SLVWD Board Meeting Summary
October 21, 2020
Mark Dolson
New Business
Landslide and Debris Flow Hazard Conditions
This was a special meeting intended to update the Board and the public on ongoing preparations for the approaching winter rains and to solicit related questions and comments. District Manager Rick Rogers read a four-page memo summarizing the relevant findings of (and the District’s evolving response to) a recent report, “Watershed Emergency Response Team Evaluation: CZU LIGHTNING COMPLEX,” produced by CALFIRE and the California Department of Conservation and received by the District 10/12. Rick emphasized that the report’s findings are only preliminary and that meetings and assessments are continuing to occur.
The goal of the report is to assist communities and relevant agencies in planning. It includes a number of recommendations for the Highway 9 corridor which can be broadly summarized as:
Educate the public about the mechanics and likely locations of post-fire debris flows.
Establish early-warning systems and implement precautionary evacuations.
Perform storm patrols and remove debris from channels.
Evaluate the potential for installing storm water control and deflection structures.
Rick called particular attention to a finding on page 40 of the WERT report noting that there was potential for a debris flow to overflow the Harmon Creek channel immediately upslope of Boulder Creek Elementary School and the adjoining neighborhood. The report recommended further observations by a certified Professional Geologist and Professional Engineer to determine whether some sort of deflection structure might lessen this danger.
Rick said the County could potentially help facilitate a design and seek funding for a deflection structure, as this would be far beyond the District’s resources. A meeting is planned for 10/27 with the District, the CalOES (Office of Emergency Services) Watershed Task Force, and Supervisor McPherson to further discuss this. At the same time, Rick cautioned that: (a) there is currently insufficient information to begin discussing the logistics of any such potential undertaking, and (b) experienced geologists are uniformly pessimistic about the viability of such a project.
The remaining hour and fifteen minutes of the meeting was given over to a wide-ranging discussion of various debris-flow related questions, ideas, and concerns with all five Directors participating. The bottom line can be roughly summarized as follows: The District owns about 1600 acres on Ben Lomond Mountain. Fire damage to this property has introduced two novel threats for the coming winter: (1) District infrastructure could be damaged by debris flows, and (2) downslope residents and residences could be harmed by debris flows originating on District property. The Board basically just needs to know what the District can feasibly do about each of these two threats and what specific related decisions the District needs to make.
For the first threat, Rick Rogers said the focus is on the treatment plant; erosion control and infrastructure hardening are being implemented (including the use of K-rails, the temporary concrete barriers often seen on highways). Assuming that the Board supports this initiative, there are no pending decisions on this front.
For the second threat, there was a lot of discussion about what the District might conceivably do or might ideally do (and about what the District might potentially be sued for doing or not doing), but most of this discussion was highly speculative or purely hypothetical. Everyone agreed that the top goal would be to avoid any loss of life and that it would be desirable to also minimize loss of property if possible. Evacuation (particularly in tandem with an effective prediction and public engagement capability) is the only currently identified strategy for saving lives. In contrast, there is currently no known construction project that the District could undertake to substantially reduce the risk of property loss due to debris flow. The District should certainly continue to support an effective evacuation strategy, and it should certainly remain open to the (remote) possibility of an effective diversion strategy, but there are no currently identified decisions that the Board needs to make.
Director Farris suggested that, in addition to the Environmental Committee scheduled for 10/22 and the Budget and Finance Committee meeting scheduled for next week, it would be good to reconvene the Engineering Committee. Rick Rogers agreed to discuss this further but cautioned that staff is already working extremely long hours and contending with a great many meetings.
President Swan questioned whether the County has a really comprehensive education plan that it is ready to execute on. Rick Rogers responded that he expects the county to soon put out quite a bit of information. He said the District is looking for help from the county in getting to the people at CalOES and the federal government in order to determine next steps – the WERT report has a lot of information but not enough to move ahead. In addition, conversations with Bruce McPherson have been frequent and productive, and the Director of Public Works is also very engaged. Valley fire chiefs are working closely with the county as well. Rick said everyone is working as a team.
Director Fultz expressed repeated concern about failing to protect the property of residents or, at a minimum, failing to adequately educate residents about the potential for property loss (and their likely lack of insurance coverage).
Comments from the public (particularly a civil engineer and two geologists) tended to emphasize the inadequacy (and unpredictability) of diversion structures in the face of a substantial debris flow.
There was general agreement that the District should continue to learn more about its options and that the Board should meet again soon after the 10/27 CalOES meeting.