Floods and Urban Landscapes

I spent some time yesterday reviewing urban growth areas (UGAs). UGAs are how our current local governments decide where future urban ares will be located. Under the Washington State Growth Management Act passed in the early 1990s most cities and counties need to plan for future growth. The proposed growth areas I was looking at are located adjacent to Ferndale, Nooksack and Sumas, Washington all in Whatcom County where I live.
The typical way the UGA planning works is that the County establishes an overall growth plan and must approve the city UGA plans. State Growth Boards have been set up for purposes of reviewing plans when disagreements take place. Ferndale, Nooksack and Sumas all appealed the County plans and the County Council is now considering ways to get past those disagreements with Ferndale, Nooksack and Sumas without the Hearings Board involvement. I should add that Blaine also appealed as did a large property owner north of Bellingham that wanted Bellingham's UGA to be increased and some property owners to the south of Bellingham that were displeased that Bellingham's UGA was made smaller in that area.
Some readers of this blog are well aware of my opinions on local UGA boundaries. While I do have opinions regarding growth plans and UGAs, the purpose of this blog is to try to bring an understanding of Washington State landscapes. Urban areas and why they are located where they area are part of our landscape in Washington State. So I will try to stay neutral here and keep in mind the goal of informing readers about how land use policies at the local level can shape how our Washington State landscapes appear.
Ideally growth areas will be efficient for development and minimize costs to tax payers and utility rate payers. For example, having urban areas in very hilly areas with lots of hard rock may be costly for building roads, water lines and sewer. But flat well drained land might mean loss of farm land. And poorly drained land in much of western Washington likely means wetlands or storm water challenges.
In the case of Ferndale, the current city leaders are fairly bullish on growth. But even then the City's growth boundaries are bigger then the State law allowed as the law limits growth plans to accommodate 30 years of reasonably projected growth. This created a dilemma of what areas to take out of Ferndale's UGAs. Ferndale leaders have attempted to minimize the UGA area loss with a variety of arguments and are attempting to get the County Council to put some areas removed back in.  
Sumas and Nooksack are very small towns that want some growth as well, but they face some tough dilemmas. Both towns are nearly surrounded by high quality agricultural land and abut flood areas. The Sumas River flows through both communities. The Sumas River is a small river, but the land around it is very flat and when the Nooksack River has big floods flood waters from the Nooksack flow into the Sumas Valley flooding large areas. At one time the Nooksack likely once flowed through the Sumas Valley and discharged into the Fraser River in British Columbia instead of its current route to Bellingham Bay. Paul Pitman and others have postulated that the Sumas River meander loops are too big for its small size and that the Sumas is simply following the old river channel the Nooksack used to follow to the Fraser Valley. It has been postulated that the change of flow on the Nooksack took place within the last 500 years.

  
But a more recent problem has developed on the Sumas River. Swift Creek a tributary stream is filling with sediment from a massive landslide on the west side of Sumas Mountain. This sediment load is causing the Sumas River to fill in as well. Approximately 150,000 cubic yards of sediment is entering Swift Creek every year from the slide and this is expected to continue for the next 350 years. The answer in the past has been to dredge the stream and river, but there are two problems with this approach: 1) the amount sediment entering the system is much greater than in the past as the slide and its impact to Swift Creek is a relatively new phenomenon and 2) the sediment contains asbestos in quantities that the EPA considers unsafe. Part of Nooksack's UGA request is along the banks of the Sumas River a short distance downstream of the confluence with Swift Creek.

The Swift Creek landslide is a fascinatingly complex geology, health and community problem. With the proposed Nooksack UGA it gets even more complicated.
The proposed Sumas and Nooksack urban growth areas provide insight into how flood areas become urbanized.