3.0. SR 04-24-1993
.
.
.
774-6021 MAIER STEWART ASSOC.
124 P02
APR 21'93 15:11
CONSULTING ENGINEERS
Maier Stewart & Associates Inc.
April 21, 1993
File: 230-161-80
Honorable Mayor and City Council
City of Elk River
P.O. Box 490
13065 Orono Parkway
Elk River, MN 55330
RE: COMPREHENSIVE STORM DRAINAGE PLAN
Dear Council Members:
As you are aware, one of the issues for discussion at Saturday's workshop is the Comprehensive
Storm Drainage Plan. As backup information, attached is a copy of the Draft Stormwater Policy
recommendations that were presented. to the City Council in February.
On Saturday, we will be prepared to discuss specifically how these policies affect the design of
a Comprehensive Storm Drainage Plan utilizing the George Deschenes and Earl Hohel drainage
area as an example. We will have maps available to discuss the flow of drainage in this area
upon ultimate development. We will discuss the sizing and locations of holding ponds and the
size of culverts and drainage pipes to oonvey drainage in this area. to the river.
Based on our discussion on Saturday and any direction given by the City Council, we will then
proceed to complete the draft of the entire Comprehensive Drainage Study to be presented to the
Council at a later date for their review.
Both Mr. Deschenes and Mr. Hohel have been notified that this item will be discussed first
starting at 8:00 a.m. on Saturday, April 24, at City Hall.
Sincerely,
MAIER STEWART &. ASSOCIATES, INC.
x;;;y~
Terry J. Maurer, P.E.
TIM:tp
Hil-2102.apr
1959 SLOAN PLACE. SUITE 200. ST. PAUL, MINNESOTA 55117 812-774-$)21
9800 SHELARO PARKWAV, SUITE 102, MINNEAPOLIS, MINNESOTA 55441 612-546-0432 . Equal Oppol1unl1y Employer
.
.
.
774-6021 MRIER STEWRRT RSSOC.
124 P03
RPR 21'93 15:11
CONSULTING ENGINEERS
Maier Stewart & Associates Inc.
February 24, 1993
File: 23()"161-80
M:r. Pat K1aers, Administrator
City of Elk River
720 DocIge Avenue NW
Elk River, MN 55330
RE: DRAFT - STORM WATER. POllCY RECOMMENDATIONS
Dear Mr. Klaers:
Enclosed is a draft copy of recommendations for City storm water policy. Please review this
with your staff and return your comments to me. If you have any questions or need additional
infonnation, please call.
Sincerely,
MAIER STEWART & ASSOCIATES, INC.
.-3~ 11!P~
SuSan J. McDermott, P .E.
SJM:tp
Enclosure
161.25Q1.fcb
1959 SLOAN PLACE. SUITE 200. Sf. PAUL. MINNESOTA 5$117 e12.n~
9800 SHELARO PARKWAY, SUITE 102. MINNEAPOLIS. MINNESOTA 55441 612.54&0432 · Equal OpFlOnunity Employer
774 6021 MRIER STEWRRT RSSOC.
124 P04
RPR 21'93 15:12
.
February 23, 1993
FUe: 230-161-80
DRAFT
~'~ :
Honorable Mayor and City Council
City of Elk River
720 Dodge Avenue NW
Elk River, MN 55330
RE: STORM WATER MASTER pLAN - POlley RECOM:MENDATlONS
Dear Council Members:
un'RODUCTION
.
The City of Elk River cuuently has no written policies regarding stonn water management
creating difficulty for City st2ff and council members in the review of proposed development.
The council has authorized the first stage in preparation of a Storm Water Management Plan.
This stage will propose various policies for City consideration.
'.. :.,
Providing adequate storm. drainage facilities is an important requirement in the development
of any municipality. As an area develops from rural to urban, culvert and drainageways
which were adequate for rural runoff can beCome overloaded and flood, and property damage
can occur. The function of a stonn drainage system is to minimize economic loss and
inconvenience due to this periodic flooding of streets, basements and other low lying areas.
The desired goal to reach is when storm flooding damage, plus the cost of storm sewer
installation, reaches a minimum. Storm drainage facilities can also reduce inconveniences and
hazards caused by flooding.
Frequently, the downstream area of a drainage basin develops earlier than the remainder of
the basin. 'When this happens, drainage facilities that are installed as part of the early
development may be sized solely for the development occurring without consideration of the
development of the remainder of the basin. A storm drainage master plan considers the entire
dIainage basin and avoids costly erron, such as replacement of inadequate stonn sewer pipe
in developed areas.
'..
If a storm drainage master plan is implemented, planning and construction of required
facilities is established in the early development stages of a drainage basin. Required storm
sewer piping and ponding areas can be easily incorporated into a developer's plan. Regional
ponding areas can be planned, land can be obtained, and possibly integrated into a City park.
The cost of acquiring drainage easements will be low when the land is still rural compared to
its cost after development of the area has increased the land value.
.
.
.
774-6021 MAIER STEWART ASSOC.
124 P05
APR 21'93 15:12
Honorable Mayor and City Council
February 23, 1993
Page Two
1. Authoonr
The City of Elk River, by City Council motion at their December 21, 1992 meeting,
directed Maier Stewart & Associates, InC., to begin development of a Storm D~age
Master Plan by recommending various policy alternatives for the City to consider.
