HomeMy WebLinkAboutAgenda 06_MS-21-04_1195 Shelburne Rd_Larkin Realty_stream alt#MS-21-04
Staff Comments
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CITY OF SOUTH BURLINGTON
DEVELOPMENT REVIEW BOARD
MS-21-04_1195 Shelburne Rd_Larkin Realty_stream
alt_2021-10-25.docx
DEPARTMENT OF PLANNING & ZONING
Report preparation date: October 27, 2021
Plans received: August 9, 2021, October 25, 2021
1195 Shelburne Road
Miscellaneous Application #MS-21-04
Meeting date: November 2, 2021
Owner
Allenwood Inn, LLC
5 Holmes Road
South Burlington, VT
Applicant
Larkin Realty
410 Shelburne Road
Burlington, VT 05401
Property Information
Tax Parcel 1540-01195
Residential 1 - Lakeshore Zoning District
95.34 ac
Engineer
Civil Engineering Associates, Inc.
10 Mansfield View Ln
South Burlington, VT 05403
Location Map
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Staff Comments
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PROJECT DESCRPTION
Miscellaneous permit application #MS-21-04 of Larkin Realty for stream alteration and stormwater
drainage modifications, 1195 Shelburne Road.
CONTEXT
The project is located west of Shelburne Road and consists of rerouting an existing unnamed stream.
The applicant has stated that the purpose is to relocate the flows downstream of an existing eroded
area. The property consists of residential use. The project is subject to the Land Development
Regulations pertaining to 12.01C surface water buffers, 12.01G watercourse alteration and relocation,
and 12.02 wetland protection.
As illustrated in the above aerial image, the stream begins east of the railroad and east of Fayette Road,
passes under Fayette Road in a culvert, runs through the wetland adjacent to Olde Orchard Park, is
culverted across the railroad, and then is discharged into a Class II wetland on the subject property
before flowing to Lake Champlain.
The applicant’s proposal is to extend the culvert downstream of the railroad for an additional 350 feet,
undergrounding the perennial stream, widen the stream channel at the new discharge, and place
boulders in the stream channel downstream of the new discharge. The extended culvert would largely
bypass the Class II wetland and reduce the natural portion of the stream by 430 ft (350 ft of culvert and
80 ft of armoring), though the applicant is proposing a 4-inch low flow outlet which would continue to
discharge to the wetland. No information about flows in either the large 36-inch culvert or the 4-inch
low flow outlet has been provided. Staff estimates, based on available contour and stream data, that
the watershed area of the railroad culvert is approximately 200 acres.
PERMIT HISTORY
It appears the most recently approved permit for this property was to install erosion control measures
(SD-07-13) though it is difficult to be sure because of multiple properties sharing the same address on
Shelburne Road.
These staff comments were originally prepared for the September 8, 2021 hearing. The applicant twice
requested continuation in order to allow more time to prepare responses. Responses were not provided
to Staff until 2 days before packet publication. In order to provide the most expeditious review given the
very short timeline, this report is formatted to provide the original analysis, the applicant’s response, and
Staff’s analysis thereof.
Staff has also added a summary of imminent regulatory changes under “Recommendations” should the
Board wish to use that information in their decision on whether to close or continue the hearing.
COMMENTS
Stormwater Superintendent Dave Wheeler and Development Review Planner Marla Keene (“Staff”) have
reviewed the plans submitted on 8/9/2021 and 10/25/2021 and offer the following comments.
Numbered items for the Board’s attention are in red.
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Staff Comments
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Generally speaking, Staff considers there are a number of potential issues with the proposed stream
alteration, many of which are technical in nature. Staff has therefore, three principal comments on this
application.
1. Insufficient information is provided to justify the proposed impacts. Staff recommends the Board
require the applicant to provide the missing information.
10/25 Applicant Response: This correspondence seeks to supplement and clarify the applicant’s
position on the proposed project.
Staff analysis of 10/25 Response: As noted in the cover memo, Staff considers the Board must make
a determination on whether the proposed impacts are allowable. This is addressed under 12.01C(4)
below. Staff considers no explicit discussion of this comment is required, as it is addressed
elsewhere herein.
