Construction site erosion control
When people modify the landscape, oftentimes the soil underlying the construction site is bared. This allows the land to become more susceptible to erosion, allowing sediments to flow into our waterways and negatively affect water quality.
In order to mitigate these effects, there are Best Management Practices (BMPs) defined by Wisconsin’s Department of Natural Resources. Construction BMPs can be split into two different groups: Erosion Control BMPs and Sediment Control BMPs.
Erosion Control BMPs “Directly protect the disturbed soil surface from erosion . They are the best measure for preventing erosion .” - Wisconsin Costruction Site Erosion Control Field Guide. Read on to learn a bit more about Erosion Control BMPs.
BMP 1: Channel Erosion Mat
Channel Erosion Mats are protective covers made of straw or some other plant or plastic fibers, often containing a plastic or biodegradable mesh as well. They are placed over channels that have been or are being vegetated in order to protect from erosion and reinforce the turf.
“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.”
BMP 2: Construction Site Diversion
Construction Site Diversions utilize temporary berms or channels to either collect or divert runoff. This channels clean water away from the site, where it would cause erosion, and redirects turbid waters to an area where they can settle and drop sediments
“I. Definition A temporary berm or channel constructed across a slope to collect and divert runoff.
II. Purpose To intercept, divert, and safely convey runoff at construction sites in order to divert clean water away from disturbed areas, or redirect sediment laden waters to an appropriate sediment control facility.”
BMP 3: Ditch Check
Ditch Checks are are temporary dams made from stone, straw barrels, or other approved materials that can be placed in the path of flowing water to reduce flow velocity. This allows turbid waters to drop their sediments as well as reduces active erosion.
“DEFINITION A ditch check is a temporary dam constructed across a swale, drainage ditch, channel, or other area of concentrated flow to reduce the velocity of water. Ditch checks are constructed using stone, straw bales or manufactured products identified on the Wisconsin Department of Transportation (WisDOT) Erosion Control Product Acceptability List (PAL).
PURPOSE The purpose of this practice is to reduce flow velocity and to pond water, thereby reducing active channel erosion and promoting settling of suspended solids behind the ditch check.”
BMP 4: Dust Check
Dust Checks include a variety of strategies for minimizing the amount of dust that enters the air so that there is less wind erosion, less dust is deposited into waterways, less dust is breathed in by those inhabiting the areas around the construction site, and increased visibility at the site.
“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 additives (polymers), spray-on tackifiers, chlorides, and barriers.
PURPOSE This practice may be used to: (1) Reduce wind erosion and dust. (2) Minimize deposition of dust and wind transported soils into water bodies through runoff or wind action. (3) Reduce respiratory problems. (4) Minimize low visibility conditions caused by airborne dust.”
BMP 5: Land Application of Additives for Erosion Control
Additives that are applied on land to reduce erosion include polyacrylamide and other polymers that may or may not be water soluble. These polymers help soil particles to bond together so that they are less easily eroded.
“I. Definition The land application of products containing watersoluble and non-soluble additives1 (products that are added to soil to create soil particle bonding) to temporarily reduce erosion. Products include polyacrylamide (PAM) and other polymers.
ll. Purpose The purpose of this practice is to reduce erosion deposition from wind and water on construction sites and agricultural lands until vegetation is established.”
BMP 6: Mulching for Construction Sites
Mulch is organic material that blocks raindrop impact and slows overland flow velocity to reduce erosion of bare soil. Mulch can also increase soil moisture retention and allow plant cover to establish.
“I. Definition Mulching is the application of organic material to the soil surface to protect it from raindrop impact and overland flow. Mulch covers the soil and absorbs the erosive impact of rainfall and reduces the flow velocity of runoff.
II. Purpose This practice may be used to: • Reduce soil erosion • Aid in seed germination and establishment of plant cover • Conserve soil moisture.”
BMP 7: Non-Channel Erosion Mat
Channel Erosion Mats are protective covers made of straw or some other plant or plastic fibers, often containing a plastic or biodegradable mesh as well. They are placed over newly planted grass or other vegetation in order to protect from erosion and reinforce the turf.
“I. Definition A protective soil cover made 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 combinations of material and with varying life spans.
II. Purpose The purpose of this practice is to protect the soil surface from the erosive effect of rainfall and prevent sheet erosion 1 during the establishment of grass or other vegetation, and to reduce soil moisture loss due to evaporation. This practice applies to both Erosion Control Revegetative Mats (ECRM) and Turf-Reinforcement Mats (TRM).”
BMP 8: Seeding
Seeding is the establishment of temporary or permanent vegetation in order to reduce erosion and run off on a site.
“I. Definition Planting seed to establish temporary or permanent vegetation for erosion control.
II. Purpose The purpose of temporary seeding is to reduce runoff and erosion until permanent vegetation or other erosion control practices can be established. The purpose of permanent seeding is to permanently stabilize areas of exposed soil.”
BMP 9: Trackout Control Practices
Trackout control practices are measures taken to reduce the amount of sediment “tracked out” by construction vehicles.
“DEFINITION A practice or combination of practices used to prevent, reduce, or mitigate trackout of sediment.
PURPOSE Land-disturbing construction activity generally creates conditions where a vehicle comes in contact with exposed soil, which is then transported off site and/or deposited onto streets and roadways. This sediment can then become a road hazard and be carried from streets into drainage infrastructure and discharged into waters of the state. The purpose of this standard is to identify common methods which may be used to prevent, reduce, and/or mitigate the tracking of sediment.”
BMP 10: Grading Practices for Erosion Control - Temporary
Temporary grading practices reduce erosion by roughening ???
“I. Definition Temporary 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.”
BMP 9: Vegetative Buffer for Construction Sites
Vegetative buffers, or filter or buffer strips, slow runoff velocity and halt eroded materials from washing away with densely planted vegetation.
“I. Definition An area of dense vegetation1 intended to slow runoff and trap sediment. Vegetative Buffers are commonly referred to as filter or buffer strips.
II. Purpose The purpose of this practice is to remove sediment in sheet flow by velocity reduction.”