Flooding has long been an issue along these lower six miles of the Tolt; many residences are at risk during even modest flood events. But also of concern is what is called channel migration, when the river changes course and cuts a new path, heedless, of course, of private property lines.
When Terry started, LiDAR – aerial imagery that uses laser to map river-basin topography – didn’t exist. Nor were GIS – Geographic Information Systems – or, for that matter, high-tech sonar-based river surveys in widespread use.
King County ecologists document species prior to river construction projects to plan for protection and relocation efforts, if necessary.
The time and energy it takes to thoroughly clean your boots and equipment on site is a small price to pay for the time, expense and heartbreak of finding and controlling a whole new site.