2. Scope
This stage of the Stann Water Master Plan proposes methods of dealing with both
quantity and quality of run-off for both residential and commercial development. In
developing the recommendations herein, existing policies for various metropolitan area
communities and watershed districts were utilized, including Valley Branch and Rice
Creek Watershed Districts and the cities of Roseville, Mahtomedi, and Centerville.
Also, included as an Appendix, is a model ordinance issued by the Metropolitan Council
to assist local governments in the seven county Metropolitan Area. in implementing a
policy to reduce nonpoint source pollution. Although Elk River is outside of the
Metropolitan Council'sjurlsdiction, following the Metropolitan Council's policies would
be prudent from a long-range planning stand point.
WATER QUANTITY
The following policy recommendations regarding water quantity will address natural surface
and groundwater storage and retention systems, as well as flooding concerns.
1. Establish tOO-year flood levels based on critical stann events.
2. Prohibit encroachment that will reduce the capacity of floodways and allow only
structures in the flood fringe that have been flood-proofed or that will not receive
extensive damage. The Floodplain Management Ordinance addresses this policy.
3. Preserve the retention Qpacities of the present drainage systems.
4. Discourage any alteration of wetlands. Allow alteration only if it can be accomplished
within the regulations of state and federal agencies.
5. Regional detention areas, as opposed to individual on-site detention, shall be used to
reduce flooding and to control discharge rates.
6. Major stormwater facilities (e.g., regional detention pond) shall be designed for the 100-
year storm.
.
.
.
774-6021 MAIER STEWART ASSOC.
124 P06
APR 21' 93 15: 13
Honorable Mayor and City Council
February 23, 1993
Page Three
7. Emergency overflows or outlets to City drainage systems shall be provided to any area .
cunently without an overflow or outlet.
8. All minor drainage system (e.g., streets, swales, and storm sewers) analyses and design
shall be based on the S-year rainfall event for residential areas and the lo-year event for
commercial areas.
9. All hydrological studies and drainage desi&n shall be based on the ultimate development
of the entire tributary drainage area.
10. AIl developments shall provide land, funding, or a combination of both for developing
regional sites.
WATER QUALITY
The policy recommendations pertaining to water quality are intended to identify and plan for
means to effectively protect and improve surface water quality, including the preventing
erosion of soil into surface water systems. These policies would also assist in establishing
more uniform local policies and official controls for surface and groundwater management.
1. Treat and/or control runoff to enhance water quality in order to reverse the upward
trends in pollutants, especially nutrient and sediment loads.
2. Develop and implement a community education program relating to preserving water
quality.
3. All construction plans developed for the improvement of water quality shall inc1~de a
detailed plan for maintenance access and a maintenance plan.
4. Wetlands and regional detention areas shall be utilized whenever possible to remove
sediment and nutrients from runoff.
s. The Minnesota Department of Natural Resources and the U.S. Army Corps of Engineers
have regulatory authority relating to waters and wetlands identified on their respective
inventories.
6. The City is responsible for establishing and implementing a permitting program for all
activities relating to drainage, wetlands, erosion control, and water resources
management.
7. All erosion and sediment control measures (e.g., silt fencing) specified in the erosion
.control plan must be installed prior to commencing grading.
774-6021 MAIER STEWART ASSOC.
124 P07
APR 21'93 15:13
e;
Honorable Mayor and City Council
February 23, 1993
Page Four
8. Temporary sediment basins shall be constructed in areas of new development to prevent
sediment from leaving the construction site. Detention basins may be used for temporary
sediment retention during the construction phase. The design criteria should provide
permanent storage volume for sediment or the removal of sediment to restore the
required detention volume.
Detention areas intended to pennanently trap sediments and remove nutrients from the
water shall provide excess storage beyond the lOO-year flood volumes to allQw for
sediment accumulation and a normal pool elevation to exist.
Sedimentation basins shall be capable of removing sediment particles of 0.02 mm
diameter and larger for the average flow of the lo.year, 6-hour storm. The required
surface area should be l,250 times the flow in cubic feet per second. Four feet of
average depth should be available. Sediment basins shall maintain a general length to
width ratio, less than 15 and greater than 10, to be constructed without baffles. Basins
with a length to width ratio as low as 5 are acceptable with an inlet baffle.
.
9. Grading areas shall be protected from runoff to reduce erosion.
10. Site access roads shall be graded or otherwise protected with silt fence, diversion
channels or ditches, and pipes to prevent sediment from exiting the site via the access
road. PrimaI)' site access roads shall be surfaced with crushed rock and extend for a
distance of 100 feet beginning at existing paved surface.
11. The City shall maintain a street sweeping program to minimize sediment entering the
drainage system.
12. Establishment of temporary and permanent vegetation shall be required to minimize the
time that a graded area remains in an exposed condition. For example, temporary
vegetation should be established within 14 days of final grading. Permanent vegetation
should be established on sites that will have no construction activity for one year.
13. Erosion control plans shall be required for all land disturbance activity. The plans shall
be consistent with the MPCA's Preteeti", Water Duality in Urban Areas.
14. Existing stonn drain inlets and conveyance systems shall be adequately protected frem
sedimentation.
. 15. Natural vegetation shall be preserved to the greatest practical extent.
16. The use of grassed waterways shall be encouraged wherever practical to maximize
infiltration and trap pollutants. Grass-lined swales shall be designed to non-erosive
velocities (maximum 2 feet/second) and non-turbulent hydraulic conditions.
