Life-Cycle Cost of Urban Stream Restoration Alternatives

In this study, cost drivers of urban stream restoration practices are evaluated by performing life-cycle cost analyses on common restoration actions. The study’s objective is to examine the relative contributions of capital and operations and maintenance (O&M) costs to life-cycle costs over a range of restoration actions and sizes. Ultimately, this study will inform restoration practitioners of the importance of accounting for O&M expenses and help weigh the relative merits of different management actions. Capital and O&M costs were compiled from literature for typical urban stream restoration actions, such as bank stabilization, channel rehabilitation, and riparian restoration. Both costs were normalized by project extent to estimate typical ranges of unit costs and the frequency of actions. Representative costs were then estimated for a hypothetical project size range, life span, and other factors. Although capital costs are often a primary decision factor to select restoration actions, O&M costs are often underemphasized. This study showed that O&M expenses could rival capital costs in some contexts and that complete life-cycle cost analysis is crucial to decision-making about the long-term efficacy of urban stream management actions.