Less than one acre disturbance (regardless of the lot or property size).
A. Mandated practices:
1. A method to prevent or reduce soil from leaving a site via entries or roads. This may include a tracking pad or tire washing stand designed and installed to meet DNR Standard 1057. Other means of compliance include a gravel mulch, frozen soil, bedrock or some other physical means to prevent soil from leaving the site on vehicle tires which is equivalent to the tracking pad or tire washing stand.
2. Storm water inlet protection. Inlet protection may be accomplished by using DNR Technical Standard, number 1050, “Storm Drain Inlet Protection for Construction Sites". The protection of stormwater inlets in the code is specific to “on-site" inlets; however an off-site inlet may create a direct conduit to a water of the state, which links any inlet that leads to a water of the state to the #3 mandated practice. In that case, special care should be taken to protect both types of inlets from sediment in runoff from a construction site.
3. Protection of adjoining waters of the state. The installation of practices is necessary if runoff from the disturbance could impact a water of the state. Practices may include channel erosion mats, silt fences, vegetative buffers or any other practices applicable to the specific site.
4. Drainage way protection. Any ditches or drainage ways that flow off-site must be protected with appropriate best management practices (BMPs). This may include but is not limited to ditch checks, channel erosion control mats or riprap.
5. Dewatering activity sediment reduction. Any dewatering necessary on the construction site must include measures to reduce the sediment in the water leaving the site. Dewatering BMPs may include filters, fiber rolls or gravel bag berms.
6. Stockpile protection. Any soil stockpiles which are left more than 7 days must be protected by seeding and mulching, erosion mat, silt fencing, covering or other methods. This does not include fill or topsoil piles that are in active use.
B. In addition to mandated practices, the owner/contractor or designer must choose one or more of the following methods in order to achieve compliance with the standards.
1. The Revised Universal Soil Loss Equation may be used to determine the amount of soil lost from a site in order to stay below the 5 tons/acre/year for sand, loamy sand, sandy loam, loam, sandy clay loam, clay loam, sandy clay, silty clay or clay textures or the 7.5 tons/acre/year soil loss for silt, silty clay loam or silt loam textures. The Department-accepted version of an Excel worksheet that is used to calculate the soil loss is available at:
http://dsps.wi.gov/Default.aspx?Page=224e686e-b2b6-44ac-b79d-d8ad3d3cb560.
2. Silt fence may be placed in accordance with the DNR Technical Standard 1056 and remain on the site until the pervious area is stabilized. This practice, in addition to the mandated practices in part “A" is accepted by the Department of Safety and Professional Services as compliant with the 40% reduction in sediment load goal.
3. The site may be seeded and mulched, erosion control mat may be installed or polymers may be applied. The erosion control BMPs must be applied within one week of disturbance. Seeding must be accomplished in accordance with DNR Technical Standard 1059 and mulching with DNR Technical Standard 1058. Erosion control mat must be installed in accordance with DNR Technical Standards 1052 and 1053. Polymer application must be done in accordance with DNR Technical Standard 1051. This method is only acceptable when the maximum slope length is 300 feet and the maximum slope is no more than that specified in Table A-321.125-1 and Table A-321.125-2.
4. Practices may be included in the erosion and sediment control plan for the site that achieve compliance with the 40% reduction in sediment load in the runoff from the site. Table A-321.125-3 lists several erosion and sediment control BMPs and the USEPA (United States Environmental Protection Agency) efficiency rating for that BMP.
5. A unique design may be submitted with the UDC permit application for review.
Table A-321.125-1
Slope Limitations for Permissible Soil Loss with max. 300‵ slope length1
When sites are seeded, mulched or otherwise stabilized within one week of disturbance2
- See PDF for table 
1 The information in the table is derived from Grant County rainfall information and the use of the Revised Universal Soil Loss Equation. The slope limitation refers to the maximum slope permitted in order to achieve code compliance for the site specifics in the table. Opening date is the 15th of each month and closing is the 22nd. End date is 60 days past closing date.