774-6021 MAIER STEWART ASSOC. 124 P08
APR 21" 93 15: 14
.
Honorable Mayor and City Council
Febnwy 23, 1993
Page Five
17. The City should adopt design standards for reducing contaminant loads from surl'ace
runoff such as the -best management practices- BMPs outlined in the MPCA publication
Protectinl Water OuaIi~ in Urban Areas. The model ordinance included in the
Appendix suggests this publication be adopted by local government as a design standard
for stonn water ponds. Other acceptable criteria are available from the National Urban
Runoff Program (NURP) and in the Ram~y County Erosion and Sediment Control
Handbook.
CONCLUSION
The City should adopt policies for both water quality and quantity for storm water
management. This could be done through an addition to existing City Design Standards, a city
ordinance or a combination of both. .
The next phase in preparing the Stonn Water Master Plan is an overall stann sewer design
for urbanized areas of the city.
. If you have any questions or require additional information, please call me at 774-6021.
Sincerely,
MAIER STEWART & ASSOCIATES, INC.
Susan J. McDermott, P .E.
SJM:tp
AtQchments
.
774-6021 MAIER STEWART ASSOC.
.
APPENDIX
.
.
124 P09
APR 21' 93 15: 14
774-6021 MAIER STEWART ASSOC.
124 P10
APR 21' 93 15: 14
, ,
.
ORDlNANCE NO.
STORM 'VATER MANAGEMENT OJtOTNANCE
AN ORDINANCE PROMOTING ruE HEALTH, SAFE'N AND
GENERAL WELFARE OF TIlE CITIZENS OF
MINNESOTA. BY MiENDING THE ZONING ORDINANCE.
ADOPTING NEW SEcnONS REQUIRING STORM WATER
MANAGEMENT PRACIlCES.
1. STATUTORY AUTHORIZATION
This ordinance is adopted pursuant to Minnesota Statutes Section (462.351 Cor cities .lInl towns.
3Y.&.21 for counties having a population of less than 300,000 according to the 1950 Cedcl ill census]
( 1990).
2. FINDINGS
.
The [City, County, Town} of hereby finds that uncontrolled and inadequately plillllled use
of wctlnnds, woodlands, natural habitat areas, areas subject to soil erosion and areas cc lllhlining
restrictiv\: ~oils adversely affects the public health, safety and general welfare by impa~liJlg water
quality <Iud contributing to other environmental problems, creating nuisances, impail iug other
beneficial uses or environmental resource$ and hindering the ability of the [City, County. Towill of
to provide adequate water, sewage, flood control. and other community sel vices. In
addition. extraordinary public: expenditures may be required Cor the protection of pel~()nS and
property in sueh areas and in areas which may be affected by unplsJ:J,ned land usage.
3. PURPOSE
lllC.~ purpose of this ordinance is to promote, preserve and enhance the natural resources within the
(City. COUllty, Town] of and protect them from adverse effects occasioned by p(l(}rly sited
development or incompatible activities by regulating land disturbing or development acti....ities th.ll
would huv~ an adverse and potentially irreversible impact on water quality and unique and Cmgile
environmentally sensitive land; by minimizing conflicts and encouraging compatibility between land
disturbing and development activities and water quality and environmentally sensitive lands; and hy
requiring detailed review standards and procedures for land disturbing or development activities
pmpo$\:d for such areas, thereby achieving a balance between urban growth and develo)llllcnt and
protection of water quality and natural areas.
4. DEFlNmONS
For the purposes of this ordinanu, the following terms, phrases. words, and their derivaliv~ shall
have the: meanin, stated below. When not inconsistent with the context. words used in the present
tense indlldc the future tense, words in the plural number include the singular number, cmd wnnJs
in the singular number include the plural number. The word -'shan- is always mandatory ilnd nlll
merely dir~ctive.
.
4.1
op-plicant. Any person who wishes to obtain a building permit, zoning or suhdivisiun
al1proval.
4.2 CIl{ltrol measure. A practice or combination of practices to control erosion and Hllcnd:lnl
pullution.
4.J D~tention facility. A permanent natural or man-made structure, including wetland~. t'(u the
_ _ __ __ _a_.____ _I: ...__f'r' ....L:_L ___e_=... ... _________ ___1 _, __._.__
774-6021 MAIER STEWART ASSOC.
124 Pll
APR 21' 93 15: 15
.
4.4
Aood frine.c. The portiOD or ~he floodplain outside of the noodway:.
4.5 floodplain. The areas adjoining a watercourse or water basin that have been or may be
covered by a regional flood..
4.6 F1oodwav. The chaonel of the watercourse. the bed of water basins, and those portions or
the adjoining floodplains that are reasonably required to eany and discharlc floodwater and
provide water storage during a regional flood.
4.7 Hvdric soils. Soils that are saturated, flooded. or ponded long enough during the growing
season to develop anaerobic: conditions in lhe upper part.
4.8 Hvdrophvtic ve~etatiott. Macrophytic plant life growing in water. soil or aD a sub~trate that
is at least periodically deficient in oxygen as a result of excessive water contenL
4.9 Land disturb;"\! or dcyelooment activities. Any change of the laed surface including removinl
vegetative cover. excavating. filling, grading. and the construction of any structure.
