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City of

Whitewater

Erosion Control and

Stormwater Management Requirements

City of Whitewater

Erosion Control and Stormwater Management Requirements

Section 1 – Technical Standards

1.

TABLE OF CONTENTS

Page

No.

or

Following

SECTION 1 – TECHNICAL STANDARDS

1.01

Technical Standards and

References

........................................................

1-1

1.02

Precipitation Depth, Distribution and

Average

...........................................

1-1

1.03

Design

Methods

.........................................................................................

1-2

1.04

Design

Criteria

...........................................................................................

1-3

SECTION 2 – PERFORMANCE STANDARDS

2.01

Erosion Control Standards.........................................................................

2-1

2.02

Stormwater Management

Standards

.........................................................

2-3

SECTION 3 – GENERAL CONSIDERATIONS

3.01 Stormwater Management Considerations.................................................. 3-1

SECTION 4 – SUBMITTAL REQUIREMENTS

4.01

Erosion and Sediment Control

Plan

...........................................................

4-1

4.02

Stormwater Plan ........................................................................................

4-5

SECTION 5 – DEFINITIONS

SECTION 6 – FORMS

Stormwater Management Permit Application

Stormwater Management Permit

Construction Site Erosion Control Permit Application

Construction Site Erosion Control Permit

Sample Maintenance Agreement

Sample Financial Guarantee

APPENDICES

APPENDIX A - STORMWATER MANAGEMENT ORDINANCE

APPENDIX B - CONSTRUCTION SITE EROSION CONTROL ORDINANCE

APPENDIX C - WET DETENTION BASIN TECHNICAL STANDARD

City of Whitewater

Erosion Control and Stormwater Management Requirements

Section 1 – Technical Standards

1.

SECTION

1

TECHNICAL

STANDARDS

1.01 TECHNICAL STANDARDS AND REFERENCES

A. Erosion Control and Stormwater Management Technical Standards

All drainage facilities and practices required to comply with the Erosion Control and

Stormwater Management Ordinances shall incorporate technical standards and design

methods specified in this document, maintained and periodically updated by the Director of

Public Works. Where not superceded by stricter requirements in this document, the

following standards are also incorporated by reference:

1. Applicable design criteria, standards, and specifications identified in the

Wisconsin Construction Site Best Management Practice Handbook,

Wisconsin Department of Natural Resources (DNR) Pub. WR-222, November

1993 Revision.

2. Other design guidance and technical standards identified or developed by the

DNR under subchapter V of chapter NR 151, Wisconsin. Administrative

Code.

3. DNR is required by recent rule revisions to develop technical standards to

provide guidance for measurement and evaluation of this performance

standard. Measurement and evaluation of this performance standard shall

be based on guidance published by the Department of Natural Resources.

Until such guidance is published, total suspended solids removal shall be

achieved to the maximum extent practical through implementation of

approved BMP’s.

1.02 PRECIPITATION DEPTH, DISTRIBUTION AND AVERAGES

A. Precipitation Depths

The following references may be used as a source for design rainfall depths:

1. Rainfall Frequency Atlas of the United States, US Department of Commerce,

Weather Bureau Technical Paper No. 40, May 1961.

2. Huff, Floyd A., and Angel, James R., Rainfall Frequency Atlas of the Midwest,

Midwestern Climate Center, Bulletin 71, 1992.

City of Whitewater

Erosion Control and Stormwater Management Requirements

Section 1 – Technical Standards

2.

B. Precipitation Distribution

1. Where Technical Paper No. 40 rainfall depths are used, they shall be used in

conjunction with the SCS Type II rainfall distribution for a 24-hour storm

duration. Technical Paper No. 40 rainfall depths shall not be allowed with

Huff rainfall distributions.

2. Where Bulletin 71 rainfall depths are used, they shall be used in conjunction

with the appropriate quartile Huff rainfall distribution for the storm duration

producing the highest peak discharge.

C. Average Annual Rainfall

1. For applications requiring use of average annual rainfall, recorded City

of

Madison depths for March 12 through December 2, 1981, shall be

used.

1.03 DESIGN METHODS

A. Stormwater Runoff Calculations

1. For design of volume-dependent practices (detention basins, retention

basins, infiltration systems, etc.), a hydrograph-producing method hydrologic

model shall be developed. The following computer programs shall be

allowed:

a. TR-55

b. TR-20

c. HEC-1

d. HEC-HMS

e. Other computer programs as allowed by the Director of Public Works

2. The Rational Method may be used to calculate peak discharges for tributary

areas less than 20 acres for purposes of conveyance system design.

3. Estimation of Required Storage Volume

a. Final detention basin sizing shall be based on hydrograph routing

through the basin with the proposed outlet structure.

b. The Soil Conservation Service TR-55 Approximate Method may be

utilized to calculate the required storage volume. This may be used

for developments with watershed areas of less than 25 acres which do

City of Whitewater

Erosion Control and Stormwater Management Requirements

Section 1 – Technical Standards

3.

not involve significant off-site drainage that must be passed through

the detention basin or routing of stormwater runoff through a series of

detention basins. Soil Conservation Service Type II rainfall shall be

utilized to estimate storage volume and peak inflow requirements.

4. Stormwater Conveyance System Design

a. Storm Sewers shall be designed in accordance with procedures

described in Procedures 13-25-35 through 13-25-45 of the Wisconsin

Department of Transportation (WisDOT) Facilities Design Manual

(FDM).

b. Ditches shall be designed in accordance with procedures described in

Procedures 13-30-5 through 13-30-10 of the WisDOT FDM.

c. Cross Culverts shall be designed in accordance with procedures

described in Procedure 13-15-10 of the WisDOT FDM.

1.04 DESIGN CRITERIA

A. Wet Detention Basins

Design in accordance with the Wet Detention Basin Conservation Practice Standard

(DNR), Section V.A.1, 2, 4-11 (Appendix A).

B. Dry Detention Basins

1. Minimum grades for the bottom of the basin shall be 2 percent unless

under drain is installed. If under drains are installed, the minimum grade shall

be 0.5 percent.

2. Basin side slopes shall not be steeper than 4:1 or flatter than 10:1.

3. Dry detention basins shall be designed to drain completely within 24 hours

after the storm event.