2. Once the missing information is provided, Staff considers the Board may wish to invoke technical
review (discussed herein) and defer detailed discussion of many staff comments until the technical
review is complete. The City Stormwater Section has also reviewed the proposal and supports
technical review.
10/25 Applicant Response: This is the Development Review Board’s prerogative. As stated earlier,
this has been reviewed by the City’s Stormwater technical staff as well as the State of Vermont Stream
Alteration Engineer as it relates to the State’s lack of jurisdiction over the project.
Staff analysis of 10/25 Response: Based on the additional information that has been provided, Staff
considers the Board may wish to invoke a more limited technical review than originally recommended
only if they find the project to be allowable under 12.01C(4). Specifically, Staff recommends a
technical review to evaluate whether the proposed project meets the stated objectives of the
applicant without adverse impacts to the environmental priorities enumerated in the relevant criteria
of the LDR, or whether an alternative approach would accomplish the same objective. Staff considers
no explicit discussion of this comment is required, as it is addressed elsewhere herein.
3. Review of the South Burlington Natural Resource Conservation Committee (NRCC) is required. Staff
recommends the Board refer the application to the NRCC once the missing information is provided,
and include any specific requests in their referral. The NRCC meets the first Wednesday of each
month, and materials are due to them a week before their meeting.
10/25 Applicant Response: The jurisdictional opinion that we received from Zoning Administrator
was that the only section of the Land Development Regulations that apply to the project is Section
3.12 – Alteration of Existing Grade. A copy of the request for jurisdiction opinion and the resulting
determine are attached. Staff has claimed that the application pending before the board is different
than that offers for the jurisdictional opinion. This is true in only that features were removed from
the plan based on the technical review of the project by the City Stormwater Utility which made the
project more benign rather than more intensive that the original JO submittal. Section 3.12 of the
LDR’s calls for an erosion prevention and sediment control (EPSC) submittal and review.
Staff analysis of 10/25 Response: The City does not issue jurisdictional opinions, nor was any
implication made that only section 3.12 of the LDR applied to the project. Further, 24 V.S.A. §
4411(b) specifies that “all zoning bylaws shall apply to all lands within the municipality other than
as specifically limited or exempted in accordance with specific standards included within those
bylaws and in accordance with the provisions of [chapter 117].” Any guidance given to an applicant
prior to submission and complete review of a formal application is a direction on how to proceed.
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Should the Board have any question as to whether the applicant’s objection has merit, the
applicant’s request for information and the Zoning Administrator’s response is included in the
packet for the board. As discussed herein, the project is subject to 12.01 as it proposes work within
50 ft of the centerline of a stream. Specific comments pertaining to required review by the NRCC
are included below. Staff considers no explicit discussion of this comment is required, as it is
addressed elsewhere herein.
12.01 GENERAL STREAM AND SURFACE WATER PROTECTION STANDARDS
C. Surface Water Buffer Standards (“Stream Buffers”)
(1) Applicability. The requirements of this Section shall apply to all lands described as follows:
(a) - (b) N/A
(c) All land within fifty (50) feet horizontal distance of the centerline of any minor stream
(d) - (e) N/A
Both the upstream and downstream ends of the proposed culvert are by definition within 50-ft
of the centerline of the stream, since the culvert conveys the stream itself, therefore these
standards apply.
(2) General standards. It is the objective of these standards to promote the establishment of
heavily vegetated areas of native vegetation and trees in order to reduce the impact of stormwater
runoff, reduce sedimentation, and increase infiltration and base flows in the City’s streams and Lake
Champlain. Therefore, except as specifically permitted by the DRB pursuant to the standards in
Section 12.01(C)(3), (C)(4), (D) and/or (E) below, all lands within a required stream buffer defined
above shall be left in an undisturbed, naturally vegetated condition. Supplemental planting and
landscaping with appropriate species of vegetation to achieve these objectives shall be permitted.
The specific standards for the vegetation and maintenance of stream buffers are as follows:
(a) The clearing of trees that are not dead, heavily damaged by ice storms or other natural
events, or diseased, and the clearing of any other vegetation other than invasive species, is
permitted only in conjunction with DRB approval pursuant to (3) or (4) below.
