Crescent City

Thus far I've only hinted at the series of projects that have consumed the last few years. It's time to provide some detail. These are traditional mitigation projects, in the sense that they were required to offset impacts related to a form of infrastructure development... in this case, congressionally mandated improvements to runway safety areas at Crescent City Airport. In this post, I'll briefly describe the impact side of the project. In subsequent posts I'll discuss the series of mitigation efforts, six of them in total. Cumulatively, they aren't the biggest I've done, although they are perhaps the most complex.

Crescent City is in the extreme northwest corner of California, right on the coast. The city and the airport are on a narrow and relatively flat coastal shelf, with the Siskiyou Mountains looming to the east. It's just over 20 miles to the Oregon border. Del Norte County is unique in California, more rain than most places, a temperate rain forest along the coast with Sitka spruce, shore pine, and redwood grading into the diverse mixed conifer forests and serpentine grasslands of the mountains.

Runway Safety Areas are those flat extensions off the ends and sides of runways, places for a plane to safely come to a stop in the event of an overshoot. In this case, to meet the new federal requirements and maintain commercial air service, the RSAs needed to be expanded considerably, resulting in about 17 acres of wetland fill. The work took place in the summer/fall of 2014 and 2015, meeting the congressional deadline with a couple of months to spare. We had a frequent biological monitor presence on the airport during construction.

Federal mitigation requirements were fairly standard and simple, a basic 2:1 ratio for three-parameter wetlands. The airport is in the coastal zone though, and California Coastal Commission generally requires a higher mitigation ratio. The means of determining credit is far too complex to explain here (unnecessarily complex, in my opinion), suffice it to say that I had a nine-page spreadsheet that was used to do the calculations to say nothing of the endless negotiation meetings. The end result was that we needed about 59 acres of mitigation, much of it for wetlands but also some for sensitive upland communities regulated by the state.

I'll run through each location in the next few posts: Four smaller sites on or adjacent to the airport, and two larger off-site areas. Work on those sites overlapped with the RSA construction, and was completed about a year later, in December 2016. We spent two or three years on design and permits, three years on construction, and we are now in the early part of five years of annual post-construction monitoring.

Photo: Graded  and revegetated runway safety area (RSA), about a year after construction.