Table 10 Pre-event and post-event mitigation strageties for critical infrastructure sectors in the three main urban areas affected by ashfall
Infrastructure | Towns | Pre-event planning | Mitigation | Recovery strategies |
|---|---|---|---|---|
Electricity | Villa la Angostura | Some ashfall planning, mosly around the cleaning of lines | Fire trucks deployed to wash insulators; Increased insulator pin length from 250 mm to 500 mm (initially in locations prone to flashover, but eventually all 3,500 insulators were changed) | Cleaning insulators; increase insulator pin length |
Bariloche | Some ashfall planning, mosly around the cleaning of lines | 20 MW diesel generation plant installed for back-up supply (usual demand 45–55 MW so some shortfall); fire crews rinsed insulators | Cleaning insulators; generator use | |
Jacobacci | No ashfall specific planning | Switches required ongoing replacements (for months after the eruption); volunteer firefighters washed lines after the eruption and severe remobilisation events (however due to ash remaining dry because of the lack of rainfall flashover risk was reduced) | Cleaning insulators; replacement of switches | |
Water Supply | Villa la Angostura | Planning for stream blockages (army brought in to clear these) | Drilled a groundwater well ~21 m deep (not treated and distributed via gravity fed system) to make up for the short fall due to issues with stream blockages and pump maintenance issues; pumps that were abraided by ashfall were replaced | Replacement of pumps/pump components; new groundwater well drilled |
Bariloche | No ashfall specific planning | Sand filters neded to be cleaned more frequently than the pre-eruption routine which was for one sand bed out of rotation for cleaning every ten days; generators prioritised for running pumps to treatment plant, however the demand (2 MW) exceeded the capacity of the generator trucks (1 MW per truck) | Replacement of pumps/pump components; cleaning of filtration mechanisms | |
Jacobacci | No ashfall specific planning | A new well was dug to to cover the increased demand due to the eruption | New groundwater well drilled | |
Infrastructure | Towns | Pre-event planning | Mitigation | Recovery strategies |
Waste water | Villa la Angostura | No ashfall specific planning | - | - |
Bariloche | Some planning but only to itry prevent ash from getting into system initially | Some discharge of untreated wastewater was made into the lake as the system became overwhelmed; municipal crews dug ash out of catchpits to try prevent ash getting into the system; manually moved generators around the system to keep wastewater moving; pump impellers replaced every six months rather than 12 | Discharge of untreated wastewater into lake; replacement of pump components | |
Jacobacci | No ashfall specific planning | - | - | |
Roading | Villa la Angostura | Some ashfall planning but underestimated the amount of ashfall and the number of trucks required | Route 231 and the main roads within the town were cleared by bulldozers the day after the eruption; water tankers were used to dampen down ash and prevent remobilisation | Bulldozing and sweeping roads clear; dampening down ash; cleaning air filters more frequently |
Bariloche | Some ashfall planning but underestimated the amount of ashfall and the number of trucks required | Main roads began to be cleared of ash by municipal authorities within hours of eruption; road sweepers were deployed for smaller ashfall events | Bulldozing and sweeping roads clear; dampening down ash; cleaning air filters more frequently | |
Jacobacci | Some ashfall planning, but not specific amounts and equipment | Speeds reduced to 20 km/h on days where ashfall was being remobilised; municipal water trucks dampened down ash on roads; ash removal and clean up focussed on main roads and reopening link to Bariloche | Bulldozing and sweeping roads clear; dampening down ash; cleaning air filters more frequently | |
Airports | Bariloche | Some ashfall planning | Did not receive official warning so no prior actions could be taken; ashfall was placed into hollows and dips in the surrounding land and then vegetated to prevent remobilisation; an extensive irrigation system was also installed to keep ash from remobilised onto the runway | Removal of ash; dampening down of ash; permanent irrigation system installed |