This area is currently maintained as lawn, therefore tree clearing is not an issue.
(b) Any areas within a required stream buffer that are not vegetated or that are disturbed
during construction shall be seeded with a naturalized mix of grasses rather than standard lawn
grass, and shall not be mowed.
4. No information is provided about the seeding to be used in disturbed areas. Staff recommends
the Board direct the applicant to modify their plan to include a specification for naturalized grass
and indicate areas not to be mowed. In the context of the other issues with the proposal, Staff
recommends the Board require this prior to closing the hearing.
10/25 Applicant Response: This is not correct as the specifications included in the application
package (Sheet C3.1) call for a Conservation seed mix to be utilized. The applicant has maintained
this area with a small buffer of unmowed grasses in the steeper embankment areas and will
commit to maintaining this practice.
Staff analysis of 10/25 Response: Staff appreciates the clarification and has confirmed that the
mix specified on sheet C3.1 includes species used in plantings intended to provide erosion control
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and wildlife habitat value. However, the applicant has not proposed a 50-ft unmowed buffer as
required.
No provision is given for previously maintained buffers. The Board has, in the past, provided a
little latitude for a walking path or access to infrastructure, but otherwise, if the Board ultimately
approves this or similar proposal for work within the stream buffer, Staff considers the Board
should require the applicant to modify the plans to provide an unmowed 50-ft buffer on either side
of the stream. As a best practice, Staff also recommends the Board prohibit mowing within the
wetlands.
(c) The creation of new lawn areas within stream buffers is not permitted after the effective
date of these regulations.
Staff considers this criterion not applicable.
(d) N/A – pertains to snow storage
(e) The placing or storing of cut or cleared trees and other vegetation within the stream
buffer is prohibited.
Staff considers this criterion applies but no action is needed.
(3) Expansion of pre-existing structures within stream buffers. The expansion of pre-existing
structures within stream buffers, except as provided in Section D below, shall be permitted only in
accordance with the standards for non-complying structures in Article 3, Section 3.11 of these
Regulations.
Staff considers that the Board may interpret the headwall as a necessary part of the stream
conveyance system and therefore modification of the headwall is not subject to Section 3.11
Non-Conformities.
(4) New uses and encroachments within stream buffers. The encroachment of new land
development activities into the City’s stream buffers is discouraged. The DRB may authorize the
following as conditional uses within stream buffers, subject to the standards and conditions
enumerated for each use. The DRB may grant approvals pursuant to this section as part of PUD
review without a separate conditional use review.
5. Update [new numbered comment]: Staff considers this the most important decision point for the DRB.
The placement of boulders and widening of the stream channel consists of a new encroachment within
the stream buffer, therefore this criterion applies. The Board must determine whether the LDR allows
the applicant to work within the stream buffer under one of the following provisions. If work is not
allowed under one of the following, discussion of the design is moot.
(a) N/A, pertains to agricultural uses
(b) Clearing of vegetation and filling or excavating of earth materials, only to the extent
directly necessitated for the construction or safe operation of a permitted or conditional use on
the same property and where the DRB finds that:
(i) There is no practicable alternative to the clearing, filling or excavating within the
stream buffer; and
(ii) The purposes of this Section will be protected through erosion controls, plantings,
protection of existing vegetation, and/or other measures.
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6. Staff considers that of all the allowable encroachments, this (b) is the most potentially applicable,
and recommends the Board require the applicant to demonstrate why their proposed
encroachment is necessary for the safe operation of a permitted use, demonstrate that there is no
practicable alternative, and that the encroachment will result in greater protection of the stream
buffer. Staff notes that streams naturally meander and channelization of a stream is generally
considered to be a poor environmental practice.
10/25 Applicant Response: This watercourse is an unnamed tributary of Lake Champlain that
begins on the east side of Fayette Drive and then flows behind the Palace 9 Theatre property to a
pond where then it flows through a 36” culvert onto the property of David Farrell on the west side
of the railroad tracks.
The watershed contributing to the stream has an area of nearly 300 acres (0.45 square miles).
