HomeMy WebLinkAboutRe_ Impervious Surface Zoning Text Amendments1From:Karen Kill
To:John P. Hanson; Ben Hetzel; Marty Powers; Jack Griffin; "Scollan, Daniel (DNR)"; mmoore@ciwoodbury.mn.us
Cc:Molly Just; Gary Bruns
Subject:RE: Impervious Surface Zoning Text Amendments
Date:Tuesday, July 19, 2022 11:12:08 AM
Attachments:image001.pngimage002.pngimage003.png
Caution: This email originated outside our organization; please use caution.
Ben,
As with VBWD, Brown’s Creek Watershed District considers the water surface of a pool as an impervious
surface. Our stormwater management rules would apply to a land disturbing activity where there is >10,000
square feet of impervious net. A pool would be included in this total. I frequently have people
misunderstand that gravel driveways are impervious. Is there a reason why you are taking this out or do you
define it elsewhere?
BCWD has recently been discussing decks. Currently we include them in the impervious total because they
are generally not built to allow water to flow through them, they are concentrating the flow, often the soil
below is compacted, and we are generally not notified when a resident adds a patio below a second story
deck or adds a screen porch. Nearby city of Stillwater includes decks in the impervious surface total.
As John also inquired, I would be interested to understand why an increase to 25% impervious is being
proposed. I am not clear on whether the Sanctuary development is considered sewered or unsewered since
there is a community sewage for the development. Could you clarify? This small portion of Lake Elmo is the
only portion in BCWD.
Best Regards,
Karen
Karen Kill, Administrator
Brown’s Creek Watershed District
455 Hayward Ave N
Oakdale, MN 55128
651-331-8316 (cell)
From: John P. Hanson [mailto:JHanson@barr.com]
Sent: Monday, July 18, 2022 4:48 PM
To: 'Ben Hetzel' <BHetzel@lakeelmo.org>; Marty Powers <MPowers@lakeelmo.org>; Jack Griffin
<Jack.Griffin@focusengineeringinc.com>; 'Scollan, Daniel (DNR)' <daniel.scollan@state.mn.us>; Karen Kill
<KKill@mnwcd.org>; mmoore@ciwoodbury.mn.us
Cc: Molly Just <MJust@lakeelmo.org>; Gary Bruns <Gary.Bruns@co.washington.mn.us>
Subject: RE: Impervious Surface Zoning Text Amendments
Hi Ben,
Thanks for providing the opportunity to comment on these proposed changes.
The Valley Branch Watershed District considers the water surface of a pool an impervious surface, butVBWD doesn’t consider a pool a structure. These VBWD definitions require stormwater management andvegetative buffers be considered with pools but minimum elevations are not considered.
While unclear, it appears Lake Elmo considers a swimming pool a structure. (City definition of structure isanything constructed or erected on the ground or attached to the ground or on-site utilities, including, butnot limited to, buildings, factories, sheds, detached garages, cabins, manufactured homes, signs, recreationvehicles not meeting the exemption criteria specified in LEC 100.00.090(c)(1), and other similar items.) If aswimming pool is considered a structure by the City, it appears the City would require the lowest elevationof pool to be at least 2 feet higher than the adjacent public water’s 100-year flood level based on Table 17-3of the City’s Shoreline Management Overlay District code. Is this the City’s intent? If not, the City mightwant to specifically exempt swimming pools from the minimum floor elevation requirement.
Has the City evaluated the implications to water resources with the proposed change in maximum amountof impervious surface coverage? Why is 25% being proposed? The proposal would allow more impervioussurfaces to unsewered areas around Lakes DeMontreville, Olson, Jane, and Elmo. These lakes are the jewelsof the many lakes and ponds in the City. Increases in impervious surfaces without thoughtful mitigationcould negatively affect these lakes.
As the City reviews its requirements, I suggest that the City consider requiring the bottoms of septic tanks,drain fields, etc. be at least 2 feet higher than the adjacent water’s 100-year flood level. Perhaps City codealready requires this based on the City’s definition of structure.
Thanks,
John
John P. Hanson, PE
Valley Branch Watershed District Engineer
Barr Engineering Co. | 4300 MarketPointe Drive | Bloomington, MN 55435 office: 952.832.2622 | cell: 612.590.1785 JHanson@barr.com | www.barr.com | www.vbwd.org
From: Ben Hetzel <BHetzel@lakeelmo.org>
Sent: Monday, July 18, 2022 3:49 PM
To: Marty Powers <MPowers@lakeelmo.org>; Jack Griffin <Jack.Griffin@focusengineeringinc.com>; 'Scollan,
Daniel (DNR)' <daniel.scollan@state.mn.us>; John P. Hanson <JHanson@barr.com>; karen.kill@mnwcd.org;
mmoore@ciwoodbury.mn.us
Cc: Molly Just <MJust@lakeelmo.org>
Subject: Impervious Surface Zoning Text Amendments
CAUTION: This email originated from outside of your organization.
All,
The City of Lake Elmo has self-initiated zoning text amendments in regards to impervious surfaces. I have
attached copies of the code to be amended with a brief description of each below:
1. Amend Section 1.08 Definitions to change Impervious Surface definition as shown below:
Impervious surface means any structure or surface which interferes to any degree with thedirect absorption of water into the ground, including, but not limited to, building footprints,sidewalks, paved or gravel driveways and parking areas, patios, sport courts, or any othersimilar surface. Decks, pervious landscaping fabric, the water surface of pools, andretaining walls shall not be included as impervious surface.
2. Amend Section 105.12.1260 Shoreland Management Overlay District Table 17-3 to change maximum
impervious surface lot coverage from 15% to 25% for unsewered lots classified as Recreational
Development Shoreland :
Please have your feedback back to me by
Wednesday, August 3rd!
Ben Hetzel City PlannerCity of Lake Elmo3800 Laverne Ave. N.Lake Elmo, MN 55042651-747-3911