D-7. Fawn Hill: Approve Maintenance Agreement with Riley Purgatory Bluff Creek Watershed District for Storm Water Pond Maintenance Y
Ilk • CITY OF ClIANHASSEN
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Chanhassen isa Community for Life-Providing for Today and Planning for Tomorrow
# II AS
MEMORANDUM
TO: Todd Gerhardt, City Manager J�
FROM: Paul Oehme, Director of Public Works/City Engineer ineer /
DATE: September 25, 2017
SUBJ: Fawn Hill: Approve Maintenance Agreement with the Riley Purgatory Bluff Creek
Watershed District for Stormwater Pond Maintenance
PROPOSED MOTION
"Approve Maintenance Agreement with the Riley Purgatory Bluff Creek Watershed District
(RPBCWD) for Stormwater Pond Maintenance."
City Council approval requires a simple majority vote of the City Council present.
BACKGROUND
The City Council approved the original development contract for Fawn Hill on August 28, 2017.
DISCUSSION
RPBCWD Rules require applicants to ensure maintenance. The City is not the "permit applicant"
for Fawn Hill but will be responsible for future maintenance of the stormwater pond being
constructed with the development. The City is acting on behalf of collaboration and partnership. If
the City chooses not to sign a Maintenance Agreement, the developer may not receive their permit
from the Watershed District.
Stormwater maintenance is a required part of the City's Stormwater Management Plan and the MS4
permit.
The City attorney has reviewed the agreement.
Attachment: Maintenance Agreement
g:\eng\projects\f-j\fawn hill\communication\092517 cc bkgd maintenance agreement.doc
PH 952.227.1100• www.ci.chanhassen.mn.us• FX 952.227.1110
7700 MARKET BOULEVARD • PO BOX 147 • CHANHASSEN • MINNESOTA 55317
MAINTENANCE AGREEMENT
Between the Riley-Purgatory-Bluff Creek Watershed District and
City of Chanhassen, MN
This Maintenance Agreement (Agreement) is made by and between the Riley-
Purgatory-Bluff Creek Watershed District, a watershed district with purposes and
powers set forth at Minnesota Statutes chapters 103B and 103D (RPBCWD), and City of
Chanhassen, a statutory city and body corporate and politic of the State of Minnesota.
Recitals and Statement of Purpose
WHEREAS pursuant to Minnesota Statutes sections 103D.341 and .345, the
RPBCWD has adopted and implements the Wetland and Creek Buffers Rule, and the
Stormwater Management Rule;
WHEREAS under the Wetland and Creek Buffers Rule, certain land development
activity triggers the requirement that the landowner record a declaration establishing
the landowner's perpetual obligation to protect undisturbed buffer adjacent to a creek
or wetland;
WHEREAS under the Stormwater Management Rule, certain land development
activity triggers the requirement that the landowner record a declaration establishing
the landowner's perpetual obligation to inspect and maintain stormwater-management
facilities;
WHEREAS in each case, a public landowner, as an alternative to a recorded
instrument, may meet the maintenance requirement by documenting its obligations in
an unrecorded written agreement with the RPBCWD;
WHEREAS in accordance with the RPBCWD rules, the City's perpetual
obligation to maintain wetland and creek buffer within public property, and the
stormwater facilities must be memorialized in a maintenance agreement specifying
requirements and restrictions;
WHEREAS City and the RPBCWD execute this Agreement and concur that it is
binding and rests on mutual valuable consideration;
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THEREFORE City and RPBCWD agree as follows that City, at its cost, will
inspect and maintain the wetland and creek buffer within public property, and the
stormwater facilities in perpetuity for the Fawn Hill development:
1. BUFFER AREAS
a. Buffer vegetation must not be cultivated, cropped, pastured, mowed,
fertilized, subject to the placement of mulch or yard waste, or
otherwise disturbed, except for periodic cutting or burning that
promotes the health of the buffer, actions to address disease or
invasive species, mowing for purposes of public safety, temporary
disturbance for placement or repair of buried utilities, or other actions
to maintain or improve buffer quality and performance, each as
approved by the District in advance in writing or when implemented
pursuant to a written maintenance plan approved by the District.
b. Diseased, noxious, invasive or otherwise hazardous trees or vegetation
may be selectively removed from buffer areas and trees may be
selectively pruned to maintain health.
c. Pesticides and herbicides may be used in accordance with Minnesota
Department of Agriculture rules and guidelines.
d. No fill, debris or other material will be placed within a buffer.
e. No structure or impervious cover (hard surface) may be created within
a buffer area.
f. Permanent wetland buffer markers will be maintained. Language shall
indicate the purpose of the buffer, restrictions, and the name and
phone number of the Riley-Purgatory-Bluff Creek Watershed District.
2. STORMWATER FACILITIES
a. Stormwater retention basin. Stormwater retention basin must be inspected
at least once a year to determine if the basin's retention and treatment
characteristics are adequate and continue to perform per design. Culverts
and outfall structures must be inspected at least annually and kept clear of
any obstructions or sediment accumulation. Sediment accumulation must be
measured by a method accurate to within one vertical foot. A storage
treatment basin will be considered inadequate if sediment has decreased the
wet storage volume by 50 percent of its original design volume. Based on this
inspection, if the stormwater basin is identified for sediment cleanout, the
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basin will be restored to its original design contours and vegetation in
disturbed areas restored within one year of the inspection date.
b. Infiltration basin and filtration bench. Facilities will be inspected annually
to ensure continued live storage capacity at or above the design volume.
Invasive vegetation, excess sediment and debris will be removed as needed
and healthy plant growth will be maintained to ensure that the facilities
continue to perform per design.
C. Vegetated swales. Vegetated swales will remain free from mowing or other
vegetative disturbance, fertilizer application, yard or other waste disposal, the
placement of structures or any other alteration that impedes the function of
the vegetated swale.
3. Reporting. City will submit to the RPBCWD annually a brief written report that
describes stormwater facility maintenance activities performed under this
declaration, including dates, locations of inspections and the maintenance
activities performed.
4. Property Transfer. If City conveys into private ownership a fee interest in the
property that is the subject of this Agreement, it shall require as a condition of
sale, and enforce: (a) that the purchaser record a declaration on the property
incorporating the maintenance requirements of this Agreement; and (b) that
recordation occur either before any other encumbrance is recorded on the
property or, if after, only as accompanied by a subordination and consent
executed by the encumbrance holder ensuring that the declaration will run with
the land in perpetuity. If City conveys into public ownership a fee interest in any
property that has become subject to this Agreement, it shall require as a
condition of the purchase and sale agreement that the purchaser accept an
assignment of all obligations vested under this Agreement.
5. This Agreement may be amended only in a writing signed by the parties.
6. The recitals are incorporated as a part of this Agreement.
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IN WITNESS WHEREOF, the parties hereto have executed this Agreement.
RILEY-PURGATORY-BLUFF CREEK WATERSHED DISTRICT
By Date:
President, Board of Managers
City of Chanhassen
By: Date:
Its Mayor
By: Date:
Its City Manager
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