4. Forebays shall be used to the maximum extent practical to prevent

concentrated flow from entering the basin and allow sediment to settle prior

to entering the basin.

a. Forebay area should be 10 to 25 percent of the basin’s surface area.

b. Length to width ratio shall be at least 2:1.

City of Whitewater

Erosion Control and Stormwater Management Requirements

Section 1 – Technical Standards

4.

c. The forebay shall be located opposite of the basin’s outlet to increase

detention time.

5. The basin shall be designed with an emergency spillway designed to convey

the 100-year peak discharge entering the basin.

6. The basin shall have a ponding depth of less than 10 feet, with at least 1 foot

of freeboard above the 100-year flood elevation or emergency spillway

elevation, whichever is higher.

7. The basin shape should be designed with a length to width ratio of 3:1 in

either a long narrow shape or a teardrop shape, to the maximum extent

practical.

8. The basin shall be seeded with vegetation that is tolerant of inundation.

9. The basin outlet structure shall discharge to a stable outlet.

C. Storm Sewers

1. Unless otherwise approved by the Director of Public Works, all storm sewer

in the public right-of-way (R/W) shall be constructed of reinforced concrete

pipe of appropriate class for the expected loading. Storm sewer materials

outside of the R/W shall be subject to approval of the Director of Public

Works.

2. The minimum allowable pipe diameter shall be 12 inches.

3. Sewer grades shall be designed so that, in general, a minimum of 2-foot

cover is maintained over the top of the pipe. Pipe cover less than the

minimum may be used upon site-specific approval by the Director of Public

Works. Uniform slopes shall be maintained between inlets, manholes and

inlet to manhole. Minimum and maximum allowable slopes shall be those

capable of producing velocities between 2 and 12 feet per second,

respectively, when the sewer is flowing full. Velocities lower than the

minimum or higher than the maximum may be used upon site-specific

approval by the Director of Public Works.

4. The maximum distance for overland flow of stormwater runoff to an

underground storm sewer system shall be 600 feet unless a longer distance

is approved by the Director of Public Works.

City of Whitewater

Erosion Control and Stormwater Management Requirements

Section 2 – Performance Standards

5. All inlets and catch basins shall be constructed with a 12-inch sump.

D. Ditches

1. Ditch side slopes shall be no steeper than 4:1.

2. Under drains may be required for ditch grades of 0.75 percent or less.

3. Ditches and open channels shall be protected with erosion mat as necessary

to prevent erosion. The erosion mat shall be of an approved type and

application specified in the “Erosion Control Product Acceptability List”, most

current revision, by the Wisconsin Department of Transportation.

E. Culverts

1. Culverts and similar structures shall have a capacity that meets or exceeds

the capacity of the surface drainage way and shall be a minimum of 12 inches

in diameter. The flow line of a culvert shall match the flow line of the

surface drainage way.

2. Culvert pipe materials and cover requirements shall be the same as pipe

materials for storm sewers.

3. Culverts shall not create backwater that adversely impacts upstream

properties. Design of new culverts shall consider impacts of future upstream

development.

4. End sections shall be provided for all culverts. Grates shall be required on

end sections for all culverts greater than 18 inches in diameter.

City of Whitewater

Erosion Control and Stormwater Management Requirements

Section 2 – Performance Standards

SECTION

2

PERFORMANCE

STANDARDS

2.01 EROSION AND SEDIMENT CONTROL PERFORMANCE STANDARDS

A. Total Suspended Solids Removal Goals

1. The Erosion and Sediment Control Plan shall include best management

practices (BMPs) that, by design, achieve to the maximum extent practicable,

a reduction of 80 percent of the sediment load carried in runoff based on an

average annual rainfall, as compared with no sediment or erosion controls

until the construction site has undergone final stabilization. An 80 percent

sediment reduction shall meet the requirement of this paragraph. Erosion

and sediment control BMPs may be used alone or in combination to meet the

requirements of this paragraph. Credit toward meeting the sediment

reduction may be given for limiting the duration or area, or both, of

land-disturbing construction activity.

2. If BMPs cannot be designed and implemented to reduce the sediment load

by 80 percent, based on an average annual rainfall, the plan shall include a

written and site-specific explanation as to why the 80 percent reduction goal

is not attainable, and the sediment load shall be reduced to the maximum

extent practicable.

3. DNR is required by recent rule revisions to develop technical standards to

provide guidance for measurement and evaluation of this performance

standard. Measurement and evaluation of this performance standard shall

be based on guidance published by the Department of Natural Resources.

Until such guidance is published, total suspended solids removal shall be

achieved to the maximum extent practical through implementation of

approved BMP’s.

B. Required Best Management Practices

Where appropriate, the plan shall include sediment controls to do all of the following to the

maximum extent practicable:

1. Each site shall provide an access drive and parking area of sufficient

dimensions and design, surfaced with a material that will prevent erosion and

minimize tracking or washing of soil onto public or private roadways. All non

paved access drives shall be designed so that stormwater runoff from adjacent

areas does not flow down the drive surface.

City of Whitewater

Erosion Control and Stormwater Management Requirements

Section 2 – Performance Standards

2. Any significant amount of runoff from upslope land area, rooftops, or other

surfaces that drain across the proposed land disturbance shall be diverted

around the disturbed area, if practical. Any diversion of upslope runoff shall

be done in a manner that prevents erosion of the flow path and the outlet.

3. Any cuts and fills shall be planned and constructed to minimize the length

and steepness of slope and stabilized in accordance with the approved

erosion control plan timelines and standards of this document.

4. Open channels shall be stabilized as required to prevent erosion.

5. Inlets to storm drains, culverts, and other stormwater conveyance systems

shall be protected from siltation until final site stabilization.

6. Water pumped from the site shall be treated by temporary sedimentation

basins or other appropriate controls designed for the highest dewatering

pumping rate. Water may not be discharged in a manner that causes erosion

of the site or receiving channels.

7. All waste and unused building materials shall be properly disposed of and not

allowed to be carried by runoff into a receiving channel or storm sewer

system.

8. All off-site sediment deposits occurring as a result of a storm event shall be

cleaned up by the end of the next workday. All other off-site sediment

deposits occurring as a result of land-disturbing activities shall be cleaned up

by the end of the workday. Flushing may not be used unless the sediment

will be controlled by a filter fabric barrier, sediment trap, sediment basin, or

equivalent.

