C. When diverting clean water the diversion channel and its outfall shall be immediately stabilized for the 2-year frequency, 24-hour duration storm. Build and stabilize clean water diversions before initiating down slope land-disturbing activities.
D. Diversions shall be protected from damage by construction activities. At all points where diversion berms or channels will be crossed by construction equipment, the diversion shall be stabilized or shaped appropriately. Temporary culverts of adequate capacity may be used.
E. For diversions that are to serve longer than 30 days, the side slopes including the ridge, and down slope side the diversion shall be stabilized as soon as they are constructed. The diversion channel should be stabilized (i.e. erosion mat) or a larger sediment control practice shall be needed. For diversions serving less than 30 days, the down slope side of the diversion shall be stabilized as soon as constructed.
VI. Considerations
A. The channel cross section may be parabolic, v-shaped or trapezoidal. The use of “V" channels is generally discouraged due to potential erosion problems.
B. Ditch checks may be used to enhance sediment removal. Ditch checks shall be designed in accordance with WDNR Conservation Practice Standard Ditch Check (1062).
C. For diversion berms consider designing an emergency overflow section or bypass area to limit damage from storms that exceed the 2-year frequency 24-hour duration storm. The overflow section may be designed as a stabilized weir with riprap protection.
VII. Plans and Specifications
A. Plans and specifications for installing diversions 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:
1. Diversion location.
2. Channel grade or elevations.
3. Typical cross section.
4. Channel stabilization if required.
B. All plans, standard detail drawings, or specifications shall include schedule for installation, inspection, and maintenance. The responsible party shall be identified.
VIII. Operation and Maintenance
A. Diversions shall, at a minimum, be inspected weekly and within 24 hours after every precipitation event that produces 0.5 inches of rain or more during a 24-hour period.
B. Maintenance shall be completed as soon as possible with consideration to site conditions.
C. Accumulated sediment shall be removed when it reaches one half the height of the diversion berm. Properly dispose of any sediment removed from the diversion.
D. Diversions shall be removed and the area stabilized according to construction plans.
IX. Definitions
Temporary (I): an erosion control measure that is utilized during construction and grading operations prior to final stabilization.
Stabilized (V.C): means protecting exposed soil from erosion.
Dust Control On Construction Sites
1068 (03/04)
Wisconsin Department of Natural Resources
Conservation Practice Standard
I. Definition
Dust control includes practices used to reduce or prevent the surface and air transport of dust during construction.
Dust control measures for construction activities include minimization of soil disturbance, applying mulch and establishing vegetation, water spraying, surface roughening, applying polymers, spray-on tackifiers, chlorides, and barriers.
II. Purpose
This practice may be used to:
• Reduce wind erosion and dust.
• Minimize deposition of dust and wind transported soils into water bodies through runoff or wind action.
• Reduce respiratory problems.
• Minimize low visibility conditions caused by airborne dust.
III. Conditions Where Practice Applies
Dust control measures may be applied at any construction site, but is particularly important for sites with dry exposed soils which may be exposed to wind or vehicular traffic.
IV. Federal, State, and Local Laws
Users of this standard shall comply with applicable federal, state and local laws, rules, regulations or permit requirements governing this practice. 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.
A. The implementation of dust control shall limit the area exposed for dust generation.
B. Asphalt and petroleum based products cannot be used for dust control.
C. Mulch and Vegetation - Mulch or seed and mulch may be applied to protect exposed soil from both wind and water erosion.
Refer to WDNR Conservation Practice Standards Mulching for Construction Sites (1058) and Seeding for Construction Site Erosion Control (1059) for criteria.
D. Water - Water until the surface is wet and repeat as needed. Water shall be applied at rates so that runoff does not occur.
Treated soil surfaces that receive vehicle traffic require a stone tracking pad or tire washing at all point of access. Refer to WDNR Conservation Practice Standard Stone Tracking Pad and Tire Washing (1057) for criteria.
