List of BMPs

List of BMPs

Ditch System	Description Paragraph
Stormwater Runoff Control (NRCS CP 570)	A suite of stormwater BMPs installed to control the quality of water leaving a construction site. The intent is to minimize erosion and sedimentation during and following construction activities.
Open Channel (NRCS CP 582) - Natural Channel/Two-stage Channel Design	A two-stage ditch is an alternative to the traditional trapezoidal drainage ditch design. The two-stage ditch contains an inset channel at the bottom that passes the channel forming flow and floodplain benches on either side that convey less frequent, high-discharge events. The objective of the two stage ditch is to mimic the function of natural systems. A two stage ditch mimics sediment transport characteristics of natural streams, removes nitrogen, and provides improved habitat. (ABH 2012, pg. 116)
Grade Stabilization Structure - Side Inlet (Various Types) (NRCS CP 410)	Side inlet controls are used to convey water from a field into a drainage ditch and are one specific type of grade stabilization structure. In many open ditched systems, spoil banks are created from side-cast material during ditch construction. In many cases, where natural ground topography slopes toward the ditch, the spoil bank forms a berm, which will impound water on a temporary basis until it can be metered through a side inlet control (typically these have been culverts). Like other grade control structures, side inlets are used to prevent the formation of gullies or stop the advancement of gullies. Grade control structures improve water quality by reducing erosion and sediment bound pollutants.
Energy Dissipation at Piped Outlets	This includes features installed to control erosion potential at the outlet of pipe. Most commonly this involves the installation of rock riprap at the outlet of the pipe. The type of energy dissipation required depends on the velocity of water leaving the piped conduit.
Sediment Basin (NRCS CP 350)	A sediment basin is a basin constructed with an engineered outlet, formed by excavation or use of an embankment, or a combination of the two. A sediment basin may also be utilized for the purpose of nutrient removal. A sediment basin functions by detaining sediment or nutrient-laden water for sufficient time to attain a desired level of treatment. Sediment basins may be used in agricultural or urban settings and are used to treat water from disturbed areas or construction sites, either on a temporary or a permanent basis. (ABH 2012, pg. 134)
Constructed (Treatment) Wetland/Constructed Wetland for Storage and Treatment (In-line or Off-channel) (NRCS CP 656)	Constructed wetlands, sometimes called treatment wetlands, are man-made systems engineered to approximate the water cleansing process of natural wetlands. In agriculture, constructed wetlands are used to filter runoff from cropland, feedlots, aquaculture operations and agricultural processing facilities. Constructed wetlands can also provide habitat for some waterfowl, other birds, amphibians and invertebrates. Constructed wetlands are effective at reducing peak flows, settling sediment, and removing nutrients.
Grade Stabilization Structure (NRCS CP 410) Rock Riffle/Rock Grade Control Structure	A rock riffle/rock grade control structure is used to control the grade and head cutting in natural or artificial channels. Grade control structures are used to prevent the formation of gullies or stop the advancement of gullies. Grade control structures can improve water quality by reducing erosion and sediment bound pollutants. The purpose of the structure is to stabilize the grade and control erosion in natural or artificial channels with a rock reinforcement of a drop in channel grade.
Grade Stabilization Structure (NRCS CP 410) Reinforced Concrete Weir Spillway	A reinforced concrete weir spillway grade control structure is used to control the grade and head cutting in natural or artificial channels. Grade control structures are used to prevent the formation of gullies or stop the advancement of gullies. Grade control structures can improve water quality by reducing erosion and sediment bound pollutants. The purpose of the structure is to stabilize the grade and control erosion in natural or artificial channels with a combination of earth embankments and concrete weir spillways.
Grade Stabilization Structure (NRCS CP 410) Reticulated Concrete Block Drop Structure	A reticulated concrete block grade control structure is used to control the grade and head cutting in natural or artificial channels. Grade control structures are used to prevent the formation of gullies or stop the advancement of gullies. Grade control structures can improve water quality by reducing erosion and sediment bound pollutants. The purpose of the structure is to stabilize the grade and control erosion in natural or artificial channels with a reticulated concrete block reinforcement of a drop in channel grade.
Lined Waterway or Outlet (NRCS CP 468)	A waterway or outlet having an erosion-resistant lining of concrete, stone, synthetic turf reinforcement fabrics, or other permanent material. This practice may be applied to support one or more of the following purposes: provide for safe conveyance of runoff from piped outlets or other water concentrations without causing erosion or flooding; stabilize existing and prevent future gully erosion,; and protect and improve water quality.
Rock Riprap	Installing rock along a bend in the channel for protection of bank or sideslope of the channel.
