timize ecological benefits and water supply goals. They also identified the need for better information and modeling of the survival and growth of covered species and predators to establish baseline conditions against which benefits can be assessed…” (DRERIP, see Appendix F‐1 of the draft BDCP, p. 17).
This is just one example of the strong body of scientific information that is available to support specific actions within the plan. Nevertheless, there is a deficiency in the scientific synthesis that is needed to support the collective actions specified in the BDCP. Some examples of opportunities for demonstrating that scientific synthesis are described below.
The analyses for the Delta Risk Management Strategy (DRMS, 2009) have been performed to better understand the various risks to the integrity of levees and the local and statewide consequences of levee failure. Although there are limitations to this analysis, the results can offer guidance for prioritizing actions within the BDCP. For example, the DRMS study indicates that the benefits of the restorative conservation measures could be lost if levees failed and concludes that current levee management strategies in the Delta are unsustainable because of seismic risk, high water conditions, sea level rise and land subsidence. In addition to these broad conclusions, the report offers specific estimates of land impacts (e.g., economic costs of more than $15billion due to earthquake-derived levee failures and associated flooding of 20 islands)(DRMS, 2009).
California continues to invest in levee restoration, and additional restoration is included in the BDCP. However, levee repairs are not prioritized with regard to objectives such as habitat restoration, salinity management, drinking water protection, and preserving agriculture and historic Delta communities. Thus, any effects analysis should explicitly consider the interactions and tradeoffs between infrastructure and ecosystem goals. These interactions and tradeoffs may be considered in a risk-based framework, which could be complemented by analysis of the system reliability (the likelihood that a hydrosystem will fail to achieve some target), resilience (the ability of a system to accommodate, survive, and recover from unanticipated perturbation or disturbance), and vulnerability (the severity of the consequences of failure)(Fiering, 1982; Hashimoto, 1982; Moyle et al., 1986).
Furthermore, decision frameworks have recently been demonstrated in the Delta that highlight the economic tradeoffs of levee repair against the value of land and assets protected by those levees (Suddeth et al., 2010). The results suggest that, even with doubling of property values, repair of levees is not economically justifiable for most of the islands within the Delta's Primary Zone. Although decisions regarding levees, habitat, land use, and water alloca-