E. Tillage - A control measure performed with chisel type plows on exposed soils. Tillage shall begin on the windward side of the site. Tillage is only applicable to flat areas.
F. Polymers - Polymers can be an effective practice for areas that do not receive vehicle traffic. Dry applied polymers must be initially watered for activation to be effective for dust control. Refer to WDNR Conservation Practice Standard Erosion Control Land Application of Polymers (1050) for application criteria.
G. Tackifiers and Soil Stabilizers Type A - Products must be selected from and installed at rates conforming to the WisDOT Erosion Control PAL. See Section IX for reference. Example products include Latex-based and WDNR, WI
Temporary Grading Practices For Erosion Control
(Surface Roughening and Temporary Ditch Sumps)
1067 (03/04)
Wisconsin Department of Natural Resources
Conservation Practice Standard
Note: Words in the standard that are shown in italics are described in X. Definitions. The words are italicized the first time they are used.
I. Definition
Temporary1 grading practices used to minimize construction site erosion. These practices include, but are not limited to surface roughening (directional tracking and tillage) and temporary ditch sumps.
II. Purpose
The purpose of these practices are to minimize erosion and sediment transport during grading operations on construction sites.
III. Conditions Where Practice Applies
These practices apply where land disturbing activities occur on construction sites. These practices shall be used in conjunction with other erosion control practices.
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 these practices. This standard does not contain the text of federal, state, or local laws.
V. Criteria
These interim practices may be employed in addition to the approved grading plan to reduce erosion and sediment transport.
A. Surface Roughening - Surface roughening is abrading the soil surface with horizontal ridges and depressions across the slope to reduce runoff velocities.
1. Directional Tracking - The process of creating ridges with tracked vehicles on unvegetated slopes. This method is used for short durations on sites actively being grad and shall be used in conjunction with other practices. This practice shall be in place at the end of each workday.
Directional tracking involves driving a tracked vehicle up and down a slope. The tracks create horizontal grooves and ridges. The rough surface slows sheet runoff and helps to prevent rills from forming. (Conversely, if the tracked vehicle is driven along the contour the tracks create vertical grooves and ridges for the water to follow, increasing erosion.)
2. Tillage - Utilizing conventional tillage equipment to create a series of ridges and furrows on the contour no more than 15 inches apart.
B. Temporary Ditch Sump - Temporary ditch sumps are ½
to 5 cubic yard excavations made in a drainageway during earthmoving operations. Their purpose is to slow and pond runoff during the time that drainageways are being graded. Sumps shall be in place prior to anticipated rain events.
Construction involves excavating sumps (holes) in the rough ditch grade, and using the excavated material to form a dike on the downstream side of the sump.
Temporary ditch sumps are not effective perimeter controls. Other sediment control practices shall be utilized prior to channels discharging into public waterways.
VI. Considerations
A. Directional tracking may compact the soil, therefore additional seedbed preparation may be required. Refer to WDNR Conservation Practice Standard Seeding for Construction Site Erosion Control (1059) for seedbed preparation and seeding criteria.
B. When constructing a temporary ditch sump, compacting the dike provides additional stability.
C. Consider at a minimum excavating ½ cubic yard per 1% gradient, for every 500 feet of channel when constructing temporary ditch sumps.
VII. Plans and Specifications
Due to the interim nature of these practices, and the fact that location determinations are made in the field, they need only be referenced in the erosion control plan narration or general notes.
VIII. Operation and Maintenance
These practices shall be inspected and repaired or reinstalled after every runoff event.
IX. References
Virginia Department of Conservation and Recreation. 1992. Virginia Erosion and Sediment Control Handbook, Third Edition. Chapter
3 – 3.29 Surface Roughening.
Dane County. 2002. Dane County Erosion Control and Stormwater Manual, First Edition. Appendix Surface Roughening S-16.1.
X. Definitions
Temporary (I): An erosion control measure that is utilized during construction site grading activities.
Interim Sediment Control
Water Application of Polymers
1051 (11/02)