Please see the attached ANR Atlas watershed take-off.1
The stream channel downstream of the culvert outlet has experienced significant shore line
erosion. We surmise that this is a byproduct of the large increases in impervious area draining
from this watershed.
In partnership with Eric Farrell and Joe Larkin, Mr. Farrell is looking to maintain base flows in the
stream while diverting the peak flows to a portion of the stream not currently experiencing the
shoreline erosion in the middle sections of the property. The proposed project seeks to eliminate
the erosion and subsequent sediment load to the receiving waters. This technique is an innovative
means of avoiding the traditional stone lining of eroded channels. Vegetative stabilization has
bene overwhelmed by the runoff from this watershed.
The originally submitted plans depict the details of the proposed peak flow rerouting. Pictures of
the existing condition erosion are attached.
Staff analysis of 10/25 Response: The applicant notes that the objective of this project is to
maintain base flows, eliminate erosion and sedimentation. The applicant has included
photographs of the area of concern. Staff notes the existing degraded culvert shown in the
photographs is not proposed for repair; the applicant is instead only proposing to culvert an
additional 350 ft of the existing stream. The Board must determine whether these or any stream
buffer modifications are “directly necessitated for the construction or safe operation of a
permitted or conditional use.” If not, Staff considers the Board must deny the project. If so, the
Board must then determine whether (b) that there is no practicable alternative, and (c) that the
encroachment will result in greater protection of the stream buffer, both of which are discussed in
the remainder of this report.
(c) Encroachments necessary to rectify a natural catastrophe for the protection of the
public health, safety and welfare.
(d) Encroachments necessary for providing for or improving public facilities.
Staff considers encroachments (c) and (d) to be not applicable but has retained them for context.
1 The applicant has calculated the watershed to be around 300 acres using GIS mapping. City Stormwater Staff
reports that the area of Pinnacle at Spear is routed to a watershed to the south, and the area of Stonehedge is
routed to a watershed to the north, thus reducing the tributary watershed area by about one third to 200 acres.
This is a small watershed and therefore Staff considers floodwaters in the stream likely to be tied to surface runoff,
and therefore “peaky.”
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(e) N/A, pertains to public facilities
(f) Stormwater treatment facilities meeting the Vermont Agency of Natural Resources
stormwater treatment standards, and routine maintenance thereof, including necessary
clearing of vegetation and dredging. Evidence of a complete application to the VANR for
coverage under the applicable permitting requirements shall be required to meet this criterion
for encroachment into a stream buffer.
No treatment is proposed therefore this encroachment is not applicable.
(g) – (k) N/A
G. Watercourse Alteration and Relocation.
The applicant provided responses to each of these criteria, shown in blue. Staff notes follow the
applicant’s response.
(1) The alteration or relocation of a watercourse is permitted subject to the approval of the
Development Review Board provided the alteration or relocation:
(a) Is needed to accomplish a clear public purpose or objective;
Applicant response: The purpose of this project is to mitigate the existing erosion issues
caused by an increase in impervious area and stormwater runoff from the lot at 1185
Shelburne Road.
Staff comment: While staff supports erosion prevention, Staff questions whether
bypassing a stream segment and limiting the ability of the watercourse to meander is the
appropriate method for reducing erosion. Further, Staff considers there is no public
impact of the existing erosion or the proposed impacts. Staff considers no Board action
is necessary on this criterion; it is addressed through other topics discussed herein.
(b) Will not reduce the ability of the watercourse to carry or store flood waters adequately;
Applicant response: The project does not propose to reduce the ability of the watercourse
to carry or store flood waters.
7. Staff comment: Discussed further below, Staff recommends technical review of this
criterion. Staff considers the purpose of this project is to direct water away from the in-
stream wetland and therefore the ability of the wetland to carry, and particularly to store,
flood waters will be impacted. Staff recommends the Board require the applicant
demonstrate this project does not reduce flood storage.
10/25 Applicant Response: The watercourse has been significantly impacted by flood
waters to the point where the erosion of the stream has significantly altered its
characteristics. The proposed rerouting of the peak flows around the deteriorated
watercourse will enable the existing stream to restore the eroded areas with vegetation.
