July 24th, 2015 Pre-Project Flight before PALS installation with mostly shallow, fast water habitat (riffles)
September 10th, 2015 Post-Project Flight after Post Assisted Log Structures installation and structures are slowing water habitat and PALS may have increased ground water storage by holding water behind structures. The floodplain area has better hyporeic connection and has greened up substantially in the month after project implementation.
Alpowa Post Assisted Log Structures
Over the last two years the Palouse CD, in concert with the Asotin County Public Utility District, landowners on Alpowa Creek, and a partnership with the Pomeroy Conservation District implemented a project resulting in 202 Post Assisted Log Structures for ESA Listed steelhead being installed. This project was funded by the Salmon Recovery Funding Board with the expectation that the project would result in the increase of pool quality and quantity in addition to the increase of wood for complex habitat and floodplain connection. These habitat benefits are realized both by steelhead and aquatic species and local landowners.
To date, the 202 structures resulted in 150 pools deeper than one foot and the addition of 457 pieces of wood which were donated by the US Forest Service Pomeroy Ranger District. From the photos you can see that Alpowa is a small, spring feed stream and maintains a mean flow of 9 to 11 cubic feet per second. Over the last seven years the Washington Department of Fish and Wildlife has document more than 1,134 natural origin steelhead utilizing this system.
The pre-project photo was taken on July 24th and the post-project completion photo was taken on September 10, 2015. The only change to occur to this stretch of the stream other than time in these two photos are the installation of instream post assisted log structures. There was no significant rainfall or increase in base flows during this timeframe for this section of stream.
Project Lead and Implementer was Brad Johnson of the Palosue CD.