4.10 Pe~Qn. Any individual, firm, corporation. partnenhip, franchisee, association or
governmental entity.
4.11 Public walen. Waters of the state as defined in Minnesota Statula, section 1030.005,
subdivision 15.
.
4.12 Re2ional flood. A flood that is representative of large floods known to have occurred
generally in the stalc and reasonably characteristic of wbat can be expected to occur on an
average frequency in tbe magnitude of a lOO-year recurrence intervaL
4.13 Retention facititv. A permanent natural or man made structure that provides Cor lhe storage
or storm water runoff by means of a permanent pool of water.
4.14 Sediment. Solid matter carried by water, sewage, or other liquids.
4.1 S Structure. Anything manuCactured, constructed or erected which is normally attached to or
positioned on land, including portable structures, earthen structures, roads, p.rkin~ lots. and
paved storage areas.
4.16 Wet)ands. Lands transitional between terrestrial and aquatic systems where tbe water table
is usually at or near the surCace or the land is covered by shallow water. For purposes or this
definition, wetlands must have the following three attnDutes:
8) Have a predominance of hydric: soils;
b) Are inundated or saturaled by surface or ground water at a Crequency Bnd duration
sufficient to support II prewtence or hydrophytic vegetatioD typically adapted Cor life
in saturated soil conditions; and
.
c)
Under normal circumstances support a prevalence of such vegetation.
[COMMENTARY: }.fany of the above de[lJ1itions are derived from stQt~ law. A local
government should insure ,hat the de{rnitions fJre also consistent wirh defrnitions ilf the local
zon.ing code.}
.
5.1
5.2
.
774-6021 MAIER STEWART ASSOC.
124 P12
APR 21'93 15:15
S. SCOPE AND EFFECr
~12Plicabi1itv. Every applicant Coor a building permit, subdivision approval, oro a permittn alluw
l:.md disturbing activities must submit a storm water management plan to the Il'hmning
tl~partment. department of community development, zoning administrator). No building
I~rmit, subdivision approval, or permit to allow land disturbing activities shall be isslJ~d until
approval of the storm water management plan or a waiver of the approval requirement bas
been obtained in strict conformance with the provisions or this ordinance. The pro1.'isions or
section 9 of this ordinance apply to all land, public or private, located within the. (Cily. Town,
County] of
Exemptions. The provisions of this ordinance do not apply to:
a) Any part of a subdivision if a plat for the subdivision has been approved by lh~ [City
Council, County Board, Town Board] on or before the effective date or lhis
ordinance;
b) Any land disturbing activity for which plans have been approved by the watershed
management organization within six months prior to the effective date uf Ihis
ordinance;
c) A lot for which a building permit has been approved on or before the effective: dale
of this ordinance;
d)
Installation of fence, sign. telephone, and electric poles and other kinds or p<lsls or
poles; or
c) Emergency work to protect life, limb, or properly.
5.3 W"jver. The [City Council, Town Board, County Board], upon recommendatioll of the
Planning Commission, may waive any requirement of this ordinance upon making a I1nding
thill compliance wilh the requirement will involve an unnecessary hardship and the w:livcr oC
such requirement will not adversely affect the standards and requirements set Corth in Section
6. The [City Council, Town Board, County Board] may require as a condition of the waiv~r.
liuc.:h dedication or construction, or agreement to dedicate or construct as may be necessary
to adequately meet said standards and requirements.
.
6. STORM WATER MANAGEMENT PlAN
APPROVAL PROCEDURES
6.1
a.uplication. A written application for storm water management plan approval, along with
the proposed stonn water management plan, shall be rued witb the [planning del)artment,
department of community development. zoning administrator] and shall include a statement
imJicating the grounds upon which the approval is requested, that the proposed use: is
permitted by right or as an exception in the underlying zoning district, and adequate e\.idence
shuwing that the proposed use will conform to the standards set forth in this ordinance. Prior
to applying for approval of a storm water management plan, an applicant may have lhe.: storm
w:tlc:r management plans reviewed by the appropriate depanmenlJ oCthe [city, town. l:ounly).
T\.\o\) sets of clearly legible blue or black lined copies or drawings and required inforlllalion
shull be submitted to the [planning department, department or community devdupmcnt,
~()l1ing administrator] and shall be accompanied by a receipt from the
{governmental unh's chier financial officer] evidencing the payment of all required fees for.
pi ocessing and approval as set Corth in Section 7.s, and a bond when required by S\.:l:lion 7.4
.
6.2
.
.
774-6021 MAIER STEWART ASSOC.
124 P13
APR 21' 93 15: 16
in the amount to be calculated in accordance with that section. Drawings shall be prepared
to a scale appropriate to the site of the project and suitable Cor the review to be performed.
At . minimum the scale shall be 1 inch equals 100 feet.