Streambank and Shoreline Protection (NRCS CP 580)	Streambank protection refers to both biological and structural methods of stabilizing streambanks and/or shorelines on rivers, streams, ditches, and other bodies of water. The goals of streambank and shoreline protection include preventing erosion at key areas, maintaining adequate flow conveyance, or improvements for habitat, recreation or aesthetics. The primary benefit of streambank stabilization is reduced erosion. A water quality benefit resulting from this practices is reduced sediment concentration (i.e., turbidity). (ABH 2012, pg. 109)
Stream Barbs/J-hook Vanes	Stream barbs and J-hook vanes are low dikes or sill-like structures that extend from the bank of the channel towards the stream in an upstream direction. The structures most often built of rock are oriented to deflect current away from the channel bank to improve bank stability and reduce erosion.
Stream Restoration - Toe Wood-Sod Mat	A method of channel bank stabilization and erosion control that utilizes woody debris such as tree branches, logs, or limbs. The wood debris is placed in areas that experience erosion (typically outside bends) and are covered with topsoil, sod, and shrubs.
Surge Pond	Surge Pond, also referred to as sediment or storage ponds, are used as a primary method of runoff retention, rate control, and increased water quality through the temporary storage of runoff. Sediment and nutrient laden particles drop out of suspension and allow for nutrient uptake and removal in vegetative areas. An excavated or diked area designed to store large volumes of water during a rain event and slowly release that water through an engineered outlet such as a culvert, tile, or rate control weir.
Culvert Sizing	Culvert sizing is the design of conduits through road embankments to help manage runoff timing and peak flows within a drainage system. The purpose of culvert sizing is to reduce or prevent flood damages by better utilizing distributed temporary storage and the metering of runoff, without causing a significant increase in the risk of flood damage where runoff is temporarily stored. Culvert sizing not only reduces downstream flood peaks, it also provides a more uniform level of flood protection within a drainage system. Reduced field and channel erosion, along with short-term ponding of runoff may also provide a water quality benefit. (ABH 2012, pg. 80)
Vegetated Bufferstrips -- Filter strips (NRCS CP 393)	Filter strips are an area of vegetation planted between fields and surface waters to reduce sediment, organics, nutrients, pesticides, and other contaminants in runoff. Filter strips are one of the most common BMPs used on farms state-wide. Filter strips at least 1-rod (16.5-feet) wide are required for public drainage systems in Minnesota. Filter strips reduce runoff, sediments, and contaminants by settling of sediment, infiltration, and filtration. Most sediments settle upgradient of where the filter strip vegetation meets the contributing area.
Tile System
Tile Replacement (NRCS CP 606)	The replacement of existing tile with new to alleviate excessive sediment being carried by the existing tile system.
Alternative Tile Intakes (Perforated Risers, Gravel/rock inlets, dense pattern Tile) (NRCS CP 606)	Isolated surface depressions in agricultural fields are commonly drained with subsurface tile having surface intakes. Open intakes that are flush with the surface of the ground can provide a direct conduit for sediment and nutrients to enter the tile system, which lead to ditches, streams, and rivers. Alternative tile intakes increase sediment trapping efficiency through increased settling time and/or filtering. They can also reduce the velocity of flow into the tile inlet. Alternative tile Intakes include: Perforated risers, such as the Hickenbottom riser; Gravel (rock) inlets, with gravel to the ground surface, or with a layer of soil covering the gravel (blind inlet); Dense pattern tile within the isolated surface depression with a capacity equal to the open tile inlet it replaces; or Other variations of the above. Water quality benefits of alternative tile intakes are primarily associated with the temporary ponding of water and settling of particles before reaching a waterbody. (ABH 2012, pg. 67)
Denitrifying Bioreactor (NRCS CP 605)	Woodchips or similar carbon source are placed in an underground trench and tile water is diverted through the bioreactor to remove nitrates from subsurface drainage water.
Vegetative Subsurface Drain Outlet (Saturated Buffer) (NRCS CP 739)	A vegetative subsurface outlet provides a route for tile drainage water to seep beneath buffer areas of perennial vegetation. This process reduces peak flow rates, nitrates in tile water and increases plant uptake of nutrients.
Wetland Creation (In-line or Off-channel) (NRCS CP 656)	Constructed wetlands, sometimes called treatment wetlands, are man-made systems engineered to approximate the water cleansing process of natural wetlands. In agriculture, constructed wetlands are used to filter runoff from cropland, feedlots, aquaculture operations and agricultural processing facilities. Constructed wetlands can also provide habitat for some waterfowl, other birds, amphibians and invertebrates. Constructed wetlands are effective at reducing peak flows,settling sediment, and removing nutrients. (ABH 2012, pg. 146)
Dam (NRCS CP 402)	An artificial barrier that can impound water for one or more beneficial purposes. The purpose for a dam include the following: Reduce downstream flood damage and Create or improve habitat for fish and wildlife.
