action items for consideration will include flood mitigation efforts to prepare for the upcoming winter and plans for water removal in Swan Lake.

PURPOSE: The action item for consideration will appropriate $2.5 million to reduce storm and floodwater impacts and remove water from Swan Lake. If authorized, these funds can be used to:

• Continue operation and maintenance of existing barrier and pumping systems
• Fund potential enhancements should the area experience wet winter and spring events
• Pay for future land application and aeration systems which will remove water
• Begin feasibility studies for long-term options

MEETING ACTION ITEM: AUTHORIZE $2.5 MILLION TO MANAGE LAKE WATERS, INITIATE WATER REMOVAL AND UNDERSTAND FEASIBILITY OF LONG-TERM OPTIONS

Currently, the existing barrier systems safely provides substantial protections, however it is recognized that additional protection efforts would likely be required should lake levels rise an additional four feet. Precipitation events cannot be predicted or stopped, however Washoe County staff will present options to reduce the volume as a proactive step to make room for future flood and stormwater. Options include:

• Land application has been identified as a short-term project to enhance the natural evaporative process. Staff is collaboratively working with the owners of private properties located on the east side of Swan Lake to allow for the placement of pumps, piping and traditional irrigation sprinkler heads for land application over the next two to three years. This is a separate effort from the City of Reno’s “American Flat” project that Washoe County is supporting.

• Enhanced mechanical aeration of the treated effluent at Washoe County’s Lemmon Valley Water Reclamation Facility is also being developed. This will be done by further treating the effluent produced at the plant to the same irrigation water standards that are currently in place and in practice in the area. All appropriate permits will be in place prior to implementation of this project.

• Alternative pumping and barrier systems in specific areas around the lake. Based on an action plan that was developed in 2017 and updated in 2019, work around the lake will be done to improve protections when needed.  An example would be installation of a barrier system outside the Lemmon Valley School playground.

• Long-term mitigation planning efforts are also in progress. To prevent future flooding, ongoing planning and studies are currently being developed specific to closed basins. A matrix of solutions is under review and will be narrowed down to a few options. These options will undergo a review and will include input from the community and stakeholders.

BACKGROUND: Since the fall of 2016, our region has experienced record-breaking snow and rainfall particularly impacting closed hydro-basins in Lemmon Valley and Stead.

Washoe County has responded by protecting against flooding during weather events with the Commission’s directive to protect residences and lives and keep the lake within the lake. The top protections put in place and consistently maintained by Washoe County are:

• HESCO barriers: HESCO barriers are military-grade temporary flood barriers surrounding Swan Lake that were erected in January of 2017. The barriers are four-feet high, extend four-miles around the lake and filled with 12,000 yards of sand.
• Strategically located pumps: Pump stations have been placed around Swan Lake where water has collected to pump it back into the lake to keep it contained. These pumps have periodically changed locations around the lake as needed to maximize protections. These pumps are a part of the overall strategy for managing and maintaining the barrier system surrounding Swan Lake.
• Inflatable Dam: In April 2019, Washoe County crews installed additional protections in the form of temporary inflatable dams to provided added security to residents in the area.
• K-Rail: K-rails are semi-permanent protections in high traffic areas. They were installed in spring of 2019 around Swan Lake to provide additional protection of the barrier system and traveling public.
• Consistent water quality testing: Washoe County staff has continually performed water quality testing of the water in Swan Lake as a protection for residents. All results have been posted to the Washoe County website, click here for water quality reports.

To watch the meeting live, visit Washoe County’s YouTube channel by clicking here.

###