Storm water "manaqement plan. At 8 minimum, the storm water management plan shall
contain the following information.
a) &istinsz site map. A map of existing site conditions showing the site and immediately
adjacent areas, including:
1) The name and address of the applicant, the section, township and r:lnge, north
point. date and scale of drawing and number of sheets;
2) Location of the tract by an insert map at a scale sufficient to clearly identify
the location of the property and giviol such information as the names and
numbers of adjoining roa4s, railroads. utilities, subdivisions. towns and districts
or other landmarks;
3) Existing topography with a contour interval appropriate to the topt'graphy or
the land but in no case having a contour interval greater than 2 rc~t;
4)
A delineation of all streams. rivers, public waters and wetlands localed on and
immediately adjacent to the site, including depth of water. a description of all
vegetation which may be found in the water, a statement of general water
quality and any classification given to the water body or wetlltnu by the
Minnesota Department of Natural Resources, the Minnesota Pollution
Control Agency, and/or the United States Army Corps of Engineers;
S)
Location and dimensions of existing storm water drainage systems and natural
drainage patterns on and immediately adjacent to the site delineating in which
direction and at what rate storm water is conveyed from the site, identifying
the receiving stream, river, public water. or wetland, and setting forth those
areas of the unaltered site where storm water coll~ts;
6)
A description of the soils of the site, including a map indicating Sllil types of
areas to be disturbed as well as a soil report containing inCormatiun on the
suitability of the soils Cor the type of dc::velopment proposed and for the type
of sewage disposal proposed and describing any remedial steps to be taken by ..
the developer to render the soils suitable;
Vegetative cover and clearly delineating any~getatioD proposed ror removal;
and
7)
8)
100 year floodplains. Oood fringes and fioodw8ys.
b) Site construction plan. A sile coMtruclion plan including:
1)
Locations and dimensions of all proposed land disturbing activiLic~ and any
phasing of these aCljo.;ties;
2) Locations and dimensions of all temporary soil or dirt stockpiles:
3) Locations and dimensions of all eonstructions site erosion control measures
necessary to meet the requirements or this ordinance;
.
.
7.1
.
774-6021 MAIER STEWART ASSOC.
124 P14
APR 21' 93 15: 16
4)
Schedule or antidpated starling and completion date or each land tlisturhing
activity including the installation of construction site erosion control U1casura
needed to meet the requirements of this ordinance; and
S)
Provisions fo~ maintenance or the construction site erosion conlrolmcasurcs
during construction.
c:)
Plan or final site conditions. A plan of final site conditions on the: same SCOt I..: as the
existing site map showing the site changes including:
1)
Finished grading shown at contours at the same interval as providcd ahove or
as required to clearly indicate the relationship of proposed changes 10 ~xisting
topography and remaining features;
2)
A landscape plan. drawn to an appropriate scale. including dimensions amI
distances and the location, type, size and description or all proposed landscape
materials which will be added to the site as part or the developmcnt;
3)
A drainage plan of the developed site delineating in which direction and at
what rate storm water will be conveyed from the site and selling forth the
areas of the site where storm waler will be aJJowed to conect;
4)
The proposed size, alignment and intended use olany structures to II(~ ~rcclcd
on the site;
S)
A clear delineation and tabulation of all areas which shall be paved or
surfaced, including a description of the surfacing material to be used; and
6) Any other information pertinent to the particular project which in lhe opinioll
of the applicant is necessary for the review of the project.
7. PLAN REVIEW PROCEDURE
fmccls. Storm water management plans meeting the requirements of Section " shall be
$ubmitted by the [planning department. department of community development. zoning
administrator] to the Planning Commission for review in accordance with the stancJards of
S&.:Ction 8. The Commission shall recommend approval. recommend approval with conditions, .
(u recommend denial of the stonn water management plan. Following Planning Commission
aClion, the stonn water management plan shall be submiued to the [City Council, Town
Board, County Board] at its next available meeting. [City Council, Town Board, COllnty
Onurd) action on the storm water man;tgcment plan must be accomplished within 120 days
fullowing the date the application for approval is filed with the [planning dc:pnrtmenc.
department of community development. zoning administrator].
[COMMENTARY: The process outliMJ in Section 7.1 am be modified to be consistenlltl;tlr the
n:gu/DtOf}' FOCUS of the panicular /ucul government unit For uample. one local gCJL'emmenl
IIIOY have a panicular department ",,"hich reviews land use regulatory malten except the fi/1ll1
decision to approve or deny a land uu plan or permit which is reserved for the gOt/eming body
01 the local government unit A/WIIle'T local governmental unit may provide the dl.'panme/zl
which reviews land use regulatory nlatters with full authority ro rake [utal actioll Oil tile
application. Other local govemmenrs may we a hybrid process where some pemtits (Ire aCtecl
UpOIl by the appropriate regulatory dt!pnrrment while other land use malten are Ilft to llr~
gm"r?ming body for final approval.]
7_2
Duratinn. Aporoval or a plan submittcd under the provisions of this ordinance shall cArlirc
.
7.3
7.4
.
.
774-6021 MRIER STEWRRT RSSOC.
124 P15
RPR 21'93 15:17
one year after the date of approval unless c:onslructioD has commenced in ac:c:onli'Ulce with
the plan. Howc::ver, if prior to 'the expiration or the approval, the applicant makes a written
request to the (planning department, department or community development. zoning
administrator) Cor an extension oC time to commence constNction setting Conh the reasons
ror the requested ertension, the planning department may grant one e%tension of nol greater
than one single year. Receipt of any request ror an extension shall be acknowledged by the
[planning department, department or community development, zoning administrator) within
15 days. The (planning department, department of community development, zoning
administrator) shall make a decision on the extension within 30 days of receipL Any plan may
be revised in the same manner as originally approved.
