WS 2014 02 24
CHANHASSEN CITY COUNCIL
WORK SESSION
FEBRUARY 24, 2014
Mayor Furlong called the work session to order at 6:00 p.m.
COUNCIL MEMBERS PRESENT:
Mayor Furlong, Councilman McDonald, Councilwoman
Tjornhom, Councilwoman Ernst, and Councilman Laufenburger
STAFF PRESENT:
Todd Gerhardt, Laurie Hokkanen, Kate Aanenson, Paul Oehme, Todd Hoffman,
and Jill Sinclair
UPDATE ON EMERALD ASH BORER.
Todd Gerhardt gave an introduction to the Emerald Ash Borer discussion. Jill Sinclair shared samples of
the actual bug and larvae before giving a presentation about the Ash Borer. She explained how the ash
borer disrupts the transport of water and kills the tree. Ash trees are often partially filled out, so it can be
hard to tell which trees are affected. One tell tale sign is the presence of woodpeckers, who love to feast
on the bug. Jill gave a short history of how Emerald Ash Borer has traveled to Minnesota, where it is
confirmed in 4 counties, the closest being Hennepin County and the closest confirmed tree in Lakewood
Cemetery in Minneapolis. There are parasitic wasps that have been released and are intended to control
the Emerald Ash Borer population. All recent confirmations have been to the north and east. Luckily, it
doesn’t seem to be spreading west. Most spread has been through human movement. The insects on their
own move slowly, maybe ½ mile a year.
So, what’s the big deal? The Emerald Ash Borer is fatal to all types of ash trees. Impacts rise
exponentially once insect populations rise. Jill showed before and after pictures of streets devastated by
ash tree deaths with noticeable differences in aesthetic and environmental impacts. The stormwater
doesn’t receive as much treatment, the street gets hotter, homes can be hotter, lawns are drier and can
have impacts on real estate values. She explained that Chanhassen has three gentleman volunteers
trained through the U of MN Tree Master program who have worked to conduct a tree inventory over the
last three years. This inventory allows the City to start to implement best management practices.
How many ash trees are in Chanhassen? 20% of city right-of-way trees are Ash (1230) and 76,000 (25%)
of front yard trees. Guidelines call for no more than 20% of any type of tree so Chanhassen is right where
they should be. The front yard tree numbers was derived from a windshield survey conducted by the
DNR. They have no idea what’s in people’s backyards, forested areas or trail corridors. The green ash is
native to this area. Chanhassen Hills Park is 50% ash right now. Jill presented a species summary of all
public trees in Chanhassen and gave an overview of Chanhassen’s management plan. The City has had
time to watch other communities work through this infestation and has found a combo approach works
best. You need a combo of removal, treatment, and replanting. It’s too expensive to treat every tree, and
not every tree is worth treating. A combo approach allows you to work it into your current workload and
budget. Trees in poor condition or in a bad location should go immediately. Council asked for more
explanation on bad locations/condition. Studies show that trees less than 10 inches in diameter are not
worth treating. Councilman Laufenburger asked how old a 10 inch tree would be. Jill explained that
depending on growing conditions, 10-15 years. Mayor Furlong asked why we wouldn’t leave a tree in
fair condition less than 10 inches until Emerald Ash Borer is here. Jill Sinclair agreed, but also noted that
we will want to manage the inventory so we don’t have the critical mass problem. Councilman
Laufenburger asked if the Emerald Ash Borer can discern between poor and healthy trees. Jill said maybe
in the beginning, but not really and noted there will be a point where every ash tree is either dead or
treated. It will be present, but managed much like Dutch Elm disease. This will be about 10-15 years
City Council Work Session – February 24, 2014
into treatment and at that point the City may be able to scale back treatment of the ash trees. She
presented an inventory of the health of the city’s ash trees noting that a large majority are in good
condition with a little more than half being bigger than 10 inches in diameter. The City is trying to
manage Emerald Ash Borer within the current workload and budget. The City continues to offer public
education, public works staff have been trained on how to identify Emerald Ash Borer and Jill continues
to attend educational courses. Staff asked for direction to return to the City Council with an Emerald Ash
Borer Management Plan.
