US Army Corps of Engineers
Walla Walla District

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Regional General Permits

Regional General Permits (RGPs) are limited to activities and projects within the Walla Walla District Regulatory Division boundaries.

RGPs authorize activities that have minimal individual and cumulative impacts. RGPs are issued for a period of five (5) years and automatically expire unless the District reissues that specific RGP.

Most RGPs require written verification from the Corps of Engineers prior to the beginning of work activity. Carefully review the RGP permit to ensure your activity and/or project complies with terms and conditions. Follow the authorization procedures as outlined in the General Permit text and send required information to the appropriate field office. 

Current Regional General Permits

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Issued:  September 20, 2016
Expires: September 20, 2021

RGP-E authorizes certain work activities in waters of the United States, including wetlands within the State of Idaho. Work activities are only authorized for temporary work and/or discharge of dredged or fill material associated with an emergency condition. These activities will occur to restore, repair, and/or stabilize features that have been damaged, destroyed, or are in imminent danger of failing. 

The RGP-E is restricted to only those activities necessary during the emergency to prevent the loss of life, significant loss of property, or economic hardship.

RGP-E Permit                Water Quality Certification

Issued:  April 2, 2015

Expires: April 1, 2020

Permit authorizes specific work activities in Pend Oreille Lake and Pend Oreille River, as outlined in the RGP-27 permit.  Separate authorization and/or approvals may be required by the State of Idaho Department of Lands (IDL) and/or the State of Idaho Department of Water Resources (IDWR).

Authorized structures include:

  • Piers
    • Floating Docks
      • Mooring Piles
        • Mooring Buoys 
          • Portable Boat Lift Stations                     
            • Small Diameter Waterline Intakes 


RGP-27 Permit                   Permit Area (Map)                     Structures Authorized

Water Quality Certification              Biological Opinion


Regional Guidance

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Click here to expand contentClick here to collapse content  Liquefied Natural Gas Projects (LNG) 

In order to ensure that proposed liquefied natural gas (LNG) projects are being reviewed consistently and in accordance with reference documents and other laws and regulations, as applicable, Headquarters U.S. Army Corps of Engineers has developed regulatory standard operating procedures for processing LNG projects (see full text for details). 

Click here to expand contentClick here to collapse content  RGL 07-02: Exemption for Irrigation, Construction, Maintenance

This RGL addresses statutory exemptions for both irrigation and drainage ditches.  The following terms are defined for purposes of Subsection 404(f): irrigation ditch, drainage ditch, construction, and maintenance. This document also provides a framework for determining the applicability of the exemptions and the recapture provision. (See Figure 1).  While providing greater clarity, both the framework and the definitions are consistent with the agencies’ current practice in interpreting the Section 404(f) exemption.

RGL 07-02 supercedes RGL 87-07, which addresses the Section 404(f)(1)(C) Statutory Exemption for Drainage Ditch Maintenance.

Click here to expand contentClick here to collapse content  Bioengineering Techniques for State of Idaho
Bioengineering is the combination of biological, mechanical, and ecological concepts to control erosion and stabilize soil through the use of vegetation or a combination of vegetation and construction materials.

Willow Clump Plantings:  a streambank soil bioengineering technique used when large stands of willows are available in the project area; results are a shorter establishment period, lower rate of failure and faster protection of site

Streambank Bioengineering Guide:  a publication written to provide guidance for streambank bioengineering, increasing awareness of streams and riparian areas, their importance and their interconnectedness with other resources

Click here to expand contentClick here to collapse content  Headwaters, Inc. v. Talent Irrigation District, 243 F.3d 526 (9th Cir. 2001)
“We view Headwaters, Inc. v. Talent Irrigation District, 243 F.3d 526 (9th Cir. 2001) as binding on the U.S. Army Corps of Engineers, Northwestern Division, in the geographic jurisdiction of the U.S. Court of Appeals for the Ninth Circuit.  In that case, the court held that irrigation canals that receive water from natural streams and lakes, and divert water to streams and creeks, are connected as "tributaries" to those other waters.  The Ninth Circuit further held that a "stream which contributes its flow to a larger stream or other body of water is a tributary. . . . As tributaries, the canals are 'waters of the United States,' and are subject to the CWA and its permit requirement." Headwaters, 243 F.3d at 533.  Moreover, the court held that, "Even tributaries that flow intermittently are 'waters of the United States.'" Id. at 534. Corps of Engineers regulations at 33 C.F.R. § 328.3(a)(5) assert Clean Water Act jurisdiction over all tributaries to other jurisdictional waters of the United States.  In factual situations where the Headwaters precedent applies, it would supercede any contrary conclusion that might be drawn from previous Corps of Engineers policy statements regarding ditches.” 
Click here to expand contentClick here to collapse content  Regulatory Guidance Letters (RGLs)
Regulatory Guidance Letters (RGLs) were developed by the Corps as a system to organize and track written guidance issued to its field agencies.  RGL’s are normally issued as a result of evolving policy; judicial decisions and changes to the Corps regulations or another agency’s regulations which affect the permit program.  RGL’s are used only to interpret or clarify existing Regulatory Program policy, but do provide mandatory guidance to the Corps district offices.

RGL’s are sequentially numbered and expire on a specified date.  However, unless superseded by specific provisions of subsequently issued regulations or RGL’s, the guidance provided in RGL’s generally remains valid after the expiration date.  The Corps incorporates most of the guidance provided by RGL’s whenever it revises its permit regulations.