AGENCY DECISIONS ABOUT GROWING large blue gum eucalyptus trees may be as risky as Frank Havens’ Mahogany Eucalyptus and Land Company of the early 1900s. That enterprise ultimately went belly-up when Havens’ 3,000 acres of eucalyptus trees in the East Bay Hills failed to become a “gold mine,” proving to be unusable for hardwood lumber. One hundred years later, the East Bay Regional Park District (Park District) and other agencies could be stuck spending untold millions trying to deal with Havens’ large and dense groves, now identified as extreme wildfire hazards.
The Park District’s 2010 Wildfire Hazard Mitigation Plan and EIR (the Plan) specified that 1,200 acres of dense eucalyptus groves would be managed but failed to inform the public or the Park District board about the potential costs required to implement the Plan. Calculations show that the Park District’s eucalyptus fire hazard reduction strategy could cost well over 100 million dollars during the next 30-50 years.
The Plan recommends thinning groves to 20-30-foot spacing between trees—then following up with ongoing pruning and removal of sprouts, ribbon bark, ground fuel, and understory every 3-5 years. The Park District’s eucalyptus groves would eventually become single-age stands with bare understory until the remaining large trees begin to fail and must be removed. No one knows for sure when a tree will fail, but around 150 years of tree age is a good guess, based on structural problems and liability concerns connected with several of the older blue gum eucalyptus trees in the Bay Area.
The Plan did not offer realistic cost projections for the management of the Park District’s 1,200 acres of blue gum eucalyptus, for either thinning or ongoing maintenance, and completely omitted all costs related to the eventual removal of the 60,000 trees that will eventually fail in groves thinned to approximately 50 large trees per acre.
Blue gum eucalypts are massive trees that can be expected to exceed 150 feet in height, have five-foot diameters, and weigh over 40 tons each. Aging, gigantic blue gum eucalypts, often referred to as “widow makers,” can also become serious public safety hazards with removal costs of $1,000-$4,000 per tree. Planted trees do not live forever, so removal of large numbers of eucalyptus trees will not be a simple matter, and should not be dependent on individual tree hazard, disease, age, or condition of single trees. To be done economically, agencies responsible for management of large acreage must be able to take advantage of economy-of-scale contracts when the time comes for removal.
Apparently, cost was not a factor in determining how to deal with high risk eucalyptus groves, even though the Response to Comments section of the Park District’s Plan EIR stated that “there is widespread agreement that the conversion of eucalyptus and pine plantations to plant communities that present a lower wildfire risk and a higher concentration of native plants is an effective way to reduce fire risk.”
The conversion process from eucalyptus to native vegetation should begin as soon as possible for high-risk groves impacted by Diablo winds. Priority should be given to groves that occur along high ridges, along evacuation routes, on the leeward side of the hills above homes, and all groves that re-sprouted after the 1972 freeze. Converting to native vegetation at the earliest feasible time in these selected groves, rather than waiting until costs skyrocket in the future, will help keep agency costs lower. These priority groves deserve special attention. There will be plenty of blue gum eucalyptus acreage remaining elsewhere in the East Bay Hills for the public to enjoy.