Councilman Laufenburger asked what the Arboretum is doing. Jill explained that they are going to wait
until Emerald Ash Borer is confirmed within 5 miles and then treat. The Arboretum doesn’t have poor
condition trees and they will be working harder to save trees as they are an agency responsibility for seed
source. Todd Gerhardt outlined what staff envisions the Emerald Ash Borer Management Plan would
look like. Mayor Furlong inquired whether to treat Ash trees the same way as Elm trees, i.e identifying
and requiring residents to remove them. Jill cautioned that this could be staff-time intensive. Mayor
Furlong asked for more background on how the City dealt with elm tree removals noting that in the last
few years the City has been working on planting non-ash trees near ash trees in parks in anticipation of
Emerald Ash Borer. Councilman Laufenburger asked what are the best replacement trees. Todd
Gerhardt advocated for female Ginkgo trees. Councilman Laufenburger asked about trees that might not
be successful. Jill identified the eastern pin oak as a poor choice for our soils and presently the city has
21% maple trees so we should look towards other types. Mayor Furlong noted that the key is diversity.
Councilman Laufenburger asked for future explanation on the cost to treat each tree over its lifetime. Jill
Sinclair noted that many communities are not planning to treat for the lifetime of the tree but to give more
time for removal and replacement. Mayor Furlong closed by directing Jill Sinclair to continue working
on the Emerald Ash Borer Management Plan by looking at ordinances, costs, phasing, etc.
DISCUSS CSAH 61 IMPROVEMENTS/FLYING CLOUD DRIVE, HENNEPIN COUNTY
PROJECT.
Paul Oehme introduced the project and Jason Sabal and Jennifer Lowry with Hennepin County, the lead
agency for this project and noted that it’s been a great relationship. He explained that Council will
consider municipal consent at their next meeting before reviewing the reconstruction project of Flying
Cloud Drive from Hwy 101 to Carlson Road (3.7 mile segment) with many agencies involved, including
Chanhassen, Carver County, Eden Prairie, MnDOT, Fish and Wildlife, Army Corps of Engineers, and
BWSR. Hennepin County has controlled the corridor since September, 2010. MNDOT has provided
funding for this project through turnback funds. Paul recited statistics regarding traffic on the road noting
that traffic has dropped dramatically since new Highway 212 opened. Hennepin County projects a 2%
increase in trips per year with a good portion of that increase as truck traffic. Crashes are now below
average. He provided an overview of project goals, including mitigating flood impacts, improving
safety, replace the existing pavement, improving water quality, creating a pedestrian friendly corridor to
tie into parks and trail corridors and a list of specific improvements include retaining walls, land bridges,
right-turn lanes, and intersection improvements. Mayor Furlong asked if the road will be built so it can
be striped to four lanes. Jason Sabal said it has the potential to be, but there would need to be intersection
improvements. Mayor Furlong asked if there was room in the corridor, and Jason believed there is.
Mayor Furlong noted that with the improvements at the river crossing being 4-lanes, it would be nice to
have it potentially match up, understanding that the funding source requires specific limitations of
building to the previous standards. Todd Gerhardt explained that some of that would be development
driven and require developer participation. Mayor Furlong noted that the City should just be prepared,
knowing that there will be 4-lanes at either end of the corridor. Jennifer Lowry noted one of the reasons
the trail is set so far back is to allow turn lanes to be added in the future at the lowest possible cost. Paul
showed photos of the proposed retaining walls that will have the least impact to the bluff and the three
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City Council Work Session – February 24, 2014
bridge spans over sections of poor soils. Jason Sabal reviewed the EAW, thanked the Council for having
them at the meeting and explained that Hennepin County asks for municipal consent during the
preliminary part of the project, a little different than how Carver County does it. Hennepin County likes
to know that the City is on board with the plans and that Chanhassen and Eden Prairie will give municipal
consent. Major environmental concerns include wetland impacts, bluff impacts, wildlife that likes to
cross the corridor, and State listed plant species within construction limits. He explained that there are
two watersheds within the construction limits and a couple of ponds being added. One is being built with
the wye project, one near Lions Tap, and one near Richard Anderson park. There are some cultural
resources, though not as much as with the wye project. Paul reviewed the project schedule. Mayor
Furlong asked if Carver County has raised any concern. Paul and Jason agreed they had not. All
agencies are supportive and talks are in progress with property owners for right-of-way acquisition.
Councilman Laufenburger asked when a detour route will be available. Jason Sabal said it will likely be
Pioneer Trail. Paul Oehme discussed staging to not have the entire corridor shut down for 3-4 years.
Mayor Furlong noted that Highway 101 is currently substandard, especially with the traffic it will have to
absorb. Jason Sabal expressed a commitment to keeping the closures to a minimum, but the construction
conditions and soils are very challenging.
Mayor Furlong adjourned the work session at 7:00 p.m.
Submitted by Todd Gerhardt
City Manager
Prepared by Laurie Hokkanen and Nann Opheim
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