The County has not developed a mitigation program, but they do provide a laundry list of steps are are normally required as essential parts of a mitigation program.
The County proposes replacing riparian and other valuable habitat on a 1:1 basin, but most mitigation programs requires significantly higher ratios, on the order of 3:1 to 5:1. While the County promises to perform as much of the mitigation on-site in Hahamongna, there is no way that they can do that since their program will have such extensive negative impacts on habitat in the Hahamongna basin, destroying more than one hundred acres of riparian and prime habitat.
Unmitigatable Impacts: The County states that there will be at least 3 impacts that cannot be fully mitigated: 1) air quality, 2) aesthetics and 3) traffic, although in each of these areas they fail to take reasonable steps that would reduce the detrimental impacts. Flood Control officials intend to ask County Supervisors to pass a "statement of overriding considerations" that would allow them to shirk their responsiblity to mitigate negative impacts.
Of course, when developers or agencies like LA County Flood Control District fail to take care of the negative effects of their projects, the burden is simply passed on to local neighors and the general public, who are uncompensated.