Beyond PFMs Incorporating Environmental and Economic Risk into Screening Level Risk Analysis

摘要

Colorado Parks and Wildlife (CPW) owns and operates over 110 dams, the largest inventory of dams for any owner in the State of Colorado; 34 of these dams are classified as significant and high hazard. With the number and varied condition of dams, coupled with limited funds for capital and maintenance of the aging portfolio, CPW required methodology to: 1. Identify dams which may pose the largest risk 2. Develop a capital improvement plan for funding improvements 3. Honor the CPW's Dam Safety Mission to "Prevent loss of life and property damage, manage reservoirs to enhance the wildlife resources of the state and provide enjoyable and sustainable outdoor recreational opportunities ", and 4. Prioritize actions with the acknowledgement that capital and personnel resources are limited. In order to meet these objectives, the CPW embarked upon a Screening Level Risk Analysis (SLRA) for the high and significant hazard dams; this assessment was completed in late 2013. Subsequent to this exercise, CPW decided to include the evaluation of environmental and economic/recreational factors that would be affected downstream of each dam should it fail. A decision model was built using three major criteria: 1). potential failure modes and life loss from the SLRA; 2). environmental (with sub-criteria of aquatic/terrestrial biology, cultural resources), and 3). economic/recreational factors (sub-criteria include essential facilities, damage to structures, downstream road impacts, fish replacement costs, water rights, park revenue and fishing recreation days). Using this quantitative and qualitative data, each criteria category was given a weight by CPW staff based on its importance. Using the decision model, a number of facilitated sessions took place with CPW engineers, aquatic and terrestrial biologists, ornithologists, economists, archaeologists, hydrologists, attorneys, agency leaders and dam safety regulators to ascertain the overall appropriate ranking of the criteria and priority of dam improvements. In doing this, the agency is able to execute and prioritize dam rehabilitation, refurbishment and repair with an eye not just toward public health and safety, but also for the economic, environmental and recreational import derived from these facilities.