Trials and tribulations of two-dimensional modeling for the Nooksack River, Washington

Computer modeling has been the basis for mapping floodplains for many years. Until now, most detailed floodplain maps have been based on results produced by one-dimensional steady-state computer models. New, faster computers have made it possible to develop two-dimensional models for river floodplains that give much more detailed flooding information. The purpose of developing a two-dimensional model of the lower Nooksack River was to create a better set of tools for long-term flood hazard management in Whatcom County. In the past, flooding along the river has been extremely costly. Unfortunately, regulations based on the existing floodplain mapping allow development in potentially hazardous areas

A look at the effect of floodplain management regulations on development patterns in ten northwest communities

The paper explores the sort of information needed to evaluate and back up land use management measures. It examines the effect of such measures on building patterns in 10 communities in Oregon and Washington. Not an exhaustive or scientific study, it experiments with one possible approach to a more scientific undertaking. While focusing on floodplain management, this practice study is intended to have broader implications for management and information needs relevant to other types of sensitive lands. The study uses two methods for examining regulatory impacts on development: (1) interviews with planners in 10 NFIP communities in Oregon and Washington, and (2) test comparisons of two planners interview responses with actual development patterns around floodplains in their jurisdictions (Snohomish County, Washington, and Jackson County, Oregon). The study outlines information needs and suitable criteria for distinguishing regulatory impacts