WATERSHED, SOIL, AND AIR PROJECT PROPOSAL USDA Forest Service, Technology & Development Program 09-15
Project Name or Title:	Post Fire Grade Control Structure Development and Testing
Submitted by (your name):	Bruce Sims and Dick Karsky
Unit name and address:	MTDC/Northern Region, 5785 Highway 10 West, Missoula, MT 59808
Telephone:	Dick 406-329-3921 Bruce 406-329-3447
IBM or Internet Address:	rkarsky@fs.fed.us and bsims@fs.fed.us
Date:	March 11, 2008
OVERALL OBJECTIVES/PROBLEM STATEMENT (Describe the problem, how the work is currently being done, and why improvement is needed.)
After wildfires problems exists in controlling erosion and channelization in small streams. Review of recent fires shows that large amounts of sediment are being yielded from ephemeral channels following convectional thunderstorms that occur within 1 to 3 years of the fire. Structures or devices to reduce this occurrence are desirable to prevent the erosion and silting of stream beds downstream from the burned over area. Some of the current methods used such as check dams can increase undercutting and not provide any erosion control.
PROPOSED TECHNOLOGY & DEVELOPMENT WORK (Describe your concept of the end product, i.e., a new equipment design, a video production, a guide, etc.)
This proposal requests improvement and testing of two alternative grade control structures. These structures are envisioned as grade control to minimize channel down cutting. They are not traditional check dams and will be constructed with very little weir height. Two designs have been preliminarily tested: 1) In the fall of 2003, two grade control devices were installed by hand in Lyon’s Cr near Missoula after a fire passed through the area. The devices were monitored for 2 seasons, show promise in reducing channelization and erosion but the test was a limited one, and a larger scale test needs to be completed to verify that the concept will work in different conditions and on larger streams. A method needs to be developed to install these grade control devices on a operational basis. This project would develop a more efficient operational method to install the grade stakes and investigate alternate configurations of the grade control with different spacing between the devices as a means to reduce the installation time and cost. Rough cut 2"x4" sharpened rough cut lumber was driven into the ground side by side until the draw is spanned and then the 2" x 4"s are cut off at or near grade (see fig.1) Figure 1 – Rough Cut 2” x 4” Grade Control Structures 2) Twenty five of the T-post and wire mesh structures were established in 1980 following an operational fire on the Siskiyou National Forest. The severely burned watershed size was approximately 60 acres. Wire mesh supported by 4 T-posts was stretched across the channel and rapped up channel to create a structure that would hold itself in place (see figure 2).
POTENTIAL BENEFITS (Describe how this project will improve safety, reduce cost, save time, increase efficiency, provide improved resource management, or increase customer satisfaction.) If these grade control devices perform as they appear to, this technique will give BAER personnel another tool to reduce erosion and silting of stream beds. The project may result in acceptable low cost post fire grade control structures that would reduce channel down cutting and subsequent hill slope adjustment to the lowered base levels. If successful, post fire sediment related impacts to downstream aquatic habitat will be reduced. In areas where channel down cutting would have undermined hill slopes the effects may be very large.

Figure 2 – T-post and Wire Mesh Grade Control Structures