HomeMy WebLinkAboutEngineer Letter 03062023
February 24, 2023
(Revised March 6, 2023)
Josh Prust
Valdes Lawn Care & Snow Removal
Submitted by email: jprust@valdeslawn.com
RE: Timber Retaining Wall – Variance Review Comments
Project Location: 2815 Casco Point Road, Orono, Minnesota
Project No. 22-6589
Dear Mr. Prust:
At your request, this letter is being provided to address several comments and questions that came out of
the recent City of Orono Planning Commission meeting regarding the recently constructed timber
retaining walls at the above property. Revisions in this letter include clarifications to my conclusions and
recommendations.
The comments and questions relevant to my role in this project are as follows:
A. Your engineer should provide an opinion regarding the overall added width of the walls. The
opinion should address whether or not the additional width beyond the previously existing
walls is necessary to maintain stability of the slope, or can they be reduced?
B. Additionally, based on the conversation last night, I recommend that your engineer provide an
opinion on the two options for the top of the slope, adding the 7th wall, or increasing the
height of the 6th wall.
Regarding the first question about the additional length of wall that was added to the previously existing
walls, it is my professional opinion that the additional wall length added was necessary to maintain the
stability of the slope.
- Based on photos you provided of conditions present prior to the construction of the new
tiered timber wall system, there was already significant, on-going erosion and surface water
control issues on the adjacent properties.
- Numerous trees had exposed roots and the slope had areas of exposed soil.
- The decision by your company to increase the length of the walls have improved surface
water control and soil retention when compared to the previous walls.
- Once completed (i.e. walls finished and erosion control established), the new construction will
also have improved the grading along the adjacent property lines.
- The walls as they were designed and as they appear to have been built have a significant
design components to them. They are engineered to industry design standards and
incorporate the necessary tiebacks and deadmen for which extensive excavation is required.
For the second question about the options of adding a 7th wall versus increasing the height of the 6th wall,
it is my professional opinion that either option would be feasible and beneficial.
- The addition of a 7th wall was approved through an emergency repair exception by the City of
Orono on November 28, 2022.
- The emergency repair work was not able to be completed due to heavy snowfall and frozen
ground.
2815 Casco Point Road, Orono, Minnesota
February 24, 2023 (Rev. March 6, 2023)
Page | 2
- As an alternative, I prepared a design for the option to add height to the existing 6th wall to
you on December 9, 2022. This is also a good option to reduce the steepness of the slope at
the top of the wall.
- Adding height to the 6th wall versus building a 7th wall would be better as it could result in less
soil disturbance and excavation.
Refer to my previous letters and design reports for additional information. All previous terms and
conditions apply. Thank you.
Sincerely,
Paul Schimnowski, P.E.
MN #40126
I hereby certify that this plan, specification, or report was prepared
by me or under my direct supervision and that I am a duly Licensed
Professional Engineer under the laws of the State of Minnesota.
Paul Schimnowski, P.E.
Date: March 6, 2023 License #: 40126 (MN)