9. All activities on the site shall be conducted in a logical sequence to minimize

the area of bare soil exposed at one time. Existing vegetation shall be

maintained as long as possible.

10. Soil stockpiles shall be located no closer than 25 feet from lakes, streams,

wetlands, ditches, drainage ways, or roadway drainage systems. Stockpiles

shall be stabilized by mulching, vegetative cover, tarps, or other means if

remaining 20 days or more.

11. For any disturbed area that remains inactive for greater than 7 working days,

or where grading work extends beyond annual permanent seeding deadlines,

the City of Whitewater may require the site to be treated with temporary

stabilization measures.

City of Whitewater

Erosion Control and Stormwater Management Requirements

Section 2 – Performance Standards

12. When the disturbed area has been stabilized by permanent vegetation or

other means, temporary BMPs such as silt fences, straw bales, and sediment

traps shall be removed and these areas stabilized.

2.02 STORMWATER MANAGEMENT PERFORMANCE STANDARDS

A. Total Suspended Solids

1. BMPs shall be designed, installed, and maintained to control total suspended

solids carried in runoff from the post construction site as follows:

a. For new development, by design, reduce to the maximum extent

practicable, the total suspended solids load by 80 percent, based on

the average annual rainfall, as compared to no runoff management

controls. An 80 percent total suspended solids reduction shall meet

the requirements of this subdivision.

b. For redevelopment sites one acre or larger, by design, reduce to the

maximum extent practicable, the total suspended solids load by 40

percent, based on the average annual rainfall, as compared to no

runoff management controls. A 40 percent total suspended solids

reduction shall meet the requirements of this subdivision.

c. Notwithstanding items a. and b. if the design cannot achieve the

applicable total suspended solids reduction specified, the stormwater

management plan shall include a written and site-specific explanation

why that level of reduction is not attained, and the total suspended

solids load shall be reduced to the maximum extent practicable.

d. Measurement and evaluation of this standard shall be based on

guidance published by the DNR. In the absence of such guidance,

total suspended solids removal shall be achieved to the maximum

extent practical through implementation of approved BMPs.

B. Peak Discharge

1. By design, BMPs shall be employed to maintain or reduce the peak runoff

discharge rates, to the maximum extent practicable, as compared to pre-

development conditions for the 2- through 100-year design storm applicable

to the development site.

City of Whitewater

Erosion Control and Stormwater Management Requirements

Section 2 – Performance Standards

Hydrologic Soil Group

A

B

C

D

Runoff Curve Number

56

70

79

83

Table 2.02-1 Maximum predevelopment Runoff Curve Numbers for Cropland

Areas

2. Predevelopment conditions shall assume “good hydrologic conditions” for

appropriate land covers as identified in TR-55 or an equivalent methodology.

The meaning of “hydrologic soil group” and “runoff curve number” are as

determined in TR-55. However, when predevelopment land cover is

cropland, rather than using TR-55 values for cropland, the runoff curve

numbers in Table 2.02-1 shall be used.

C. Runoff Volume

At locations where site conditions permit and where technically feasible, infiltration of

stormwater to reduce the volume of runoff may be required. If stormwater infiltration can

be demonstrated, the reduced volume may be taken into account when designing practices

to meet the peak flow control and pollution control requirements of this ordinance.

Where applicable, evaluation of the need for, appropriateness of, and required volume of

infiltration shall be based on the most current DNR rules and technical standards.

Infiltration shall not be permitted at locations specifically excluded in the DNR rules.

D. Oil and Grease

Fueling and vehicle maintenance areas shall have BMPs designed, installed, and

maintained to reduce petroleum within runoff so that the runoff that leaves the site contains

no visible petroleum sheen.

E. Protective Areas

1. A vegetated protective area with the width measured horizontally, specified in

Table 2.02-2, shall be provided from the top of the channel (per definition in

Section 5) of lakes, streams, and rivers or the delineated boundary of

wetlands.

2. Impervious surfaces shall be kept out of the protective area unless

impractical, with consideration of the planned use. The stormwater

management plan shall contain a written site-specific explanation for any

parts of the protective area that are disturbed during construction.

City of Whitewater

Erosion Control and Stormwater Management Requirements

Section 2 – Performance Standards

Type of Resource Protective Area

Outstanding and Exceptional Resource Waters 75 feet

Perennial/Intermittent Streams per USGS Map 50 feet

Lakes and Wetlands 50 feet

Other Waterways with Drainage Areas > 130 ac 10 feet

Table 2.02-2 Types of Resources and Protective areas

3. Where land-disturbing construction activity occurs within a protective area,

and where no impervious surface is present, adequate sod or self-sustaining

vegetative cover of 70 percent or greater shall be established and

maintained. The adequate sod or self-sustaining vegetative cover shall be

sufficient to provide for bank stability, maintenance of fish habitat, and

filtering of pollutants from upslope overland flow areas under sheet flow

conditions. Non vegetative materials, such as rock riprap, may be employed

on the bank as necessary to prevent erosion, such as on steep slopes or

where high velocity flows occur.

In selecting the vegetative cover for the protective area, existing natural

vegetative cover shall be left undisturbed, to the maximum extent practical.

Where existing vegetative cover must be disturbed, consider re-vegetating the

protective area with native plantings, where feasible.

4. Best management practices such as filter strips, swales, or wet detention

basins that are designed to control pollutants from nonpoint sources may be

located in the protective area.

5. The protective area requirement does not apply to:

a. Redevelopment sites.

b. In-fill development areas less than 5 acres.

c. Structures that cross or access surface waters such as boat landings,

bridges, and culverts.

d. Structures constructed in accordance with s. 59.692(1v), Wis. Stats.

e. Post construction sites from which runoff does not enter the surface

water, except to the extent that vegetative ground cover is necessary

to maintain bank stability.

City of Whitewater

Erosion Control and Stormwater Management Requirements

Section 4 – Submittal Requirements

6. Stormwater Conveyance Systems

a. Storm Sewers shall be designed to convey the peak discharge for a

10-year frequency storm event.

b. Cross culverts shall be designed to convey the peak discharge for a

25-year frequency storm event.

c. Ditches shall be designed to convey the peak discharge for a 25-year

frequency storm event.

d. All conveyance systems shall be designed to safely pass the 100-year

storm flow without damage to adjacent structures. Unless waived by the

City of Whitewater, all new structures shall be constructed at least 2 feet

higher than the estimated 100-year overflow elevation.

