For more information on the Hydraulic Permit Application (HPA) Program, please contact:
WDFW Habitat Program
(360) 902-2534


What Constitutes Complete Plans and Specifications for a Hydraulic Project Approval (HPA)?
For more information, please see HPA Frequently Asked Questions

General Plans for Overall Project Complete Plans and Specifications
for Work Waterward of OHWL/MHHW
Complete Plans and Specifications
for the Proper Protection of Fish Life

We need sufficient detail to accurately know:

  • What it is you want to do; what is the size, scale and scope of the project; include dimensions and accurate plan and cross-view drawings of the project, etc.; and
  • Where is the work going to occur; what is the project’s location; include a vicinity map and other drawings that show the project in relationship to the ordinary high water line1 (freshwater) and the mean higher high water2 line (saltwater), the channel migration zone3 and the 100-year floodplain4.

We need sufficient detail to fully understand what is being proposed so we can review the project without the need for additional information from you:

  • How do you plan to do the work?
  • When do you want to do the work?
  • What equipment will you use and how will you use that equipment?
  • Will work be sequenced? If so, how?
  • Are you under timing constraints for any part, or the entire project?
  • Will explosives be used?

While WDFW will determine what is needed for proper protection of fish life, we still need to know what measures you plan to use to avoid or reduce adverse impacts from your project. The standard of protection that we use is “no net loss5.” At a minimum, please address these questions:

  • How do you plan to control sediment delivery and erosion resulting from the project?
  • How will you address potential oil or gasoline spills or leakages that might occur from equipment use?
  • If in-water work is to occur, what method(s) will you use to temporarily divert the water from your work area?
  • How do you propose to keep fish life out of the work area?
  • Do you plan to remove riparian vegetation6, and if so, what is your plan to replace that vegetation?
  • Will heavy equipment be operated below the OHWL or MHHW; will equipment be staged on the bank or some structure, or will it work from within the water?
  • Could your project affect fish passage once completed, and if so, how do you plan to ensure fish passage is not impeded?
  • Could your project block light penetration into the water, and if so, how will you reduce that blockage?
1 Ordinary high water line (OHWL) = the mark on the shores of all waters that will be found by examining the bed and banks and ascertaining where the presence and action of waters are so common and usual and so long continued in ordinary years, as to mark upon the soil or vegetation a character distinct from that of the abutting upland: Provided, That in any area where the ordinary high water line cannot be found the ordinary high water line adjoining saltwater shall be the line of mean higher high water and the ordinary high water line adjoining freshwater shall be the elevation of the mean annual flood (Hydraulic Code Rules, WAC 220-110-020 (57)).

2 Mean higher high water (MHHW) = the tidal elevation obtained by averaging each day's highest tide at a particular location over a period of nineteen years. It is measured from the MLLW = 0.0 tidal elevation (Hydraulic Code Rules, WAC 220-110-020 (49)).

3 Channel migration zone = the area where the active channel of a stream is prone to movement over time (Floodplains and Channel Migration Zones, Jerry Gorseline, WA Environmental Council, 3/28/01); = the area along a river within which the channel(s) can be reasonably predicted to migrate over time as a result of natural and normally occurring hydrological and related processes when considered with the characteristics of the river and its surroundings (Shoreline Management Act rule, WAC 173-26-020 (6)).

4 100-year floodplain = that land area susceptible to inundation with a one percent chance of being equaled or exceeded in any given year. The limit of this are shall be based upon flood ordinance regulation maps or a reasonable method which meets the objectives of the act [Shoreline Management Act] (Shoreline Management Act rule, WAC 173-26-020 (15)); = (1) Area adjoining a water body that becomes inundated during periods of overbank flooding and that is given rigorous legal definition in regulatory programs. (2) Land beyond a stream channel that forms the perimeter for the maximum probability flood. (3) Strip of land bordering a stream that is formed by substrate deposition. (4) Deposit of alluvium that covers a valley flat from lateral erosion of meandering streams and rivers (Glossary of Aquatic Habitat Inventory Terminology, Neil B. Armantrout, American Fisheries Society, 1998).

5 No-net-loss = (a) Avoidance or mitigation of adverse impacts to fish life; or (b) Avoidance or mitigation of net loss of habitat functions necessary to sustain fish life; or (c) Avoidance or mitigation of loss of area by habitat type. Mitigation to achieve no-net-loss should benefit those organisms being impacted (WAC 220-110-020 (56).

6 Riparian vegetation = vegetation growing on or near the banks of a stream or other water body that is more dependent on water than vegetation that is found further upslope (Glossary of Aquatic Habitat Inventory Terminology, Neil B. Armantrout, American Fisheries Society, 1998).