Off System
Cover Crops (NRCS CP 340)	Cover Crops as a BMP refers to the use of grasses, legumes or forbs planted to provide seasonal soil cover on cropland when the soil would otherwise be bare. In Minnesota, the cover crop is commonly rye, although oats, barley, alfalfa, buckwheat and hairy vetch are also used. The short growing season in Minnesota limits the use of cover crops although use is expanding as farmers are seeing the environmental and financial benefits of the practice. Water quality benefits of cover crops come from three processes. The first is the literal cover that the crop provides to the soil, reducing erosion from raindrop impact. The second is the potential for the cover crop to take up nutrients that would otherwise be lost from the field through surface or drainage water and the third is increasing soil infiltration. (ABH 2012, pg. 37)
Grassed Waterways (NRCS CP 412)	Grassed waterways are vegetated channels through fields that provide a means for concentrated flows to drain from a field without causing erosion. They can be installed on most fields but are especially effective in controlling gully erosion on steeper slopes. Grassed waterways are commonly used to convey runoff from terraces and diversions but are an important BMP wherever concentrated flows occur. The water quality benefits of grassed waterways improve water quality by preventing gully erosion. Additionally, the vegetative component can provide filtering and volume reduction. (ABH 2012, pg. 84)
Water and Sediment Control Basin (NRCS CP 638)	Water and sediment control basins (WASCOBs) consist of an embankment across the slope of a field or minor waterway to temporarily detain and release water through a piped outlet or through infiltration. They are constructed perpendicular to the flow direction and parallel to each other. WASCOBs are usually installed in areas where the land is relatively steep and undulating. WASCOBs are used to improve the ability to farm sloped land and to reduce erosion on farmland and waterways. WASCOBs are used to manage hydrology by controlling downstream flow rates, thereby reducing erosion. A buffer of permanent vegetation surrounding risers can help to filter sediment and pollutants. The key benefits of WASCOBs are detainingwater from contributing areas, inducing sedimentation and controlling the release of water, thereby reducing the erosive power of the water downstream. Additional benefits are settling of sediment bound pollutants and some infiltration. (ABH2012, pg. 143)
Contour Bufferstrips (NRCS CP 332)	Contour buffer strips are planted in-field and on the contour (perpendicular to the slope) and are regularly spaced between wider crop strips. As an in-field buffer conservation practice, contour buffer strips provide runoff and erosion control close to the source. Contour buffer strips, in contrast to contour stripcropping, are narrower than adjacent crop strips and are planted in permanent vegetation. Established buffer vegetation is herbaceous and dense. Contour buffer strips slow the flow of water, thereby facilitating infiltration and diffuse flow, reducing sheet and rill erosion, and reducing the transport of sediment and associated contaminants to downstream water bodies. Contour buffer strips can also provide pollutant removal to shallow groundwater flow that interacts with the buffer root zone. (ABH 2012, pg. 28)
Contour Farming (NRCS CP 330)	Contour farming entails farming along the contour such that ridges, furrows and planting are perpendicular to the slope of the land. Contour farming is an erosion control system that has the effect of changing the direction of runoff from directly downslope to across the slope. Stable outlets such as field borders and grassed waterways are necessary downstream components of contour farming. The concept of contour farming had an early beginning in the worldwide history of agricultural production, and in modern history it was one of the first practices promoted by the United States Soil Conservation Service (subsequently renamed the Natural Resources Conservation Service) when it was formed in the 1930s. Contour farming increases infiltration of rainwater and reduces sheet and rill erosion, thereby reducing soil loss and the transport of sediment and associated contaminants to downstream waterbodies. Contour farming improves the performance of downstream buffer-type practices such as contour buffer strips, terraces, contour stripcropping, cover crop, filter strips, and grassed waterways because it helps to prevent concentrated flow. Contour farming has a long history of implementation but a disproportionately sparse record of contaminant concentration reduction as a stand-alone conservation practice. (ABH 2012, pg. 33)
Conservation Cover (NRCS CP 327)	Conservation Cover is establishing and maintaining permanent vegetative cover with the intention of reducing soil erosion. Conservation cover reduces erosion and nutrient loss by changing landcover from row crop to grasses. Conservation Cover is often the result of the Conservation Reserve Program (CRP), Reinvest in Minnesota (RIM) and/or the Conservation Reserve Enhancement Program (CREP), although other programs also contribute to the implementation of Conservation Cover. Although these programs have different goals, the end result of each is the establishment of grasses on lands previously used for row crops. (ABH 2012, pg. 22)