City of Whitewater

Erosion Control and Stormwater Management Requirements

Section 4 – Submittal Requirements

SECTION

3

GENERAL

REQUIREMENTS

3.01 GENERAL CONSIDERATIONS

A. All concentrated stormwater discharges leaving a site must be conveyed into an

existing channel, storm sewer, or overland flow path with adequate downstream

stormwater capacity and shall not result in increased flood hazard, erosion, or other

adverse impacts.

B. Natural topography and land cover features such as natural swales, natural

depressions, native soil infiltrating capacity, and natural groundwater recharge areas

shall be preserved and used, to the extent possible, to meet the requirements of this

section.

C. Emergency overland flow for all stormwater facilities shall be provided to prevent

exceeding the safe capacity of downstream drainage facilities and prevent

endangerment of downstream property or public safety.

City of Whitewater

Erosion Control and Stormwater Management Requirements

Section 4 – Submittal Requirements

SECTION

4

SUBMITTAL

REQUIREMENTS

4.01 EROSION AND SEDIMENT CONTROL PLAN

Submittal requirements for Erosion and Sediment Control Plans are summarized below.

The Director of Public Works may waive a portion of these submittal requirements where

such information is not necessary to demonstrate compliance with the ordinance.

A. Responsible Party and Legal Description

1. Name, address, and telephone number for the following or their designees:

landowner; developer; project engineer for practice design and certification;

person(s) responsible for installation of stormwater management practices;

and person(s) responsible for maintenance of stormwater management

practices prior to the transfer, if any, of maintenance responsibility to another

party.

2. A site location map and proper legal description of the property proposed to

be developed, referenced to the US Public Land Survey system or to block

and lot numbers within a recorded land subdivision plat.

B. Predevelopment Site Conditions Mapping

1. A USGS Quadrangle or other appropriate map showing the project location

and nearby regional water resources potentially impacted by the project.

2. A copy of the applicable Soils Survey Map showing predominant soil types

and hydrologic soil groups.

3. Mapping or description of existing cover type and condition.

4. A pre-developed conditions site map including the following information

described below. Mapping shall include enough of the contiguous properties

to show runoff patterns onto, through, and from the site.

a. Existing topographic contours of the site at a contour interval not to

exceed 2 feet.

b. Property lines.

c. Existing flow paths and direction across the site.

d. Outlet locations identifying where stormwater drainage leaves the

property.

City of Whitewater

Erosion Control and Stormwater Management Requirements

Section 4 – Submittal Requirements

e. Drainage basin divides and subdivides to all outlet locations where

stormwater drainage leaves the property.

f. Existing drainage structures on and adjacent to the site.

g. Watercourses that may affect or be affected by runoff from the site.

h. Lakes, streams, wetlands, channels, ditches, and other watercourses

on and immediately adjacent to the site.

i. Limits of the 100-year

floodplain.

C.

Proposed Site Grading and Erosion Control Plan

A Site Grading and Erosion Control Plan shall be provided that includes the

following items. The plan shall be at an appropriate scale for the size of the

development.

1. Boundaries of the construction site.

2. Drainage patterns and approximate slopes anticipated after major grading

activities.

3. Areas of soil disturbance.

4. Location of major structural and nonstructural controls identified in the plan.

a. Location of areas where stabilization practices will be employed.

b. Areas which will be vegetated following construction.

5. Extent of wetland acreage on the site and locations where stormwater is

discharged to a surface water or wetland.

D. Calculations

Calculations shall be provided including computer modeling input and output files,

as needed, to demonstrate compliance with ordinance performance standards. All

major assumptions used in developing input parameters shall be clearly stated. The

drainage basin areas used in making the calculations shall be clearly cross-

referenced to the required map(s).

City of Whitewater

Erosion Control and Stormwater Management Requirements

Section 4 – Submittal Requirements

E. Narrative

A narrative description of the proposed Erosion and Sediment Control Plan shall be

provided, including the following:

1. Name of the immediate named receiving water from the United States

Geological Service 7.5 minute series topographic maps, as well as locations

of all surface waters and wetlands within one mile of the construction site.

2. A description of the site and the nature of the construction activity.

3. A sequence of construction of the development site, including stripping and

clearing; rough grading; construction of utilities, infrastructure, and buildings;

and final grading and landscaping. Sequencing shall identify the expected

date on which clearing will begin, the estimated duration of exposure of

cleared areas, areas of clearing, installation of temporary erosion and

sediment control measures, and establishment of permanent vegetation.

4. Estimates of the total area of the site and the total area of the site that is

expected to be disturbed by construction activities.

5. Estimates, including calculations, if any, of the runoff coefficient of the site

before and after construction activities are completed.

6. A description of appropriate controls and measures that will be performed at

the site to prevent pollutants from reaching waters of the state. The plan

shall clearly describe the appropriate control measures for each major

activity and the timing during the construction process that the measures will

be implemented. The description of erosion controls shall include, when

appropriate, the following minimum requirements:

a. Description of interim and permanent stabilization practices, including

a practice implementation schedule. Site plans shall ensure that

existing vegetation is preserved where attainable and that disturbed

portions of the site are stabilized.

b. Description of structural practices to divert flow away from exposed

soils, store flows, or otherwise limit runoff and the discharge of

pollutants from the site. Unless otherwise specifically approved in

writing by the City of Whitewater, structural measures shall be

installed on upland soils.

City of Whitewater

Erosion Control and Stormwater Management Requirements

Section 4 – Submittal Requirements

c. Descriptions of any other practices proposed to meet requirements of

the ordinance and prevent erosion from the site.

4.02 STORMWATER MANAGEMENT PLAN SUBMITTAL REQUIREMENTS

Submittal requirements for Stormwater Management Plans are summarized below. The

Director of Public Works may waive a portion of these submittal requirements where such

information is not necessary to demonstrate compliance with the ordinance.

