HomeMy WebLinkAboutPC Report 8-22-22- Impervious (2)1
STAFF REPORT
DATE: 08/22/2022
PUBLIC HEARING
ITEM#: 4a
TO: Planning Commission
FROM: Ben Hetzel, City Planner
REVIEWED BY: Molly Just, Planning Director
AGENDA ITEM: Impervious Surface Text Amendments
BACKGROUND:
At their July 12, 2022 workshop, the City Council had discussed the City’s definition of impervious
surface. In preparation for the workshop, staff researched and compared the City’s definition and
impervious surface allocations with other communities. The findings of the research prompted the City
Council to direct staff to draft the proposed amendment to the City’s definition for impervious surface and
increase the maximum allowed impervious surface in unsewered shoreland areas.
ISSUE BEFORE THE PLANNING COMMISSION:
The Planning Commission is being asked to hold a public hearing, review, and make a recommendation to
City Council on the proposed text amendments.
PROPOSAL DETAILS/ANALYSIS: IMPERVIOUS DEFINITION
Section 1.08.010 defines impervious surface as any structure or surface which interferes to any degree with
the direct absorption of water into the ground, including, but not limited to, building footprints, sidewalks,
paved or gravel driveways and parking areas, patios, sports courts, or any other similar surface. Decks,
pervious landscape fabric, and retaining walls shall not be included as impervious surface.
The current definition aligns with the MN DNR shoreland model ordinance definition and a majority of
other local governments.
Staff found that many other communities do not list specific examples of impervious surfaces. The City
Council feels examples in the current definition are necessary and may be confusing
PROPOSED DEFINITION CHANGES:
Impervious surface means any structure or surface which interferes to any degree with the direct 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 other similar surface. Decks, pervious landscaping
fabric, the surface water of pools and retaining walls shall not be included as impervious surface.
PROPOSAL DETAILS/ANALYSIS: MAXIMUM IMPERVIOUS LOT COVERAGE
Section 105.12.1260(c)(3) Table 17-3: Shoreland Standards currently restricts unsewered lots to a
maximum of 15 percent, while sewered lots are allowed a maximum of 30 percent. This results in a high
number of variance requests being submitted to exceed to the maximum 15 percent. The intent of this
amendment is to reduce the number of variance requests, while not exceeding the maximum 25 percent
2
allowable per MN Statute 6120.3300 and the DNR Model Ordinance. It is appropriate when a community
receives many variance requests from the same standard for that community to review whether the standard
should by changed.
The following table depicts the impervious allowance in the Shoreland in Lake Elmo and other
communities.
Maximum Impervious Lot
Coverage
LAKE ELMO 30% Sewered
15% Unsewered
WOODBURY Riparian 50%
Nonriparian 30%
HUGO 25%
WHITE BEAR
LAKE
30%
FOREST LAKE 25%
STILLWATER 25%
MINNETONKA Within 150 ft of HWL 30%
Outside 150 ft of HWL 75%
MAHTOMEDI Lots before March 3, 1999 35%
Lots after March 3, 1999 25%
TONKA BAY 25%
LINO LAKES Single and Two Family 30%
Triplex/Townhomes 35%
Commercial and Industrial 60%
CHISAGO CITY Residential 25%
Commerical and Industrial 70%
PROPOSED CHANGES
Section 105.12.1260 Shoreland Management Overlay District
Table 17-3: Shoreland Standards
Shoreland Classification
Standards Recreatio
na l
Developm
e nt
Natura
l
Envir
on
ment
Tribut
ary
Rive
r
3
Minimum structure setback from county, state or federal
road right-of-way 50 feet 50 feet 50 feet
Minimum setback from right-of-way line of town road, public
street, or other roads or streets not classified
20 feet 20 feet 20 feet
Minimum structure setback from an unplatted cemetery
or historical sitea 50 feet 50 feet 50 feet
Minimum Structure Setback From The Ordinary High Water Level (OHWL):b, c, e
Seweredd 75 feet 150 feet 50 feet
Unseweredd 100
feet
150
feet
100 feet
Minimum structure setback from top of bluff 30 feet 30 feet 30 feet
Minimum septic system setback from OHWL 75 feet 150
feet
75 feet
Minimum low floor elevation above the 100-
year flood elevation 2 feet 2 feet 2 feet
Maximum Impervious Lot Coverage:
Sewerede 30
percent
30
perce
nt
30 percent
Unsewered 15 percent
25 percent
15
Perce
nt
25
perce
nt
15 percent
25 percent
AGENCY REVIEW
Staff distributed the proposed comments for agency review and received comments from the following:
Valley Branch Watershed District (email provided in packet)
Browns Creek Watershed District (email provided in packet)
City Engineer (email provided in packet)
PUBLIC COMMENT
A hearing notice was published in the Stillwater Gazette on August 12, 2022. No public comments has
been received at this time.
4
FISCAL IMPACT
None
OPTIONS
Recommend approval of the proposed amendments.
Recommend changes to the proposed amendments.
Recommend denial of the proposed amendments.
RECCOMENDATION
Staff recommend that the Planning Commission recommend approval of the proposed text amendments as
presented.
“Motion to recommend adoption of the proposed text amendment, amending the impervious surface
definition in Section 1.08.010 Definitions as presented.”
“Motion to recommend adoption of the proposed amendment as presented, amending Section
105.12.1260 Shoreland Management Overlay District, Table 17-3: Shoreland Standards to increase the
maximum impervious lot coverage for an unsewered lot to 25%.
ATTACHMENTS
1. Section 1.08.010 Definitions (Draft)
2. Section 105.12.1260 Shoreland Management Overlay District, Table 17-3: Shoreland Standards (Draft)
3. MN DNR Shoreland Model Ordinance
4. Valley Branch Watershed District comments
5. Browns Creek Watershed District comments
6. City Engineer comments
5