Agenda - Environmental Policy Board - 11/02/2009

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CITY OF ROCHESTER, MN Emerald Ash Borer Management Plan Purpose: By implementing the provisions in this management plan, the City will take a proactive approach and attempt to spread the costs associated with the outbreak of Emerald Ash Borer over ten to fifteen years. The loss of most every ash tree in Rochester will have a devastating effect on home values, quality of life and the environment. Our goal is to buffer that impact in advance by implementing current arboricultural management activities. Introduction: Emerald Ash Borer (EAB) is an introduced pest that is currently killing all species of ash trees (Fraxinus sp) in thirteen states and two Canadian provinces. Since its discovery in Detroit, Michigan in 2002, the insect has spread killing all the ash trees in its path. The City of Rochester must prepare and manage for the arrival ofEAB on three fronts - street trees, public property (i.e. parks) and trees on private property. While no one can accurately determine when the insect will arrive in Rochester, our best estimate would be as soon as 20 I 0 from SE Minnesota / SW Wisconsin. According to the Minnesota Department of Agriculture staff - the EAB could already be here - brought here via firewood or from out of state nursery stock. As of August 2009, with the boulevard tree inventory 99% complete, we have 8,900 ash trees which represent 23.7% of our entire inventoried boulevard tree population. About 53% of all the inventoried ash are rated in good condition, 46% are rated in fair condition, and 1% in poor condition (a poor condition rating is saved for the trees that need to be removed within one year). Our best estimate for the city park lands which includes neighborhood parks, community parks, woodlands, facilities, and golf courses --.:. is approximately 25,000 trees greater than six inches in diameter over an area of 3,500 acres (+7 trees per acre). Private property estimates exceed 47,000 ash. The current evidence from Michigan and Ohio show that once EAB becomes established - it takes about five to ten years to infest and kill the majority of the ash trees in a city. The following elements of the City's EAB management plan have been recommended to the park board in 2007, and are subject to periodic revision as new information about the EAB becomes available. This plan is also subject to change should state or federal policies dictate.