A. Responsible Party and Legal Description

The stormwater management plan required under S.08 (1) should contain, at a minimum,

the following information:

1. Name, address, and telephone number for the following or their designees:

landowner; developer; project engineer for practice design and certification;

person(s) responsible for installation of stormwater management practices;

and person(s) responsible for maintenance of stormwater management

practices prior to the transfer, if any, of maintenance responsibility to another

party.

2. A proper legal description of the property proposed to be developed,

referenced to the U.S. Public Land Survey system or to block and lot

numbers within a recorded land subdivision plat.

B. Predevelopment Site Conditions Mapping

1. A USGS Quadrangle or other appropriate map showing the project location

and nearby regional water resources potentially impacted by the project.

2. A copy of the applicable Soils Survey Map showing predominant soil types

and hydrologic soil groups.

3. Mapping or description of existing cover type and condition.

4. A pre-developed conditions site map including the following information

described below. Mapping shall include enough of the contiguous properties

to show runoff patterns onto, through, and from the site:

a. Existing topographic contours of the site at a contour interval not to

exceed 2 feet.

b. Property

lines.

City of Whitewater

Erosion Control and Stormwater Management Requirements

Section 4 – Submittal Requirements

c. Existing flow paths and direction across the site.

d. Outlet locations identifying where stormwater drainage leaves the

property.

e. Drainage basin divides and subdivides to all outlet locations where

stormwater drainage leaves the property.

f. Existing drainage structures on and adjacent to the site.

g. Watercourses that may affect or be affected by runoff from the site.

h. Lakes, streams, wetlands, channels, ditches, and other watercourses

on and immediately adjacent to the site.

i. Limits of the 100-year floodplain.

j. Location of wells and wellhead protection areas covering the project

area and delineated pursuant to s. NR 811.16, Wis. Adm. Code.

C. Post development Site Conditions Mapping

1. Proposed pervious areas including vegetative cover type and condition.

2. Proposed impervious surfaces including all buildings, structures, and

pavement.

3. Proposed topographic contours of the site at a scale not to exceed one foot.

4. Proposed drainage network including enough of the contiguous properties to

show runoff patterns onto, through, and from the site; locations and

dimensions of drainage easements.

5. Locations of maintenance easements specified in the maintenance

agreement.

6. Flow path and direction for all stormwater conveyance sections.

7. Location and type of all stormwater management conveyance and treatment

practices, including the on-site and off-site tributary drainage area.

8. Location and type of conveyance system that will carry runoff from the

drainage and treatment practices to the nearest adequate outlet such as a

curbed street, storm drain, or natural drainage way.

City of Whitewater

Erosion Control and Stormwater Management Requirements

Section 4 – Submittal Requirements

9. Proposed drainage divides and subdivides identified to each outlet location

where stormwater will discharge from the proposed development site.

D. Detailed Drawings

Detailed drawings including cross sections and profiles of all permanent stormwater

conveyance and treatment practices.

E. Calculations

Calculations, including computer modeling input and output files, as needed to demonstrate

compliance with ordinance performance standards. All major assumptions used in

developing input parameters shall be clearly stated. The drainage basin areas used in

making the calculations shall be clearly cross-referenced to the required map(s).

F. Narrative

A narrative including, at a minimum, the following:

1. A description of methodologies and major assumptions used in developing

hydrologic and hydraulic analyses.

2. A summary of analysis results and conclusions that shall include the

following:

a. Tables summarizing pre-developed and post developed

hydrologic parameters for each drainage basin. Tables shall include

sub basin areas, runoff curve numbers, impervious areas, and

times of concentration for pre-developed and post developed

conditions.

b. Tables summarizing peak discharge rates for the 2-year, 5-year, 10-

year, 25-year, and 100-year storm events for pre-developed, post-

developed without practices, and post developed with practices

conditions.

3. Explanation of the provisions to preserve and use natural topography and

land cover features to minimize changes in peak flow runoff rates and

volumes to surface waters and wetlands.

4. Explanation of any restrictions on stormwater management measures in the

development area imposed by wellhead protection plans and ordinances.

City of Whitewater

Erosion Control and Stormwater Management Requirements

Section 5 – Definitions

5. Results of investigations of soils and groundwater required for the placement

and design of stormwater management measures.

6. A description and installation schedule for the stormwater management

practices needed to meet the performance standards in S.07.

7. A maintenance plan developed for the life of each stormwater management

practice including the required maintenance activities and maintenance

activity schedule.

8. Cost estimates for the construction, operation, and maintenance of each

stormwater management practice.

9. Other information requested in writing by the City of Whitewater to determine

compliance of the proposed stormwater management measures with the

provisions of this ordinance.

G. Certification of Site Investigations, Plans, Designs, Computations, and Drawings

All site investigations, plans, designs, computations, and drawings shall be certified by a

Wisconsin-licensed professional engineer to be prepared in accordance with accepted

engineering practice and requirements of the ordinance.

City of Whitewater

Erosion Control and Stormwater Management Requirements

Section 5 – Definitions

SECTION

5

DEFINITIONS

5.01 DEFINITIONS

1) “Agricultural facilities and practices ” has the meaning given in s. 281.16, Wis.

Stats.

2) “Average annual rainfall” means a calendar year of precipitation, excluding snow,

which is considered typical.

3) “Best management practice” or “BMP” means structural or non-structural measures,

practices, techniques or devices employed to avoid or minimize sediment or pollutants

carried in runoff to waters of the state.

4) “Business day” means a day the office of the Director of Public Works is routinely and

customarily open for business.

5) “Cease and desist order” means a court-issued order to halt land disturbing

construction activity that is being conducted without the required permit.

6) “Combined sewer system” means a system for conveying both sanitary sewage and

stormwater runoff.

7) “Connected imperviousness" means an impervious surface that is directly connected

to a separate storm sewer or water of the state via an impervious flow path.

8) “Construction Site” means an area upon which one or more land disturbing

construction activities occur, including areas that are part of a larger common plan of

development or sale where multiple separate and distinct land disturbing

construction

activities may be taking place at different times on different schedules but under one

plan.

9) “Design storm” means a hypothetical discrete rainstorm characterized by a specific

duration, temporal distribution, rainfall intensity, return frequency, and total depth of

rainfall.

10) “Development” means residential, commercial, industrial or institutional land uses and

associated roads.

11) “Director of Public Works” means the City of Whitewater Director of Public Works or

designee.

