Anaham Meadows Upper Diversion Repair

In April 2018, flows in Anaham Creek were unusually high (due to snow-melt), and the T'letinqox Government (TG) reported that some of the recently rehabilitated drainage infrastructure along the creek and diversion channel was damaged. Based on information provided by the TG and subsequent site investigations by KCB, the scope of repairs is expected to include the following:

1. The eroded left bank of Anaham Creek just upstream of the Upper Diversion structure will be graded to a minimum 2H:1V slope and a filter layer placed to provide erosion protection.
2. Erosion of the banks downstream of the Upper Diversion structure will be repaired to re-establish the separation of the diversion channel and Anaham Creek by placing fill and erosion protection between the channel and creek. All the embankments downstream of the Upper Diversion will be built up wherever erosion and/or back-cutting has occurred, by placing appropriate fill, filter layers/cloth, and riprap.
3. The anchors connecting the downstream steel columns of the walkway structure to the concrete piers will be reset at the two cracked locations, by:
(a) Removing the old anchors and any compromised concrete;
(b) Setting new anchors in their correct locations, to fit the current position of the steel column bases;
(c) Setting the new anchors in new concrete, anchored to the old concrete by steel reinforcing bars, appropriately embedded into the old and new concrete; and
(d) Fixing the steel walkway columns to the new anchors.
4. The creek-side gates of the Upper Diversion structure will be repaired following a mechanical investigation.
5. The diversion channel will be excavated to have a uniformly sloped gradient from the Upper Diversion to the road crossing culvert.
6. A washed out culvert upstream of the Upper Diversion will be repaired by adding an additional culvert and armouring the road and downstream embankment to prevent future erosion or washouts.
7. Further erosion at the downstream road crossing will be mitigated by armouring the road at the crossing.
8. The right bank at the irrigation point will be rehabilitated by placing and compacting fill material, the irrigation point will be moved to the road crossing culvert, and a channel will be excavated to connect the irrigation point to the rest of the meadow.