Staff analysis of 10/25 Response: Staff considers this response does not demonstrate this
criterion being met. The applicant has indicated that the stream segment being proposed
for bypass is incised and therefore the adjacent floodplain is no longer being accessed.
Staff understands that stream bank erosion is a natural process that can be accelerated
by human impacts. When we build roads, buildings, and parking lots, we increase
impervious surfaces, and more runoff rushes to streams when it rains instead of soaking
into the land. Stream banks are eroded and channels are deepened and widened, and the
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incising stream channel becomes disconnected from its floodplains. Over time, a new
deeper and wider channel will form, and the stream vegetation will recover, but not
before rain carries away huge amounts of sediment. Traditionally there are two
approaches to dealing with an incised stream, the first is to let nature take its course and
the second involves human intervention. Under the proposed project scenario, the
existing floodplain would be cut off from the natural process of stream channel evolution
and any future opportunity for a floodplain reconnection project would likely require
removal of the proposed work. Among the human intervention options, City staff is not
familiar with the practice of bypassing peak flows further downstream, as the stream
cross-section may not be adequate to convey the peak flows without triggering the same
incising that occurred upstream, therefore resulting in downstream erosion. Staff is aware
of alternative design methods to restore stream channels and reconnect floodplains that
mimic more natural systems, such as beaver dam analogs, log vanes, or cross vanes using
natural materials.
If the Board considers the encroachment to be allowed under 12.01C(4) above, Staff
continues to recommend the Board invoke technical review to evaluate the proposal’s
impact on the ability of the watercourse to carry or store flood waters adequately,
including an analysis of potential alternative solutions.
(c) Will not have an adverse impact on downstream or upstream water quality;
Applicant response: The project proposes to reduce erosion which will improve water
quality downstream of this project. This project does not propose to impact water quality
upstream.
8. Staff comment: Discussed further below, Staff recommends technical review of this
criterion. Staff considers the wetland itself provides sediment removal, therefore without
further documentation, it is not known whether bypassing the wetland has an overall
reduction in sediment or simply reduces sediment deposition in the short segment where
flows are removed.
10/25 Applicant Response: Due to the historical stream cutting the wetland is located
well above the existing stream channel.
Staff analysis of 10/25 Response: As discussed above, implementing alternative stream
channel restoration methods would likely result in reconnection of the stream flows to
the existing wetland. Bypassing the stream would only further cut-off the wetland from
peak flows during significant rain events. Further, no evaluation of the downstream
channel is provided other than a note that it is “stable.” Will the new outfall create
erosion? Staff considers it possible that the proposed project will simply result in moving
the existing erosion downstream of its current location, or will have no impact at all given
the degraded condition of the culvert upstream of the proposed flow splitter manhole.
If the Board considers the encroachment to be allowed under 12.01C(4) above, Staff
continues to recommend the Board invoke technical review of whether the proposed
project will have an adverse impact on water quality and whether the proposed project
will have the desired effect of reducing erosion.
(d) Will not affect adversely the use and enjoyment of adjacent properties;
Applicant response: This project will not adversely impact any adjacent properties.
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Staff comment: Staff considers this criterion met.
(e) Will not affect adversely the habitat value of the watercourse or immediately adjacent
areas or wetlands.
Applicant response: This project will not adversely impact any of the existing wetlands as
the wetland does not rely on the existing drainage outfall as its source, but on the natural
drainage of the watershed around the existing site including the existing
9. Staff comment: Discussed further below, Staff recommends technical review of this
criterion. While the wetland may be not impacted, addition of 350-ft of culvert may have
a potential impact on existing or future aquatic organism passage.
10/25 Applicant Response: The existing drainage way will along the east side of the
wetland will be retained. It is the peak flows that are being rerouted. There is already 830
feet of upstream culvert which this drainage passes through before arriving at the project
area.
Staff analysis of 10/25 Response: Based on discussion with City Stormwater Staff,
potential impacts to habitat include adverse impacts to fish habitat and to aquatic
organism passage (reduction of the upstream culvert from the wetland from 36” to 4”).
As discussed above, repair or removal of a portion of the upstream culvert may result in
the same desired effect while improving habitat value.
If the Board considers the encroachment to be allowed under 12.01C(4) above, Staff
continues to recommend the Board invoke technical review of whether the proposed
project will have an adverse impact on habitat value of the watercourse, including an
analysis of potential alternative solutions.
(2) In making findings relative to these criteria, the DRB shall be authorized to invoke technical
review by a professional in hydrology or geomorphology, and/or to rely on the issuance of a Stream
Alteration Permit issued by the Vermont Department of Environmental Conservation as evidence
that the above criteria have been met.
10. Vermont DEC has determined that no Stream Alteration Permit is needed because less than 10 cubic
yards of fill or excavation are proposed. The City of South Burlington, however, has no such exemption.
10/25 Applicant Response: The City did provide a determination that the project was only subject to
Section 3.12 of the LDRs.
Staff analysis of 10/25 Response: This assertion has already been discussed. No such determination
was made. Technical review has already been recommended. Staff considers no explicit discussion
of this comment is required.
(3) The South Burlington Natural Resources Committee shall in a timely manner review and
make advisory comments to the DRB on any application made pursuant to this section.
This criterion is discussed above. Staff recommends the Board continue the hearing to no sooner
than November 2 to accommodate the schedule of the NRCC, which includes an allowance for the
NRCC to provide written advisory comments after their October 6 meeting.
11. Update [new numbered comment]: The timeline described in this recommendation is no longer
valid. The applicant has not pursued review by the NRCC. This is the only place in the Land
Development Regulations where a committee is required to review an application. The Board must
ultimately decide whether to close (and deny) the application or continue the hearing to allow the
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applicant further opportunity to address this requirement. Discussion of the repercussions of each
choice is provided in the recommendations section of this report.
SECTION 12.02 WETLAND PROTECTION STANDARDS
These standards apply to all lands within 50-feet of a wetland.
(1) Consistent with the purposes of this Section, encroachment into wetlands and buffer areas is
generally discouraged.
(2) Encroachment into Class II wetlands is permitted by the City only in conjunction with issuance
of a Conditional Use Determination (CUD) by the Vermont Department of Environmental
Conservation and positive findings by the DRB pursuant to the criteria in (3) below.
(3) Encroachment into Class II wetland buffers, Class III wetlands and Class III wetland buffers, may
be permitted by the DRB upon finding that the proposed project’s overall development, erosion
control, stormwater treatment system, provisions for stream buffering, and landscaping plan
achieve the following standards for wetland protection:
Based on the provided plans, it is unclear the amount of proposed wetland and wetland buffer impact.
At the upstream end of the proposed culvert extension, the applicant has indicated an area to
“remove ex. headwall and in all eroded areas, including the plunge pool, restore stream channel
geometry to match the north (minor) leg of the stream confluence 100’ south of the headwall.” No
limits of this work are shown, though it does appear to overlap with the Class II buffer. Further, no
information is provided as to what it means to “restore stream channel geometry,” including but not
limited to proposed surface treatment.
At the downstream end of the proposed culvert extension, it appears there are no proposed Class II
wetland impacts, but there is a small Class III wetland whose buffer will be impacted, though impacts
are not quantified and the required 50-ft buffer is not shown.
12. Staff recommends the Board require the applicant to show the 50-ft wetland buffer and to show and
quantify the area of wetland and wetland buffer impacts on the plans.
10/25 Applicant Response: This has been added to Sheet C1.1
Staff analysis of 10/25 Response: The revised plan confirms that impacts to the Class II wetland buffer
(shown in orange) are not proposed, and that impacts to the Class III wetland buffer (show in pink)
are proposed. No area of impacts is provided. Staff notes that wetland impact criteria are largely
similar to the stream impact criteria.
If the project is ultimately approved, it has been the Board’s practice to provide a specific area of
impact and the Board should therefore require the applicant to provide such a number.
(a) The encroachment(s) will not adversely affect the ability of the property to carry or
store flood waters adequately;
13. As discussed above, Staff considers the purpose of this project is to direct water away from
the wetland and therefore the ability of the wetland to carry, or particularly to store, flood
waters will be impacted. Staff recommends the Board require the applicant demonstrate
compliance with this criterion.
10/25 Applicant Response: The erosion of the stream channel has caused the bottom of
the stream to drop well below the adjacent wetland. There is no evidence that sediment
retention (and flood storage) is a feature of this wetland under the existing conditions.
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Staff analysis of 10/25 Response: As discussed above, implementing alternative stream
channel restoration methods would likely result in reconnection of the stream flows to
the existing wetland. Bypassing the stream would only further cut-off the wetland from
peak flows during significant rain events.
(b) The encroachment(s) will not adversely affect the ability of the proposed stormwater
treatment system to reduce sedimentation according to state standards;
14. The removal of flow from the wetland may adversely impact sediment reduction. Staff
recommends the Board require the applicant demonstrate compliance with this criterion.
10/25 Applicant Response: The drainage way from the north will continue to drain through
this area as well as the base flows enabled through the proposed diversion structure. The
point of interest is that the stream channel has been cut down to the point where is
enabling better drainage of the wetland.
Staff analysis of 10/25 Response: Staff considers the applicant’s response does not address
the criterion. Staff largely considers this criterion will be met when the criteria of 12.01G
are met.
That being said, the applicant notes a drainage way from the north. If the applicant
continues to pursue the currently proposed design, it may be necessary to understand the
hydrology of the wetland as it pertains to contributions from each of the drainage ways
(the stream and the ditch to the north). Unless the Board determines there is merit to the
currently proposed design, Staff considers there is no need to pursue this analysis at this
time.
(c) The impact of the encroachment(s) on the specific wetland functions and values identified
in the field delineation and wetland report is minimized and/or offset by appropriate
landscaping, stormwater treatment, stream buffering, and/or other mitigation measures.
15. The wetland report has not been provided therefore it is not possible to evaluate compliance
with this criterion. Staff recommends the Board direct the applicant to provide a description
of the functions and values of each of the Class II and Class III wetlands and demonstrate how
those functions and values are minimized and mitigated.
10/25 Applicant Response: A wetland report was not prepared originally since there were no
impacts to the Class II wetlands. Photos of the Class II wetlands and Class III wetland are
attached. The ten wetland functions and values are as follows.
1. Water Storage - Because of the channel erosion which has lowered the normal water level
below the wetland, the wetland appears to provide little storage for the main branch.
2. Water Quality Protection – No reduction in the size of the wetland is proposed and will
continue to filter runoff from the developed areas to the west.
3. Fish Habitat – The project will maintain minimum stream flows in the main channel adjacent
to the wetland.
4. Wildlife Habitat – The project will not reduce any of the wildlife habitat in the wetlands.
5. Sensitive Species – No sensitive species have been mapped in this area.
6. Exemplary Communities – There are no exemplary communities identified in the State
database.
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7. Education and Research – The wetlands are marginal as it relates to providing a
demonstration of an exemplary wetland. The project will not reducte this opportunity for
education.
8. Recreation – These wetland do not provide any significant recreational opportunities and
what may exist will not be reduced will not be reduced.
9. Open Space- The wetland complex will remain as an open undeveloped area.
10. Erosion Control. The wetland itself does provide this benefit within the main body of the
wetland but the edge of the wetland has been impacted by the historical erosion of the
drainage way edge. The proposed re-allocation of the peak flows away from the edge of the
wetland will better allow the embankment to stabilize.
Staff analysis of 10/25 Response: Staff appreciates the detailed breakdown for the purpose
of evaluating direct and indirect impacts to the Class II and Class III wetlands. It is understood
that the Class II wetland and wetland buffer are not directly impacted, but Staff agrees with
the applicant that an analysis should include indirect impacts due to rerouting flows. Staff
agrees with the applicant’s evaluation except for as pertains to functions 1. Water Storage
and 10. Erosion Control, discussed elsewhere in this document. Staff considers no explicit
discussion of this comment is required.