12) “Division of land” means either a major subdivision or minor subdivision, as defined

by

Chapter 18, Land Division and Subdivision.

13) “Effective infiltration area” means the area of the infiltration system that is used to

infiltrate runoff and does not include the area used for site access, berms or

pretreatment.

14) “Erosion” means the process by which the land’s surface is worn away by the action of

wind, water, ice or gravity.

15) "Exceptional resource waters" means waters listed in s. NR 102.11, Wis. Adm.

Code.

16) “Extraterritorial Jurisdiction” means Extraterritorial Jurisdiction as defined by

Section

18.04.020 of the City of Whitewater Subdivision Ordinance.

17) "Final stabilization" means that all land disturbing construction activities at the

construction site have been completed and that a uniform, perennial, vegetative cover

has been established, with a density of at least 70% of the cover, for the unpaved areas

and areas not covered by permanent structures, or employment of equivalent permanent

stabilization measures.

18) “Financial guarantee” means a performance bond, maintenance bond, surety bond,

irrevocable letter of credit, or similar guarantees submitted to the Director of Public

Works by the responsible party to assure that requirements of the ordinance are carried

out in compliance with the stormwater management plan.

City of Whitewater

Erosion Control and Stormwater Management Requirements

Section 5 – Definitions

19) “Governing body” means town board of supervisors, county board of supervisors, city

council, village board of trustees or village council.

20) “Impervious surface” means an area that releases as runoff all or a large portion of the

precipitation that falls on it, except for frozen soil. Rooftops, sidewalks, driveways,

parking lots and streets are examples of areas that typically are impervious.

21)

“In-fill area” means an undeveloped area of land located within existing

development.

22)

“Infiltration” means the entry of precipitation or runoff into or through the soil.

23)

“Infiltration system” means a device or practice such as a basin, trench, rain

garden or swale designed specifically to encourage infiltration, but does not include

natural infiltration in pervious surfaces such as lawns, redirecting of rooftop

downspouts onto lawns or minimal infiltration from practices, such as swales or road

side channels designed for conveyance and pollutant removal only.

24)

“Karst feature” means an area or geologic feature subject to bedrock dissolution

so that it is likely to provide a conduit to groundwater, and may include caves,

enlarged fractures, mine features, exposed bedrock surfaces, sinkholes, springs,

seeps or swallets.

25)

“Land Development Activity” means any construction related activity that results

in the addition or replacement of impervious surfaces such as rooftops, roads,

parking lots, and other structures. Measurement of areas impacted by land

development activity includes areas that are part of a larger common plan of

development or sale where multiple separate and distinct land disturbing

construction activities may be taking place at different times on different schedules

but under one plan.

26)

“Land disturbing construction activity” means any man-made alteration of the

land surface resulting in a change in the topography or existing vegetative or non-

vegetative soil cover, that may result in runoff and lead to an increase in soil erosion

and movement of sediment into waters of the state. Land disturbing construction

activity includes clearing and grubbing, demolition, excavating, pit trench

dewatering, filling and grading activities.

27) “Maintenance agreement” means a legal document that provides for long-term

maintenance of stormwater management practices.

28) “MEP” or “maximum extent practicable” means a level of implementing best

management practices in order to achieve a performance standard specified in this

ordinance which takes into account the best available technology, cost effectiveness and

other competing issues such as human safety and welfare, endangered and threatened

resources, historic properties and geographic features. MEP allows flexibility in the way

to meet the performance standards and may vary based on the performance standard

and site conditions.

29) “New development” means development resulting from the conversion of previously

undeveloped land or agricultural land uses.

30) “Off-site” means located outside the property boundary described in the permit

application.

31) “On-site” means located within the property boundary described in the permit

application.

32) "Ordinary high-water mark" has the meaning given in s. NR 115.03(6), Wis. Adm.

Code.

33) “Outstanding resource waters” means waters listed in s. NR 102.10, Wis. Adm. Code.

34) “Percent fines” means the percentage of a given sample of soil, which passes through

a # 200 sieve.

City of Whitewater

Erosion Control and Stormwater Management Requirements

Section 5 – Definitions

35) “Performance standard” means a narrative or measurable number specifying the

minimum acceptable outcome for a facility or practice.

36) “Permit” means a written authorization made by the Director of Public Works to the

applicant to conduct land disturbing construction activity or to discharge post-

construction runoff to waters of the state.

37) “Permit administration fee” means a sum of money paid to the [administering

authority] by the permit applicant for the purpose of recouping the expenses incurred by

the authority in administering the permit.

38) “Pervious surface” means an area that releases as runoff a small portion of the

precipitation that falls on it. Lawns, gardens, parks, forests or other similar vegetated

areas are examples of surfaces that typically are pervious.

39)

“Pollutant” has the meaning given in s. 283.01(13), Wis. Stats.

40)

“Pollution” has the meaning given in s. 281.01(10), Wis. Stats.

41) “Post-construction site" means a construction site following the completion of land

disturbing construction activity and final site stabilization.

42) “Pre-development condition” means the extent and distribution of land cover types

present before the initiation of land disturbing construction activity, assuming that all land

uses prior to development activity are managed in an environmentally sound manner.

43) “Preventive action limit” has the meaning given in s. NR 140.05(17), Wis. Adm. Code.

44) "Redevelopment ” means areas where development is replacing older development.

45) “Responsible party” means any entity holding fee title to the property.

46) “Runoff” means stormwater or precipitation including rain, snow or ice melt or similar

water that moves on the land surface via sheet or channelized flow.

47) “Sediment” means settle able solid material that is transported by runoff, suspended

within runoff or deposited by runoff away from its original location.

48)

“Separate storm sewer” means a conveyance or system of conveyances including

roads with drainage systems, streets, catch basins, curbs, gutters, ditches,

constructed channels or storm drains, which meets all of the following criteria:

a. Is designed or used for collecting water or conveying runoff.

b. Is not part of a combined sewer system.

c. Is not draining to a stormwater treatment device or system.

d.

Discharges directly or indirectly to waters of the state.

49) “Site” means the entire area included in the legal description of the land on which the

land disturbing construction activity occurred.

50) “Stop work order” means an order issued by the Director of Public Works which

requires that all construction activity on the site be stopped.

51) “Stormwater management plan” means a comprehensive plan designed to reduce the

discharge of pollutants from stormwater after the site has under gone final stabilization

following completion of the construction activity.

52) “Stormwater management system plan” is a comprehensive plan designed to reduce

the discharge of runoff and pollutants from hydrologic units on a regional or municipal

scale.

53) "Technical standard" means a document that specifies design, predicted performance

and operation and maintenance specifications for a material, device or method.

54) “Top of the channel” means an edge, or point on the landscape, landward from the

ordinary high water mark of a surface water of the state, where the slope of the land

begins to be less than 12% continually for at least 50 feet. If the slope of the land is 12%

or less continually for the initial 50 feet, landward from the ordinary high water mark, the

top of the channel is the ordinary high water mark.

55) “TR-55” means the United States Department of Agriculture, Natural Resources

Conservation Service (previously Soil Conservation Service), Urban Hydrology for Small

Watersheds, Second Edition, Technical Release 55, June 1986.

56) “Type II distribution” means a rainfall type curve as established in the “United States

Department of Agriculture, Soil Conservation Service, Technical Paper 149, published

1973”. The Type II curve is applicable to all of Wisconsin and represents the most

intense storm pattern.

57) “Waters of the state” has the meaning given in s. 281.01 (18), Wis. Stats.

SECTION

6

FORMS

GENERAL INFORMATION

STORMWATER MANAGEMENT PERMIT APPLICATION

Send Application to:

City of Whitewater

312 West Whitewater Street

P.O. Box 178

Whitewater, Wisconsin 53190

Official Use Only

Date Received

Number

Fee Received

Reviewer

Instructions: Please type or print. Read all instructions before completing application.

Name of Project:

Applicant/Entity Receiving Permit

NameofApplicant:

First Name of Contact: LastName:_

Street(1):

Street(2):

City: State: Zip Code:

TelephoneNumber: ( )

Fax Number: ( _)

Property Owner

First Name: Last Name:

Street(1):

Street(2):

City: State: Zip Code:

TelephoneNumber: ( )

Parcel Identification Number(s):

Engineer

NameofFirm:

First Name of Contact: LastName:_

Street(1):

Street(2):

City: State: Zip Code:

TelephoneNumber: ( )

Fax Number: ( )

City of Whitewater

Stormwater Management Plan

Application Checklist

Permit

#:

Project

Name:

Date:

Please check the appropriate box: I = Included; NA = Non-Applicable

(If “NA” is checked, an explanation must be entered.)

Plan

Requirement

I

NA

Explanation/Location in Plan

A. Submittal Requirements

1. Permit Application Form

2. Maintenance Agreement

3. Financial Guarantee

4. Certification/Stamp by Wisconsin Prof. Engineer

B. Predevelopment Site Conditions Mapping

1. Location Map

2. Soils Survey Map

3. Existing Land Use Mapping

4. Pre-developed Site Conditions

a. Existing Contours

b. Property lines

c. Existing flow paths and direction

d. Outlet locations

e. Drainage basin divides and subdivides

f. Existing drainage structures on and adjacent to the site.

g. Nearby Watercourses

h. Lakes, streams, wetlands, channels, ditches, etc.

i. Limits of the 100-year floodplain;

j. Wells/Wellhead Protection Areas

C. Post-Development Site Conditions Mapping

1. Pervious Surfaces

2. Impervious Surfaces

3. One Foot Topographic Contours

4. Proposed Drainage System (including applicable off-site)

5. Proposed Easement Locations

6. Proposed Flow Paths, Overland Flow Routes

7. Proposed Outlets/Drainage Divides

D. Drawings/Details

1. Practice Location/Layout/Cross Sections

2. Outlet Structure Details

3. Ditch/Storm Sewer Plan/Profile

4. Other

E. Calculations, including computer modeling input and output files.

1. Hydrograph Parameter Calculations

2. Computer Modeling Input/Output (Pre- and Post developed)

3. Detention Pond Routing

4. Conveyance System Design

5. Other

City of Whitewater

Stormwater Management Plan

Application Checklist

Permit

#:

Project

Name:

Date:

Please check the appropriate box: I = Included; NA = Non-Applicable

(If “NA” is checked, an explanation must be entered.)

Plan

Requirement

I

NA

Explanation/Location in Plan

F. Narrative

1. Methodologies and Assumptions

2. Results/Conclusions

a. Pre-, and Post-developed parameter summary

b. Pre-, and Post-developed peak discharge Summary

3. Provisions to preserve natural topography/cover features

4. Limitations from wellhead protection plans and ordinances.

5. Results of investigations of soils and groundwater

6. Practice Installation Schedule

7. Maintenance Plan

8. Cost Estimates

9. Other Information

City of

Whitewater

Application

Checklist

Summary

Tables

Hydrologic Parameters

Basin Name

Drainage Area (Ac)

Runoff Curve Number

Time of Concentration

(min.)

Existing

Proposed

Existing

Future

Existing

Future

CITY OF WHITEWATER

Peak Discharge Summary

Outfall

No.

Storm

Frequency

Peak Discharge (cfs)

Predev.

Postdev.

w/Detention

2-Year

5-Year

10-Year

25-Year

50-Year

100-Year

Note: Provide 1 table for each oufall location.

Detention Basin Summary

Detention

Basin

Storm

Frequency

Storage

Volume

(ac-ft)

Peak Discharge (cfs)

Inflow

Discharge

Pond

Elevation

2-Year

5-Year

10-Year

25-Year

50-Year

100-Year

Note: Provide 1 table for each detention basin.

CITY OF WHITEWATER

STORMWATER MANAGEMENT PERMIT NO.

Date of

Application

Site

Address

Plat

Name_

Certified

Survey Map

Lots

No.

(s)

General Conditions:

(a) All storm water management measures shall be installed in accordance with the approved storm water

management plan and this permit.

(b) The Director of Public Works shall be notified at least 3 business days before commencing any work in

conjunction with the storm water management plan, and within 3 business days upon completion of the storm

water management practices.

(c) Practice installations shall be certified "as built" by a licensed professional engineer. Completed storm water

management practices must pass a final inspection by the Director of Public Works or its designee to

determine

if

they are in accordance with the approved storm water management plan and ordinance.

