HomeMy WebLinkAbout2015-03-05 Arborist Comments - Fowarded to Applicant 03-19-2015 ( Julie Hultman
liFrom: Julie Hultman
Sent: Thursday, March 19, 2015 2:48 PM
To: 'kyle.colvin @metc.state.mn.us'
Cc: 'kdwidin @comcast.net'; Eric Johnson
Subject: FW:Wastewater Treatment Plant Outfall Project - Review of Plans Tree
Removal/Replacement
Mr.Colvin-
Please see Arborist Kathy Widin's comments below.
Thank you,
it Julie Hultman
City of Oak Park Heights
j Original Message
From: K.D.Widin [mailto:kdwidin@comcast.net]
Sent:Thursday, March 05,2015 10:07 PM
To: Eric Johnson; Mark Vierling(E-mail);Andrew Kegley; Betty Caruso;Julie Hultman;Scott Richards;Chris Long;Jennifer Pinski; Lisa
Danielson
Subject:Wastewater Treatment Plant Outfall Project-Review of Plans Tree Removal/Replacement
OPH Staff-
I was recently asked to review plans sent to the City re:a replacement of an outfall pipe from the Wastewater Treatment Plant to
the St.Croix River. The project includes removal of a number of trees along the pipeline corridor. On Tues.3/3/15, Lisa Danielson
(Arborist in
training)and I visited the site with personnel from MCES and inspected the trees designated to be removed. Following are my
observations and recommendations related to the tree removal and replacement for this project. The Tree Protection Ordinance for
the City of Oak Park Heights will apply to this project.
1. Based on the site inspection,the tree inventory for the construction area is accurate,the species and sizes of trees on the site
correlate well with the tree species and sizes in the inventory. Most trees being removed are silver maple and cottonwood.
2. Inches of Significant Trees Being Removed in the Construction Zone:
an estimate based on the list in the tree inventory is 492 diameter inches. Some of the trees in the inventory list were 6 in.,which is
not considered significant. Silver maples and cottonwoods are significant at 12 in.diameter in a flood-plain site. Others were listed
in groups of trees with a range of diameters, rather than being listed separately,so I could only estimate those diameter inches. This
tree removal would be offset by diameter inches of significant trees being preserved on the site.
3.Tree Protection Fencing as described in the project specifications is adequate to protect trees to be preserved which are close to
the construction zone and should be placed at the drip-line of trees to be preserved,as described in the specifications.
4.Tree Replacement-the project proposes a range of flood plain tree species to be planted once construction is completed. This list
is acceptable and will increase species diversity in that area. The opinion of Oak Park Hts.staff is that the sizes should be increased
(2 in.caliper is required in the Tree Protection Ordinance for replacement
trees)and that the Tree Replacement Requirement should be calculated based on significant trees on the whole site,which is
standard practice for development sites on wooded parcels within the City. This will require an inventory of all significant trees on
the parcel (see item#5).
5.The tree inventory included only the construction area, not the whole site. In order to calculate the Tree Replacement
Requirement for this project, per the Oak Park Heights Tree Protection Ordinance,an inventory of all the significant trees(deciduous
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trees 8 in.in diameter and greater(silver maple and cottonwood in floodplain area 12 in.,or evergreens 10 ft.tall and greater)
would need to be done for the entire property. A value needed for the Tree Replacement Requirement calculation is"total diameter
inches of significant trees situated on the land". The trees being preserved on the rest of the site would reduce the tree
replacement requirement for the project.
6. Replacement of Trees on the Site or Payment in Lieu of Tree
Replacement: The replacement trees should,if possible, be planted near the area where trees were removed in order to preserve
the function of preventing soil erosion and mitigating effects of floodwaters. It is understood that trees cannot be planted over the
pipeline. Trees could also potentially be planted elsewhere on the property. The Oak Park Heights Tree Protection Ordinance also
describes the option of"Payment in Lieu of Tree Replacement"at$50. per diameter inch of the Tree Replacement Requirement if
not all the trees can be planted on the site.
7.Tree Protection(Rodents/Deer)-spraying of repellents is listed in the project specifications for a one-time application. A cylinder
of
1/4 in. mesh hardware cloth from just below the soil level up to the lowest branches,secured to lathe or re-bar stakes about 6 in.
out from the trunks of trees will prevent more animal damage than a one-time application of a repellent.
Please contact me if you have any questions regarding this plan review or site inspection. Please pass this review on to the
developer.
Kathy Widin
Arborist
City of Oak Park Heights
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