12.04E(2) Drainage Structures To Accommodate Upstream Development – Culverts or other
drainage facilities shall be of sufficient size to accommodate potential runoff from the entire
upstream drainage area, whether or not all or part of the upstream area is on the applicant’s lot or
the parcel subject to the application. In determining the anticipated amount of upstream runoff for
which drainage facilities must be sized, the applicant shall design the stormwater drainage system
assuming the total potential development of upstream drainage areas. All drainage structures shall
be designed to, at a minimum, safely pass the twenty-five year, twenty-four hour (4.0 inch) rain
event. The applicant’s engineer shall provide such information as the Stormwater Superintendent
or his designee deems necessary to determine the adequacy of all drainage structures.
16. The applicant has not demonstrated whether the proposed culvert extension can safely pass the 25-
year 24-hour rain event. Staff notes a longer, flatter culvert has less capacity than a short, steep
culvert. Staff recommends the Board require the applicant to provide a computation showing the
culvert meets this criterion.
10/25 Applicant Response: The bypass was designed to accommodate the flows from the existing 36”
diameter pipe. To meet the Q25 year design storm the pipe would need to be 72” diameter. This is
larger than anything in the existing conveyance system.
Staff analysis of 10/25 Response: As noted above, the drainage area is only about 2/3 the size the
applicant estimates. The culvert under the railroad tracks is 60” diameter, which may accommodate
the 25-year 24-hour rain event.
Given the aggregation of above comments, if the Board considers the encroachment to be allowed
under 12.01C(4) above, Staff continues to recommend the Board invoke technical review to evaluate
whether the potential improvements could reasonably accommodate the 25-year flow. The proposed
design should not, in any case, reduce the capacity of the existing system. The applicant has not yet
demonstrated that will be the case. As previously noted, a longer flatter culvert has less capacity than
a shorter steeper culvert.
#MS-21-04
Staff Comments
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Update [new section]: CONDITIONAL USE REVIEW
Pursuant to Section 12.01C(4) of the South Burlington Land Development Regulations (New Uses and
Encroachments Within Stream Buffers), the proposed use shall be reviewed as a conditional use and
shall meet the following standards of Section 14.10(E):
14.10E General Review Standards
The Development Review Board shall review the proposed conditional use for compliance with all
applicable standards as contained in these regulations. The proposed conditional use shall not result in
an undue adverse effect on any of the following:
(1) The capacity of existing or planned community facilities.
Staff considers this project will have no adverse effect upon community facilities. Staff considers this
criterion met.
(2) The character of the area affected, as defined by the purpose or purposes of the zoning district
within which the project is located, and specifically stated policies and standards of the municipal
plan.
The purpose of the lakeshore neighborhood district is “to encourage residential use at densities and
setbacks that are compatible with the existing character of the lake shore neighborhoods located in
the vicinity of Bartlett Bay Road and Holmes Road. The district is designed to promote the area's
historic development pattern of smaller lots and minimal setbacks. This district encourages the
conversion of seasonal homes to year round residences.” The municipal plan includes a number of
policy statements in the form of Goals, Objectives and Strategies, though those specific to streams
and wetlands do not pertain to this location. Standards are contained in the Land Development
Regulations. Staff considers will be addressed when other comments in this document are addressed.
(3) Traffic on roads and highways in the vicinity.
Staff considers this project will have no adverse effect on traffic on roads and highways in the vicinity.
Staff considers this criterion met.
(4) Bylaws and ordinances then in effect.
Staff considers this criterion will be addressed when other comments in this document are addressed.
(5) Utilization of renewable energy resources.
This project will not affect renewable energy resources. Staff considers this criterion met.
RECOMMENDATION
As the Board is aware, Staff anticipates draft Land Development Regulations to become effective as early
as November 11. The draft Land Development Regulations significantly alter the allowable encroachments
into stream buffers. As today, encroachment within 50-ft of a stream are prohibited except for a small
number of exceptions. As drafted, the LDR would prohibit this project from occurring at all by removing
the exemption potentially applicable to this project, “to the extent directly necessitated for the
construction or safe operation of a permitted or conditional use on the same property.” This application
is subject to the current Land Development Regulations.
The Board must ultimately decide whether to close (and deny) the application or continue the hearing to
allow the applicant further opportunity to address deficiencies discussed herein.
#MS-21-04
Staff Comments
14
Respectfully submitted,
Marla Keene, Development Review Planner