Conservation Crop Rotations (NRCS CP 328)	The NRCS defines Conservation Crop Rotation as “growing crops in a planned sequence on the same field”. The MDA takes this definition one step further by defining it as “A system for growing several different crops in planned succession on the same field, including at least one soil-conserving crop such as perennial hay.” In Minnesota, this practice usually consists of a corn-soybean-hay rotation or a corn-soybean-small grain rotation. Crop rotations have many benefits to the producer including reduced erosion, improved soil quality, and improved wildlife habitat. The water quality effects of a conservation crop rotation occur in two ways. The first is that growing legumes and other crops can provide nitrogen credits in subsequent years, reducing fertilizer inputs and the risk of nitrate leaching. The second effect is that a year in the soil conserving crop serves to directly improve the water quality of runoff from the land by reducing erosion. (ABH 2012, pg. 26)
Conservation Tillage (NRCS CPs 329, 345, 346)	Conservation tillage is any tillage practice that leaves additional residue on the soil surface for purposes of erosion control on agricultural fields. Conservation tillage is one of the basic BMPs used on farms state-wide. Many different variations of this common practice are implemented, the specific variation selected is often based on climatic conditions and available equipment. Since 1994, the USDA has required the use of conservation measures on highly erodible land to remain eligible for program benefits. Conservation tillage is one of the easiest ways to protect erodible land with the least interruption of cropping practices. Crop residue is the most important factor effecting erosion from different tillage systems. The more residue on the land following tillage, the less erosion from the field. No-till and strip till involve planting directly into crop residue that either hasn’t been tilled at all (no-till) or has been tilled only in narrow strips (strip-till). Water quality improvements are due primarily to improved erosion control but conservation tillage can also protect water from nutrient and pesticide losses. (ABH 2012, pg. 94)
Vegetated Bufferstrips -- Filter strips (NRCS CP 393)	Filter strips are an area of vegetation planted between fields and surface waters to reduce sediment, organics, nutrients, pesticides, and other contaminants in runoff. Filter strips are one of the most common BMPs used on farms state-wide. Filter strips reduce runoff, sediments, and contaminants by settling of sediment, infiltration, and filtration. Most sediments settle upgradient of where the filter strip vegetation meets the contributing area.
Nutrient Management (NRCS CP 590)	Nutrient management is the management of the Amount, Method, and Timing of applications of fertilizers, manure, and other soil amendments. The nutrients that have the greatest impact on water quality are nitrogen (N) and phosphorus (P). Among all BMPs, nutrient management BMPs are one of the most effective ways to improve water quality because of the extent of nutrient related water quality issues. Nutrient Management is one of the most common BMPs used on farms state-wide and is recognized as a practice that can be implemented on almost every farm. The CP 590 standard the NRCS uses the 4Rs of nutrient management being, the Right source, Right rate, Right time and Right place for plant nutrient application. Excesses of both N and P can adversely affect the aquatic system, driving newwater quality standards and efforts to prevent further impairment of water bodies. N applied in agricultural fields poses a potential threat to human health when excessive levels of the nitrate form of N find their way into drinkingwater sources. Agricultural fertilizers are also a major contributor of nitrates to the Gulf of Mexico where they cause seasonal hypoxia. (ABH 2012, pg. 48)
Drainage Water Management (NRCS CAP 130, CP 587, CP 554)	Controlled drainage, sometimes referred to as drainage water management, is a practice used to control or manipulate the ground water elevation in a tile drained field. Controlled drainage is similar to traditional tile drainage except that tile outflow is intercepted by a water control structure that effectively controls the elevation of the water table in a field by adding or removing stoplogs within the structure to raise or lower the water table. Controlled drainage may be implemented as part of a new system or as part of a system retrofit. Water quality benefits attributed to controlled drainage result primarily from reductions in water yield volume which reduces the yield of nitrogen from the field.
Terrace (NRCS CP 600)	A terrace is an earthen embankment, ridge or ridge-and-channel built across a slope (on the contour) to intercept runoff water and reduce soil erosion. Terraces are usually built in a series parallel to one another, with each terrace collecting excess water from the area above. Terraces can be designed to channel excess water into grass waterways or direct it underground to drainage tile and a stable outlet. Terraces are generally used in steep-slope applications although they can be used to reduce erosion on moderate slopes as well. Terraces are primarily used as a method to reduce slope length to reduce field erosion and gully formation which should reduce sediment loading to the downstream waterway. (ABH 2012, pg. 113)