(d) The Director of Public Works shall be notified of any significant proposed modifications to an approved storm

water management plan.

(e) All storm water management practices shall be maintained in accordance with the storm water management

plan until the practices either become the responsibility of the City of Whitewater, or are transferred to

subsequent private owners as specified in the approved maintenance agreement.

(f) The City of Whitewater is authorized to perform any work or operations necessary to bring storm water

management measures into conformance with the approved storm water management plan, and consent to a

special assessment or charge against the property as authorized under such. VII of ch. 66, Wis. Stats., or to

charging such costs against the financial guarantee posted under S.10.

(g) If so directed by the Director of Public Works, all damage to adjoining facilities and drainage ways caused by

runoff, where such damage is caused by activities that are not in compliance with the approved storm water

management plan shall be repaired at the permitee’s expense.

(h) Access is permitted to the Director of Public Works or its designee for the purpose of inspecting the property for

compliance with the approved storm water management plan and this permit.

APPLICANT

Owner

MUST FILL (please print or type full name)

IN

BOXED

Address

AREA

Signature or Owner or Authorized Representative

Gross

Aggregate

Area

(Square

Feet)

SPECIAL

CONDITIONS:

CONDITIONAL

APPROVAL:

Administrative

Authority Title Date

Permit VALID for a period of twelve (12) months from date of issuance by Director of Public

Works and all work must be completed prior to the expiration unless authorized in writing from

the Director of Public Works.

GENERAL

INFORMATION

CONSTRUCTION SITE EROSION CONTROL PERMIT

APPLICATION

Send Application to:

City of Whitewater

312 West Whitewater Street

P.O. Box 178

Whitewater, Wisconsin 53190

Official Use Only

Date Received

Number

Fee Received

Reviewer

Instructions: Please type or print. Read all instructions before completing application.

Name of Project:

Applicant/Entity Receiving Permit

NameofApplicant:

First Name of Contact: LastName:_

Street(1):

Street(2):

City: State: Zip Code:

TelephoneNumber:( )

Fax Number: ( )

Property Owner

First Name: Last Name:

Street(1):

Street(2):

City: State: Zip Code:

TelephoneNumber: ( )

Parcel Identification Number(s):

Engineer (Where Applicable)

NameofFirm:

First Name of Contact: LastName:_

Street(1):

Street(2):

City: State: Zip Code:

TelephoneNumber: ( )

Fax Number: ( )

CONDITIONAL

APPROVAL:

Administrative Authority

Title

Date

Permits issued under this section shall be valid for a period of 180 days, or the length of the building permit or other

construction authorizations, whichever is longer, from the date of issuance. The Director of Public Works may extend

the period one or more times for up to an additional 180 days. The Director of Public Works may require additional

BMPs as a condition of the extension if they are necessary to meet the requirements of this ordinance.

CITY OF

WHITEWATER

CONSTRUCTION SITE EROSION CONTROL PERMIT NO.

Date of

Application

Site

Address

Plat

Name_

Certified

Survey Map

Lots

No.

(s)

Permit Conditions:

(a) Permittee shall notify the Director of Public Works 48 hours prior to commencing any land disturbing

construction activity.

(b) Permittee shall notify the Director of Public Works of practice installation within 5 days of installation.

(c) Permittee shall obtain permission in writing from the Director of Public Works prior to any modification pursuant

to S.08(2) of the erosion and sediment control ordinance.

(d) Permittee shall install all practices as identified in the approved erosion and sediment control plan.

(e) Permittee shall maintain all road drainage systems, stormwater drainage systems, BMPs and other facilities

identified in the erosion and sediment control plan.

(f) Permittee shall repair any siltation or erosion damage to adjoining surfaces and drainage ways resulting from

land disturbing construction activities and document repairs in a site erosion control log. Remove accumulated

sediment from downstream culverts, storm sewers, and other drainage facilities.

(g) Permittee shall inspect the practices within 24 hours after each rain of 0.5 inches or more which results in

runoff during active construction periods, and at least once each week, make needed repairs and document the

findings of the inspections in a site erosion control log with the date of inspection, the name of the person

conducting the inspection, and a description of the present phase of the construction at the site.

(h) Permittee shall allow the Director of Public Works to enter the site for the purpose of inspecting compliance with

the erosion and sediment control plan or for performing any work necessary to bring the site into compliance

with the control plan. Permittee shall keep a copy of the erosion and sediment control plan at the construction

site.

APPLICANT

Owner

MUST FILL (please print or type full name)

IN

BOXED

Address

AREA

Signature or Owner or Authorized Representative

Area

of

Land

Disturbance

(Square

Feet)

SPECIAL

CONDITIONS:

City of Whitewater Construction Site

Erosion Control Plan Application

Checklist

(Sites > One

Acre)

Project

Name:

Permit #:

Date:

Please check the appropriate box: I = Included; NA = Non-Applicable (If “NA” is checked, an explanation must be entered.)

Plan

Requirement

I

NA

Explanation/Location in Plan

A. Submittal Requirements

1. Permit Application Form

B. Predevelopment Site Conditions Mapping

1. Location Map

2. Soils Survey Map

3. Existing Land Use Mapping

4. Pre-developed Site Conditions

a. Existing Contours

b. Property lines

c. Existing flow paths and direction

d. Outlet locations

e. Drainage basin divides and subdivides

f. Existing drainage structures on and adjacent to the site.

g. Nearby Watercourses

h. Lakes, streams, wetlands, channels, ditches, etc.

i. Limits of the 100-year floodplain;

C. Proposed Site Grading and Erosion Control Plan

1. Boundaries of the construction site.

2. Drainage Patterns/slopes after grading activities

3. Areas of land disturbance

4. Locations of structural and nonstructural controls

5. Drainage basin delineations and outfall locations

D. Drawings/Details

1. Practice Location/Layout/Cross Sections

2. Construction Details

E. Calculations, as required to demonstrate ordinance compliance

F. Narrative

1. Name of receiving waters

2. Site Description/Nature of construction activity

3. Sequence of Construction

4. Estimate of site area and disturbance area

5. Pre- and post developed runoff coefficients

6. Description of proposed controls, including

a. Interim and permanent stabilization practices

b. Practices to divert flow from exposed soils

c. Practices to store flows or trap sediment

d. Any other practices proposed to meet ordinance