2 Stabilization may be accomplished by temporary seeding and mulching, permanent seeding and mulching, application of polymers or placement of erosion control mats. Additionally, the mandated practices specific to the site must be in place.
Table A-321.125-2
Slope Limitations for Permissible Soil Loss with max. 300‵ slope length1
When sites are seeded, mulched or otherwise stabilized within 4 weeks of disturbance2
- See PDF for table
1 The information in the table is derived from Grant County rainfall information and the use of the Revised Universal Soil Loss Equation. The slope limitation refers to the maximum slope permitted in order to achieve code compliance for the site specifics in the table. Opening date is the 15th of each month and closing is the 15th of the following month End date is 60 days past closing date.
2 Stabilization may be accomplished by temporary seeding and mulching, permanent seeding and mulching, application of polymers or placement of erosion control mats. Additionally, the mandated practices specific to the site must be in place.
Erosion and sediment control for construction sites having a land-disturbance area of one acre or more is regulated by the Department of Natural Resources
Table A-321.125-3
1 BMP efficiency is derived from information provided on the Environmental Protection Construction Erosion Control website in August, 2006 and only when the BMP is installed per the listed standard.
2 Standard number refers to the Wisconsin Department of Natural Resources Conservation Practice Standard number.
3 This efficiency measure is provided by the Department of Safety and Professional Services, Industry Services Division.
4 This efficiency measure is provided by the Department of Safety and Professional Services, Industry Services Division, and only for a short duration as described in the standard.
There are several BMPs that do not have an efficiency assigned by the EPA. These include mandatory controls such as inlet protection, drainage way protection (riprap) and tracking pads. Diversions, both temporary and permanent are also not included in Table A-321.125-2. Diversions impact the erosion on a site by shortening the length of slope in the Revised Universal Soil Loss Equation (RUSLE).
Following is an example of an erosion and sediment control plan (Figure A-321.125). This plan may be used for reference, however each site is unique and each plan will address the site-specific issues.
Figure A-325.125-1
Figure A-325.125-2
Following are reprints of the DNR Erosion Control Technical Standards, also available at
Channel Erosion Mat
1053 (8/05)
Wisconsin Department of Natural Resources
Conservation Practice Standard
Note: Words in the standard that are shown in italics are described in XI. Definitions. The words are italicized the first time they are used.
I. Definition
A protective soil cover of straw, wood, coconut fiber or other suitable plant residue, or plastic fibers formed into a mat, usually with a plastic or biodegradable mesh on one or both sides. Erosion mats are rolled products available in many varieties and combination of materials and with varying life spans.
II. Purpose
The purpose of this practice is to protect the channel from erosion or act as turf reinforcement during and after the establishment of grass or other vegetation in a channel. This practice applies to both Erosion Control Revegative Mats (ECRM1) and Turf-Reinforcement Mats (TRM).
III. Conditions Where Practice Applies
This standard applies where runoff channelizes in intermittent flow and vegetation is to be established. Some products may have limited applicability in projects adjacent to navigable waters.
IV. Federal, State, and Local Laws
Users of this standard shall be aware of applicable federal, state, and local laws, rules, regulations, or permit requirements governing the use and placement of erosion mat. This standard does not contain the text of federal, state, or local laws.
V. Criteria
This section establishes the minimum standards for design, installation and performance requirements. To complete the shear calculations, a 2 year, 24 hour storm event shall be used to calculate depth of flows for an ECRM. For sizing a TRM, use the depth of flow corresponding to the maximum design capacity of the channel.
Only mats listed in the Wisconsin Department of Transportation (WisDOT) Erosion Control Product Acceptability List (PAL) will be accepted for use in this standard.
To differentiate applications WisDOT organizes erosion mats into three classes of mats, which are further broken down into various Types.