Conditions. A storm water management plan may be approved subject to compliance with
conditions reasonable and necessary to insure that the requirements contained in tbis
ordinance are met. Such conditions may, among other matters, limit the size, kind or
character of the proposed development, require the construction of structures. drainage
racilities, storage basins and other faciliti~ require replacement of vegetation, establish
required monitoring procedures. stage tbe work over time, require alteration of the site design
to insure buffering. and require the conveyance to the [City, Town, County] of or
other public entity of certain lands or interests therein.
Performance bond. Prior to approval of any storm water management plan, the applicant
shall submit an agreement to construct such required physical improvements, tn dedicate
property or easements, or to comply with such conditions as may have been agreed to. Such
agreement shall be accompanied by a bond to cover the amount of the established ~t of
complying with the agreement. The agreement and bond shall parantee completion and
compliance with conditions within a specific tim.e, which time may be extended in accordance
with Section 7.2.
The adequacy. conditions and acceptability of any agreement and bond shall be determined
by the [City Council, Town Board, County Board) or any omcial or the (City,
Town, County] of as may be designated by resolution of the [Clly
Council, Town Board, County Board].
7.5 Fees.. All applications for storm water management plan approval sbaU be accompanied by
a processing and approval fee or S
8. APPROVAL STANDARDS
8.1 No storm water management plan which Caits to meet the standards contained in this section
shall be approved by the [City Council, Town. Board, County Board].
[COMMENTARY: Sections 8.2 thr;ough 8.16 an an t'ZIImple o/how best mtlNlgemelll practices
for II/mdling storm water runoff and design criterillfor detention ponds ClIII ba included wilhi1I
an ordinancL Additional best maNlgement practicu . and duign aileria am be found in the
MPCA. publication · Protec:ting Water Quality in Urban Areas.. · .
Site dewaterilli. Water pumped from tbe site shall be treated by temporary sedimentation
basins, grit chambers, sand filtets, upfiow chambers, hydro-cycloncs, swirl concentrators or
other appropriate controls as appropriate. Water may not be discharged in a manner that
causes erosion or flooding or the site or receiving channels or a wetland.
8.2
8.3 Waste and materi,] disposal. All waste and unused building materials (including garbage,
debris, cleaning wastes, wastewater. toxic m.aterials or bazardous materials) shalt be properly
disposed of off-site and not allowed to be carried by runoff into a receiving channel or storm
774-6021 MAIER STEWART ASSOC.
124 P16
APR 21'93 15:17
.
8.4
IrackiM. Each site shall have gravel~d roads, access drives and parking areas <<.')1 :\ull1ci~nl
wi..Jth and length to prevent sediment from being tracked onlO public or private ro..cJW3}'S.
Any sediment reaching a public or private road shall be removed by streel tlc.millg (nol
nushing) before the end of each workday.
8.S Orain inlet orotection. All s,torm drain inlets shall be protected during construed,)n until
ennlrol measures are in place with a straw bale, silt fcnce or equivalent barrier meeting
acc~pled design criteria, standards and specifications contained in the MPCA puhliC<ion
.Protecting Water Quality in Urban Areas.-
8.6 Site erosion control. The following criteria (a. through d.) apply only to construction
activities that result in runoff leaving the site.
a) Channelized runorC Cram adjacent areas passing through the site shall hI.: diverted
around disturbed areas. if practical. Otherwise, the channel shall be protected as
described below. Sheetfiow runorf from adjacent areas greater than 10.000 SqUilrC feet
in area shall also be diverted around disturbed areas, unless shown to have resultant
runoff rates or less than 0.5 fL3/sec. across the disturbed area for the one )'Cilr storm.
Diverted runoff shall be conveyed in a manner that will not erode the convcymlce and
receiving channels.
b) All activities on the site shan be conducted in a logical sequence to minimize the area
of bare soil exposed at anyone lime.
.
c) Runoff from the entire disturbed area on the site shall be controUed by meeting either
subsections 1 and 2 or 1 and 3.
I} All disturbed ground left inactive (or fourteen or more days shall be st.lhili~cd by
seeding or sodding (only available prior to September IS) or by lnull.:hing or
covering or other equivalent control measure.
2) For sites with more than ten acres disturbed at one lime. or if a channc1l11 igin<tlcs
in the disturbed area, one or more temporary or permanent sedimentalitlll basins
shall be constructed. Each sedimentation ba5in shall have a surface area of at
least one percent of the area draining to the basin and at Jeast three feet (lC depth
and constructed in accordance with aceepled design specifications. Sedinu:nl shall
be removed to maintain a depth of three reeL The basin discharge rate shall also
be sufficiently low as to not cause erosion along the dischar,e channel or the
receiving water.
3) For sites with less than ten acres disturbed at one time. silt fences, straw bales. or
equivalent control measures shall be placed along aU sideslopc and downslope
sides of the site. If a channel or area of concentrated runoff passes through the
site. silt fences shall be placed along the channel edges to reduce sediment
reaching the channeL The use or silt fences. straw bales, or equivalent control
measures must include a maintenance and inspection schedule.
.
d) Any soil or dirt storage piles containing more than ten cubic yards or maleriul should
not be located with a downslope drainage length of less than 2S feet from the toe of
the pile to a roadway or drainage channel. If remaining for ,more than seven days, they
shall be stabilized by mulching. vegetative cover, larps or other means. Erosion Crom
piles which will be in existence for less than seven days shall be controlled hy placing
straw bales or silt fence barriers around the pile. In-street utility repair or cOllstruclinn
soil or dirt storage piles located 'closer than 25 feet of a roadway or drainage channl.:l
must be covered wilh tarps or suitable alternative control, if exposed for mure than
.
774-6021 MRIER STEWRRT RSSOC.
124 P17
RPR 21' 93 15: 18
seven clays, and the slonndrain inlets must be protected with straw bale or other
appropriate filtering barriers..
Storm water mana,ement criteria for permanent facilities.
a) An applicant shall ins'tall or construct, on or (or the proposed land disturbing or
development activity, all storm water management facilities necessary to manage
increased ruooa so that the twQ.year, ten.year, and tOO-year Slonn peak discharge rates
existing before the proposed development shan not be increased and accelerated
cbannel erosion will not occur as a result of the proposed land disturbing or
development activity. An applicant may also make an in-kind or monetary contribution
to the development and maintenance oC community storm water management (acilities
designed to serve multiple land disturbing and development activities undertaken by one
or more persons, including the applicanL
8.7
b) The applicant shall give consideration to redudng the need Cor slorm water
management facilities by incorporating the use or Datural topography and land cover
such as wetlands. ponds, natural swales and depressions as they e.~ist berore
development to the degree that they can accommodate the additional now of water
without compromising the integrity or quality of the wetland or pond.
c) The following storm water management practices shall be investigated in developing a
storm water management plan in the following descending order of preference:
.
1) Infiltration oC runoff on-site. if suitable soil conditions are available for use;
2) Flow attenuation by use of open vegetated swales and natural depressions;
3) Storm water retention facilities; and
4) Storm water detention facilities.
A combination of successive practices may be used to achieve tbe applicable minimum
control requirements specified in subsection <a> above. Justification shall be provided
by the applicant for the method selected.
8.8 Desirn standards. StOnD water detention (aenities constructed in tho [City, Town, County]
of' shall be designed accardin, to the mast current tcchDology .. rcOected ID the
MPCA publieatioD .Protecting Water Quality in Urban Areas-, aDd shan contaia, at .
minimum, the following design factors:
.
d)
a)
A permanent pond surface area equal to two perceDt of the impervious area draining
to the pond or ODe pera:Dt of the entire area d~iDg to the pond, whichever amount
is greater;
b)
An average pennanent pool depth or Cout to ten feet;
[COMMENTARY:.An iZlterruuive to subsections (a) tlnd (b) would be 10 require that the
volllrM 01 the pemulntnt pool be equ.al to or gretJter than 1M IU/UJD from 0 20.inch
rainfall for the fully developed site.}
c)
d)
A permanent poollength-to-width ratio of 3:1 or greater;
A minimum protect.ive shelf extending ten feet into the permanent pool wilh a slope
of 10:1. beyond which slopes should not exceed 3:1;
774-6021 MAIER STEWART ASSOC.
124 P1S
APR 21' 93 15: 18
.
~) A protective buffer suil' of vegetation surrounding the permanent pool at a minimum
width of one rod (16.5 feel) [this width is consistent with Ihe draft rules develupt:(l by Ill,:
Board of IValet and Soil Resources under the WeIland Consel'Vanoll Aa of 1991 J;
f)
All storm water detention facilities shall have a device to keep oil, grease, am.I other
floatable material from moving downstream as a result of normal operations;
g)
Storm water detention facilities Cor new development must be sufficient to limit peak
nows in each subwatershed to lhose that existed before the development for the 10 year
storm evenL All calculations and hydrologic rnode1slinCormation used in determining
peak nows shall be submitted along with the storm water management plnn;
11)
All storm water detention facilities must have a forcbay to remove co~rsc .grainr.:d
particles prior to discharge into a watercourse or storage basin.
8.9 \Vctlands.
a) Runoff shall not be discharged directly into wetlands without presettJement oC the
runoff.
.
b) A protective burrer strip of natural vegetation at least one rod (16.5. feet) in width shall
surround all wedands. [This width is consistent with ,hI draft rules developed by lite
Board of Waler and Soil Resources under the WeIland COlUel'Yation. A.ct of lY9l.j
c) Wetlands must not be drained or filled, wholly or partially. unless replaced by restoring
or creating wetland areas of at least equal public value. Replacement must he: guided
by the following principles in descending order of priority:
1) Avoiding tbe direct or indirect impact of the activity that may destroy or diminish
the wetland; .
2) Minimizing the impact by limiting the degree or magnitude of the wetl;mcl activity
and its implementation;
3) Rectifying the Impact by repairing, rehabilitating. or restoring the affected wctland
environment;
4) Reducinc or eliminating the impact over time by preservation and JiiaiiiteDance
operations during the liCe of the activity; and
5) Compensadng for the impact by replacing or providing substitute wetland
resources or environments. [Compensation. including the nplac,ment ratio II/Ill
quality of nplacemml should ~ eonsUtenl with the rrquiremtnu Olll/utet/ in 1M
rules which will be adopted by 1M Board 0/ WafII' and Soil Raoruas to impknlDll
the Wetland C011Sel'VllnOn Act of 1991.J
.
8.10 ~leeD slopes. No land disturbin.c or development activities shaD be allowed on slopes of 18
per cent or morc..
8.11 Catch basins. All newly installed and rehabilitated catch basins s~all be provided with a sump
area {or the collection of coarse-.grained material Such basins shall be cleaned when they arc:
half filled with material.
