Finn Hill Residents Query Experts on Landslides at Neighborhood Meeting

UW’s Kathy Troost keynotes, with a panel including city officials, a local biologist, and a geotech engineer.

Three months after the terrible mudslide tragedy in Oso, WA. the Finn Hill Neighborhood Alliance held a first-ever special event exploring the threats of landslides and mudslides in our corner of Kirkland and Kenmore.

Held as part of FHNA’s general meeting, June 25th, 2014, the event attracted more than 125 residents and concerned homeowners, many interested in learning to identify and reduce risks of erosion or slippage on properties where they live.

Kathy Goetz Troost, a senior lecturer at the University of Washington’s Department of Earth and Applied Sciences, delivered the keynote talk. One of the foremost experts in Puget Sound lowland geology, she addressed landslide risks on Finn Hill and Goat Hill, detailing what landslides are and why they predominate here where we live, in the Puget Sound.

While it may come as a shock to some of us to learn this, the hills that we live on – Finn Hill and Goat Hill – are particularly prone to landslides and mudslides. “They not only appear on King County’s hazard maps, but a good portion of our neighborhood is in a high hazard area,” said FHNA board member Francesca Lyman, organizer of the event, who introduced Troost and the panelists. She noted that the Holmes Point Overlay, for the western slope of Finn Hill, which rises to an elevation of 500 feet, was designed to particularly take into consideration steep and hazardous slopes.

Troost reassured the audience that she was not finding evidence of imminent risks but added that assessing landslide risks on our very steep slopes was extremely important. “This isn’t some pointy-headed academic exercise but has real meaning here.”

 

Finn Hill June 2014 Neighborhood Meeting

Finn Hill June 2014 Neighborhood Meeting

Residents clamored to ask questions of a panel of five experts during a nearly hour-long question-and-answer session. Among the panelists addressing landslides and erosion in various ways—were two Kirkland city officials, Jenny Gaus, surface water engineer in the Department of Public Works, and Nancy Cox, development review director in the Department of Planning. Also speaking were geotechnical engineer Charles Couvrette of Robinson Noble Engineering, and local biologist Louis Berner, former board member of FHNA and author of a report on surface water concerns affecting Finn Hill.

Troost presented a custom-made series of maps, scanning the Finn Hill area under LIDAR, a remote sensing technology that measures altitude and distance, to illuminate Finn Hill’s unique topography, its signs of ancient slides and unique slopes. She revealed where, close the shores of O.O. Denny Park, a sunken forest still lies, remnants of one of those ancient landslides.

A landslide approaching the scale of Oso may have occurred 1,000 years ago, with Seattle’s massive earthquakes at the time, Troost told the group.  Troost cautioned, however, that while the possibility of slides of this magnitude are highly remote, it’s important to face the fact that our homes sit on highly hazardous landslide prone slopes.

“Given all that we’ve learned since the terrible wreckage and tragedy of Oso, we at the Finn Hill Neighborhood Alliance thought it would be a good idea to really take a look at the topography of where we live, so we can better understand the hazards we may face and know how to prevent further risk,” said Lyman. “We don’t want to overplay the hazards here but we don’t want to underestimate them either.”

The panel of professionals brought together included the following experts (bios attached) who have given a lot of time to this issue.

The meeting is just the first in what will probably be a series helping to educate the public on what the city of Kirkland is doing to prevent landslides.

“Even in recent years, mudslides have closed roads and endangered homes, property, and lives,” as FHNA’s press release stated, [reprinted here by Kirkland Views]

“While a slide on the scale of Oso is highly remote, many homes here are built adjacent to ravines, inclines and steep slopes, where slides are possible,” said Finn Hill Neighborhood Alliance President Scott Morris. “What do we know about our landslide geology history? What do homeowners need to know?”

A video tape of the meeting is being produced and edited for podcasting on our website.

Panelists at the Landslide Event

Kathy Goetz Troost is a Washington-State licensed geologist with 34 years’ experience conducting in-depth geologic studies. A lecturer on the faculty of the University of Washington, in the Department of Earth and Space Sciences, she’s considered one the leading experts in Puget Lowland geology. Kathy has worked extensively along the Puget Sound coastline, mapping landslides, landforms, and geology in urban and coastal areas, including such cities as Mercer Island, Bothell, Kirkland, and Seattle.

All of the geological maps that she has authored or co-authored have included steep slopes and/or coastal bluffs where landsliding is prevalent. Besides making high-resolution geological and hazard maps, Kathy has also served as a liaison between consultants, research scientists, and decision makers. She completed her Masters and PhD Degree in Geology at the UW in Seattle.

Nancy Cox is the Development Review Manager for the Planning Department in the City of Kirkland. In her position, she oversees permitting for the Planning Department and administration of the Kirkland Zoning Code. She is a planner belonging to the American Institute of Certified Planners and will speak to us about the relevant city codes that apply to steep slopes and landslide risks.

Lou Berner, a native of Seattle’s Eastside has lived on Finn Hill since 2001. He is a biologist who has worked on a variety of green space and habitat issues, and now serves as a point of contact between Finn Hill residents and the city of Kirkland. He’s helped out on various civic issues, everything from the recent Holmes Point Overlay revision to significant trees determinations to dead goats in our creeks.

Charles P. Couvrette, is Principal Geotechnical engineer for Robinson Noble engineers, in Woodinville and Tacoma. He has been practicing geotech engineering mainly in the greater Puget Sound region, since 1978. He has consulted on the design and construction of residential, commercial and industrial projects, such as warehouse facilities, many of which required construction over soft ground and thus require appropriate support. He’s also worked as a consultant on storm water and slope stability projects and has been relied upon by the insurance industry for the forensic evaluation of geotechnical-related damages to structures and hillsides.

Jenny Gaus has worked on surface water management for the City of Kirkland since 1998. With a background in civil engineering and forestry, she did her master’s thesis on soils in infiltration ponds. Her main project at the moment is update of the City’s Surface Water Master Plan which will chart the course for the next 5 to 10 years’ operation of the Surface Water Utility. The current surface water management practices call for extensive use of infiltration of storm water, but there may be instances where this practice is at odds with the need to reduce landslide risk.

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