A. Class I: A short-term duration (minimum of 6 months), light duty, organic ECRM with plastic or biodegradable
netting.
1. Type A – Only suitable for slope applications, not channel applications.
2. Type B – Double netted product for use in channels where the calculated (design) shear stress is 1.5 lbs/ft2 or less.
B. Class II: A long-term duration (three years or greater), organic ECRM.
1. Type A – Jute fiber only for use in channels to reinforce sod.
2. Type B – For use in channels where the calculated (design) shear stress is 2.0 lbs/ft2 or less. Made with plastic or biodegradable mat.
3. Type C – A woven mat of 100% organic material for use in channels where the calculated (design) shear stress is 2.0 lbs/ft2 or less. Applicable for use in environmentally sensitive areas where plastic netting is inappropriate.
C. Class III: A permanent 100% synthetic ECRM or TRM. Class I, Type B erosion mat or Class II, Type B or C erosion mat must be placed over a soil filled TRM.
1. Type A – An ECRM for use in channels where the calculated (design) shear stress of 2.0 lbs/ft2 or less.
2. Type B – A TRM for use in channels where the calculated (design) shear stress of 2.0 lbs/ft2 or less.
3. Type C – A TRM for use in channels where the calculated (design) shear stress of 3.5 lbs/ft2 or less.
4. Type D – A TRM for use in channels where the calculated (design) shear stress of 5.0 lbs/ft2 or less.
VI. Installation
A. ECRM shall be installed after all topsoiling, fertilizing, liming, and seeding is complete.
B. Erosion mats shall extend for whichever is greater: upslope one-foot minimum vertically from the ditch bottom or 6 inches higher than the design flow depth.
C. The mat shall be in firm and continuous contact with the soil. It shall be anchored, overlapped, staked and entrenched per the manufacturer's recommendations.
D. TRM shall be installed in conjunction with the topsoiling operation and shall be followed by ECRM installation.
E. At time of installation, document the manufacturer and mat type by saving material labels and manufacturer's installation instructions. Retain this documentation until the site is stabilized.
VII. Considerations
A. Erosion mats shall be selected so that they last long enough for the grass or other vegetation to become densely established.
B. Consider using Class II, Type C mats adjacent to waterways where trapping small animals is to be avoided.
C. Class III TRM may be appropriate as a replacement for riprap as a channel liner. Check the shear stress criteria for the channel to determine mat applicability.
D. Once a gully has formed in a channel, it is difficult to stabilize due to loss of soil structure. Even when the gully is filled with topsoil and reseeded, the soil has a tendency to dislodge in the same pattern. If gully formation continues to be a problem the design should be reevaluated, including other mat classes or riprap.
E. It may be difficult to establish permanent vegetation and adequate erosion protection in a channel with continuous flow. Consider riprap or planting wetland species with an ECRM.
F. Documentation of materials used, monitoring logs, project diary, and weekly inspection forms including erosion and stormwater management plans, should be provided to the authority charged with long term maintenance of the site.
G. Channel cross sections may be parabolic, v-shaped or trapezoidal. The use of “V" channels is generally discouraged due to erosion problems experienced.
H. To help determine the appropriate channel liner, designers can refer to the design matrix in the back of the WisDOT PAL. However, for channels not conforming to the typical section shown in the channel matrix or having a depth of flow greater than 6 inches (150 mm), the designer will need to design for an appropriate channel liner. One way to do this is to use the “tractive force" method presented in FHWA's Hydraulic Engineering Circular (HEC) No. 15. This method requires that the calculated maximum shear stress of a channel is not to exceed the permissible shear stress of the channel liner. To use this method, permissible shear stress values are stated next to each device listed in the channel matrix.
VIII. Plans and Specifications
A. Plans and specifications for installing erosion mat shall be in keeping with this standard and shall describe the requirements for applying the practice to achieve its intended purpose. The plans and specifications shall address the following:
