Water Stewardship Information Sources
| ID | 14 |
|---|---|
| Citation | Alex, K., C. Louie, Z, Masters, C. Rivard-Sirois, A. Stevens and J. Squakin. 2013. Aquatic monitoring of the Okanagan River Restoration Initiative (ORRI) - Post-construction 2012. Prepared by Okanagan Nation Alliance Fisheries Department. Westbank, BC. |
| Organization | ONA |
| URL | http://www.douglaspud.org/HCP%20TC%20Documents/2013_08_26%20ONA%20-%202012%20ORRI%20Monitoring%20FINAL%20Report%20(Tributary%20Assessment%20Program).pdf |
| Abstract/Description or Keywords | The purpose of this report is to document the effectiveness of the Okanagan River Restoration Initiative (otherwise known as ORRI) works completed in 2008 and 2009. Monitoring began pre-treatment in 2008 and continued until 2012. This report summarizes the five years of study. The objectives of ORRI, set at the beginning of the project, were to: ? Objective 1: Restore natural river channel shape, meander pattern, and substrate conditions to enhance the quantity and quality of spawning and rearing habitat for Sockeye, Chinook Salmon, Steelhead/Rainbow trout, other native resident fish species and additional aquatic organisms; and ? Objective 2: Restore floodplain riparian plant communities to enhance fish and wildlife habitat, stabilize stream-banks, and improve water quality and ecosystem resilience. Highlights from the five years of monitoring data (2008-2012) include: ? Desired spawning-flow Froude numbers achieved during construction in Phase I remained within the range preferred by salmon even after changes in the bed due to natural sediment transport processes during subsequent freshets. ? Pool and riffle habitats continue to dominate the Phase I restoration area, and the channel configuration is self-sustaining for spawning salmon needs even though there has been bedload movement, gravel bar creation, and pool depth changes,. ? During the 2011 freshet, the newly connected ORRI floodplain was inundated with water for 3-4 weeks; observed in just over 1/3 of the floodplain area. ? Post-treatment, the number of fish habitat features such as large woody debris (LWD) increased from natural transport and was sustained. ? Total coverage of all macrophyte species was reduced, the proportion of introduced invasive macrophyte species was reduced, and native macrophyte species diversity increased. ? Pre-treatment, no salmonids were documented during snorkel surveys; however, post-treatment snorkel surveys documented Rainbow Trout in Phase I in all three years from 2010 - 2012. ? The proportion of Sockeye spawners in Phase I increased over Phase II, and continued increase over pre-treatment conditions for Phase I. ? Low egg-incubation survival was an issue in the pre-treatment ORRI sites, but drastically improved in Phase I post-treatment with survival rates similar to those measured in the natural reaches. ? Spawning substrate gravel sizes changed between post-treatment 2009 and 2012 becoming more diverse after the two freshets of 2011 and 2012. |
| Information Type | report |
| Regional Watershed | Okanagan |
| Sub-watershed if known | |
| Aquifer # | |
| Comments | |
| Project status | ongoing |
| Contact Name | Kari Alex |
| Contact Email | [email protected] |