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. . . Figure 5. Re-establlsh- ment of Indige- nous and intro- duced plants three months after fire Figure 4. Flooding and mudflows following first rain- storm, Laguna Beach, November 1993 538 JOURNAL OF SOIL AND WATER CONSERVATION menta hIe process wherein the effort is phased to allow [he highest hazard areas to be identified and addressed first, followed by the: next most urgent hazard areas. During and immediately following the fires, available informadon was gathered and re- vi~ed for identification of potential haz.ards. This information included storm drain maps, topographic maps, geologic maps, hydtologic information, and aerial photographs. Both aeri- al and ground site reconnaissances were: per- formed with cwo-person field teams to assess the damage and ga.ther information on the po- tential haz.ards caused by the fire, including mud flows, debris flows. high sediment loads; flooding; rockfalls; retaining structure damage; and landslides. Based on the gathered information, the po- tential for post-fire hazards was evaluated and tabulated for various sites within the burned areas. Next, the impacts of those potential haz~ ards were evaluated. Impacts of the pon-fire hazards included public health and safety; pub- lic and private property damage; damage to in- frastructure (such as the storm drain system); transportation route damage {such as key artery loss}; or damage to receiving waters. Based on an assessment of the likelihood of the hazard wgc:ther with the severity of its impact, an over~ all judgment was made as w which sites, if any, should have the highest priority for mitigation. This evaluation was a particularly valuable tool for allocating resources. An example of a hazard assessment matrix is presented in Table 2. In both the Oakland and Southern Califor- nia fires, this technique was used, and resulted in mitigation efforts being focused on those hazards that would have a high impact on pub- lic health and safety, public and private proper- ty damage, infrastructure damage, transporta- tion route damage, and damage to receiving waters. In all cases, these hazards occurred at the urban interface areas. Where mere were po~ tential hazards with a medium or high likeli- hood of occurring, but the potential impacts were low, then no mitigation of the hazards was recommended or implemented. Typically, this occurred in the more open, undeveloped areas. Development of plans The first step in mitigating the identified high priority post-fire hazards was to develop Early Action Plans that provided for immediate sediment control to reduce the impact of flood- ing and mudflows on developed areas. Early ac- tion measures should be identified to imple- ment immediately if rains are imminent. Both the Oakland and Southern California fires oc- curred in late October at the start of the rainy season, and in both cases, Early Action Plans were prepared and being implemented within a week of the fites being put out. These early ac- tion measures were intended to provide as