8. 12 Drain leadcrI. All newly construcled and reconstructed buildings will route drain kaders to
pCI vious areBS wherein the runoff can be allowed to innItrate. The flow rate oC W.llcr exiting
774-6021 MAIER STEWART ASSOC.
124 P19
APR 21'93 15:19
.
. the leaders shall be controll~d so no erosion occurs in the pervious areas.
8.13 Inspection and maintenance. All stann water manalement facilities shaD be designed to
minimize the need or maintenancc, to provide access for maintenance purposes and to be
structurally" sound. All stor:m water management facilities shall have a plan of operation and
maintenance that assures continued effective removal of poJlutaDts carried in stonn _ater
runoa. The director of public works, or designated representa~ shaD inspect aU storm
water management facilities during construction, during the first year of operation, and at
least once every fIVe years thereafter. The inspection records wilt be kept on file at the
public works department for a period of 6.yean. It shall be the responsibility of the applicant
10 obtain any necessary easements or other property interests to allow access to the storm
water management Cacilities Cor inspection and maintenance purposes.
.
8.14 ModeJs/methodolol!ies/computations. Hydroloiic models and dcsilJ1 methodologies used Cor
the determination of runoff and analysis of storm water manalement structures shall be
approved by the dlreetor or public works. Plans, specification and computations Cor storm
water management [acilities submitted for review shall be sealed and signed by a registered
proCessional engineer. All computations shall appear Oft the plaos submitted for review,
unless otherwise approved by the director or public works.
8.1S Watershed manaeement plans/Jroundwater m8na~ement plan,. Stann water management
plans shall be consistent with adopted watel$hed management plaus and groundwater
management plans prepared in accordance with Minnesota Statutes section 1038.231 and
103B.255 respectively, and as approved by the Minnesota Board of Water and Soil Resources
in accordance with stale law.
8.16 Easements. If a stonn water management plan involves direction of some or all runoff 0[[ _
of the site, it shall be the responsibility of the applicant to obtain Crom adjacent property
owners any necessary easements or other property interests concerning nowage of water.
9. LAWN FERTILIZER REGULATIONS
.
9.1 Use of imDervious surfaces. No person shall apply fertilizer to or deposit Jf8J\.'i clippings.
leaves, or other \leietative materials on impervious surfaces, or within storm water drainage
systems, natural drainage ways, or within wetland buffer areas.
92 Unfmprovedland areas. Except for driveways, sidewalb, patios, areas ~pied by structures
or areas which have been improved by landscaping, all areas sbaU be COYercd by plants or
vegetative growth.
9.3 Fertilizer contenL Except Cor the first growing seasoD ror newly established turf areas~ no
person shaD apply Uquid fertilizer which contains more than ooe-haIf pcReDt by weight of
phosphorus, or granular fertilizer wbich contaias more lIwl three perceIlt by weight or
phosphorus, unless the smile application is less than or equal to oDe.tenth pound or
phosphorus per one thousand square feeL Annual application amount shaD not exceed onc-
half pound or phosphorus per one thousand square feet of lawn area.
Buffer zone. Fertilizer applications shaU not be made within one rod (16.5 feet) or any
wetland or water resource. [17zis distance is consistelll with the draft tula tIne/oped by ~
Boord of Water and Soil Resources unt:ler the Wedtlnt1 Coruervanon Act of 1991.)
9.4
to. PENALTY
Any person. firm or corporation violating any provision of this ordinance sball be lined nClI less than
....__ .1_11__ ___ _....... ....... rtV.. "'....,f...... 1'1....11..._ r".. ......l. ,.Fr...... .......... .__......... _n'..._...... _'-All ~
.
.
.
774-6021 MAIER STEWART ASSOC.
124 P20
APR 21'93 15:19
.'
deemed c;, IInmiucd on each day during or on which a ~i()laliun occurs or cOD!inucs.
11: OTHER CONTROLS
In the evc:nt or any conDiet between the provisions of Ibis ordinance and the provisioas or an erosion
control or .horel.ad protc:ct.lon ordinance adopted by the [City Council. Town Board. CoulIty Board).,
the more restrictive standard prc:vailL
12. SEVERABILITY
The provisions or this ordinance arc severable.. If any provision of this ordinance or the application
thereof to any person or circumstance is held invalid, such invalidity shall Dot atrect other provisions
or applications of this ordinance wbich ean be given eaec:t without the invalid provision or application
13. EFFECTIVE DATE
This ordinance shall be cfIective the
day of
" 199_"
.
.
.
774-6021 MRIER STEWRRT RSSOC.
RPR 21'93 15:20
124 P21
lIIULlOCRAPIIY FOR MODEL STOtu.1 WATER MANAGEMENT ORDINANCE
~ tinnCSQla Pollution Control Agency, Division of Water Quality, P(ptcctinr Water Quality in Urhnn
Arcns: nest M8!"1a~ement Practices for Minnesota (1989).
Wisconsin Department or Nalural RCIOurccs, ~odel Construction Site ErosioD Control Ordinance,.
Wisconsin Construction Site Best Mana~ement Practice Handbook (198'7).
Metropolitan Council, Envi{Onmental Protection: Mmel Ordinances ror Use by Local Ocwc.:mmcnlS
(1977). .
Mauhcws, Municipal Ordinances. II 5209, 52.10 (Cumulative Supplement, 2d Ed.).