Protecting and Restoring Dynamic Riverine Ecosystems: A Case Study from Southern California
Bruce Orr1
1 Stillwater Sciences, Berkeley, California; bruce@stillwatersci.com
One current theme in river and riparian restoration, mitigation, and conservation planning is protecting or restoring more resilient and sustainable river-riparian ecosystems that will maintain most of their natural ecological processes and dynamics well into the future, even with increasing threats posed by climate change, human use of surface and ground waters, and altered land use. Process-based restoration has much to offer, but it also requires willingness to accept some uncertainty in the exact spatial and temporal configuration of desired habitat conditions. Instead of trying to force systems towards a single static desired condition, as has been the focus in most past restoration projects, the goal needs to be focused on taking actions to put the system on a trajectory towards a desired range of conditions such as a shifting mosaic of a diversity of native riparian and aquatic habits to support both common and rare native plants and animals. Implementing this approach poses a variety of challenges, both in our scientific understanding of how to design such systems to achieve our goals and in the regulatory and economic context of how to permit, assess, monitor, manage, and pay for such projects. In this presentation, I will discuss how our understanding of river-riparian dynamics under both current and historical conditions has helped set the stage for development and implementation of more informed restoration and mitigation projects in one of the most dynamic river systems remaining in Southern California, and some of the regulatory challenges posed by trying to develop a mitigation bank and environmental crediting approach that builds on and allows for natural river processes and a shifting mosaic of habitat conditions.