NRCS Practice Standard: Underground Outlet (620)

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NRCS Practice Standard: Underground Outlet (620)

About the Company:

The Natural Resources Conservation Service (NRCS) is the US Department of Agriculture (USDA)’s primary private lands conservation agency. The NRCS helps producers protect and conserve natural resources on private lands through voluntary conservation programs. Through Practice Standards and technical guides, the NRCS provides information about the conservation, energy resources, and provides personalized advice to individual producers.

The NRCS’ Environmental Quality Incentives Program (EQIP) provides technical and financial assistance to producers as they implement NRCS Conservation Practice Standards.

Technical guides used in each field office are localized so that they apply specifically to the geographic area for which they are prepared. Thus, while national guidelines have been provided as a framework for each standard, each state has adopted and modified the conservation practice standards to suit their individual landscape.

To find a local NRCS Service center click here.

To find the specific guideline for each state click here.

About the Solution:

Underground Outlet - Riser (620)

A conduit or system of conduits installed beneath the ground surface to convey surface water to a suitable outlet.

Practice Information

The purpose of the underground outlet is to carry excess surface water to a suitable outlet from terraces, water and sediment control basins, diversions, waterways, surface drains, or other similar practices without causing damage by concentrated flow erosion or flooding and ponding. An underground outlet can be installed when surface outlets are impractical because of stability problems, climatic conditions, land use, farmability, or equipment traffic. An underground outlet can be used as the only outlet for a structure or practice or it may be used in combination with other types of outlets.

The conduit for an underground outlet can be either solid or perforated pipe depending on the site-specific design. The inlet to an underground outlet can be constructed of many different types of materials but the most common are heavy duty perforated plastic risers. The outlet must have a section of solid heavy-duty pipe and may have a headwall. The underground outlet must outlet into a stable watercourse that is protected from erosion caused by flows from the underground outlet. Both the inlet and outlet of an underground outlet should be protected from the entry of small animals. The outlet animal guard should be installed so that it does not impede flow from the underground outlet.

Underground outlets can provide a direct conduit to receiving water for contaminated runoff from cropland. Underground outlets and the accompanying structures or practices should be installed as part of a resource management plan that addresses issues such as nutrient and pest management, residue management, and filter areas.

Common Associated Practices

NRCS Conservation Practice Standard (CPS) Underground Outlet (Code 620) is commonly applied with other conservation practices such as:

  • Terrace (Code 600)
  • Grassed Waterway (Code 412)
  • Water and Sediment Control Basin (Code 638)
  • Diversion (Code 362)
  • Roof Runoff Structure (Code 558)
  • Critical Area Planting (Code 342)

    To view the national NRCS standard Underground Outlet please click here.

  • Natural Resources Conservation Service, US Department of Agriculture 1400 Independence Ave., S.W. Washington, DC United States 1-833-ONE-USDA Visit Company Website

    Solution Type

    • General Support and Other


    • Others


    • Other


    • Storage

    To view additional information about this vendor, click below.

    Solution Strengths, Weaknesses and Critical Indicators

    NOTE: There are multiple technologies that are used as part of integrated manure management systems and yet are not manure management types on their own. The impact of these technologies on their own would be minimal or very difficult to quantify.

    General Support & Other:

    • Can be an integral part of many manure management systems
    • Most projects have at least some equipment that supports operations of the main technology
    • This technology is not evaluated on its own, the NEAT Matrix for this technology is neutral unless utilized with other technologies.

    Newtrient Comments/Opinions:

    Newtrient is using the USDA-NRCS conservation practice standards as tools to assist dairy producers in understanding the standards and how they can be used to address resources concerns.

    To establish a Practice Standard a system or practice must be thoroughly vetted, approved, and standardized by the USDA at the federal and state level. These conservation practices have been developed to address various environmental resource concerns. Newtrient has developed a 9-point scoring process for ranking additives, practices, services, and technologies for the dairy industry. Recognizing the rigorous approval procedure used during the development of the NRCS Practice Standards, many of them score very highly and are worthy of consideration on any dairy where they apply.

    The information provided here is a summary of the selected conservation practices. For up to date and detailed information related to the full Practice Standards, please see the USDA NRCS website, linked above.

    Newtrient 9-Point Scoring Rating

    View the Scoring Page

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