Huwer Bank Stabilization and Riparian Fencing Project: 06.SHU.01

Transcription

1 Huwer Bank Stabilization and Riparian Fencing Project: 06.SHU.01 Prepared for: Howard and Joe Huwer Prepared by: Tom Minor Prepared with the financial support of: B.C. Hydro Bridge Coastal Fish and Wildlife Restoration Program

2 Executive Summary The Huwer Bank Stabilization and Riparian Fencing Project is jointly funded by BC Hydro Bridge Coastal Fish and Wildlife Restoration Program (BCRP), the Environmental Farm Plan (EFP), Fisheries and Oceans Canada (DFO), the B.C Cattleman s Association and the landowners, Joe and Howard Huwer. The original goal of the project was to protect 450 m of stream bank and old growth cedar riparian area while increasing instream habitat values by building 30 habitat structures. These structures use a combination of large woody debris, brushy material and rock to reduce the erosive force of the river near the bank and while providing instream and above-stream cover to improve fish habitat. The project resulted in the construction of 71 habitat structures covering approximately 950 m of bank. The increase in the number of structures was partially due to the development of rock on-site and partially by an increase proportion of the landowner s contribution. i

3 Table of Contents List of Figures... ii Introduction... 1 Goals and Objectives... 1 Study Area... 2 Methods... 5 Results... 7 Discussion Recommendations Acknowledgements References Appendices I. Financial Statement II. Performance Measures Actual Outcomes III. Confirmation of BCRP Recognition List of Figures Figure 1: Aerial view of project site... 2 Figure 2: Location of project... 3 Figure 3: Location of bank work... 4 Figure 4: Hawthorn being loaded for bank work... 7 Figure 5: Eroding bank before treatment... 9 Figure 6: Treated bank... 9 Figure 7: Planting frozen shrubs with excavator Figure 8: Planted bank Figure 9: Fence lines ii

4 Introduction Four years ago, the Huwers began to do bank stabilization work on the Shuswap River upstream of their Bailey bridge to prevent erosion around the left bank bridge abutments. The Huwers wanted the bank work to improve fish habitat values as well as prevent bank erosion. Lee Hesketh was hired to design and supervise the work. Habitat structures using whole trees and shrubs as well as large rock were constructed along 750 m of bank. The structures provide lowand high-water refuge for juveniles as well as bank stability. By adding brushy material to the structures that dampen the current close to be bank and providing dense in-stream and abovestream cover. They also have helped to maintained pool holding areas with cover for adults by accelerating and converging the current around the root wads and logs. After the success of this first project, the Huwers wanted to continue this work upstream. Shifting river channels has been eroding the banks on several corners and recently formed logjams have accelerated the process. This property has high habitat values that include a 2 km groundwater-fed pond and creek complex and 2 km of riverbank. This riverine riparian area contains one of the last stands of mature cedar on the middle Shuswap River. Typical of Interior old growth cedar, these trees are largely shells with cavities that provide nesting and denning sites for a variety of birds and mammals. Bank erosion and the slow downstream migration of meanders are natural processes. The toppled trees provide instream cover for fish and often cause scouring and pool habitat. This project used bank stabilization techniques that incorporates the trees that have recently fallen in and adds additional large woody debris (LWD) to enhance fish and wildlife habitat. By building the habitat structures, the erosion is reduced, the old growth riparian trees preserved, holding pools maintained and created and brushy in-stream cover added for juvenile refuge areas. The Huwer family participated in four of the five major BC Hydro and BCRP funded projects in the area. The Ireland Creek Side Channel (02.SH.36) and the Huwer Groundwater Complex (05.SH.02) were built on Huwer properties. The Huwers were one of the seven landowners involved with Procter Channel (02.SH.35). The Limmer/Lang Channel (B.C. Hydro) also borders Huwer properties and required their cooperation. Their previous involvement with BCRP projects prompted them to apply for funding to help complete this work. The Huwer Bank Stabilization and Riparian Fencing Project is a jointly funded project by BC Hydro Bridge Coastal Fish and Wildlife Restoration Program (BCRP), the Environmental Farm Plan (EFP), Fisheries and Oceans Canada (DFO), the B.C Cattleman s Association and the landowners, Joe and Howard Huwer. Goals and Objectives The goal of this project was to protect the cedar riparian area on the Huwer property and improve fish habitat by building 44 habitat structures along 450 m of the left bank of the Shuswap River and building 4 km of riparian fence. 1

5 Study Area Lawrence Road, off Mabel Lake Road, 20 kms north of Lumby, UTM , to , , approximately 8 km downstream of the Wilsey Dam on the Middle Shuswap River and 6 km downstream of Bessette Creek, the Middle Shuswap River s main tributary. This section of the Shuswap River is one of the most heavily utilized spawning areas on the Middle Shuswap River (Arc 2001). The river is braided and contained in one channel for only about 1/3 of its length along the Huwer property. Logjams have contributed to creation of the various channels and lateral movement over the past few years (Figure 2). The Huwer property consists of 640 acres of which approximately 100 acres are cleared. The uncleared portion of the property is cedar/spruce/cottonwood forest in the floodplain (el. 408 m) while the hillside is Douglas fir. Most on the land is on the west side of the river and is accessible only by their Bailey bridge. The land is used for summer pasture and a winter-feeding area for cattle. Extent of bank work Figure 1: The bank stabilization began at upper (downstream) area and ended at the lower (upstream) arrow. This area is roughly 1200 m long with approximately 950 m treated. The 3600m riparian fence will exclude livestock from the riverbank and pond area. 2

6 06SHU01 March 14, 2007 Huwer Project Wilsey Dam Figure 2: The project is located on the Shuswap River 8 km downstream of Wilsey Dam in the Southern Interior. 3

7 06SHU01 March 14, 2007 Huwer Bridge Start of existing bank work Project Area End of existing bankwork Start of new work Shuswap River Shuswap River Mabel Lake Road End of new work Bessette Creek Wilsey Dam Side Channel widened during 2006 freshet Figure 3: Location of Huwer property and bank work. Lumby 41

8 Methods A work permit were obtained on August 30 (Ministry of Environment File #A35753). Work began in early November, developing rock on the Huwer property. In mid-november, access was developed to the drier areas. After there was sufficient frost in the ground to allow passage of loaded dump trucks, access to the wetter sites was cleared. Material Collection Rock development began in October. As the river access was opened, some rock was delivered to each habitat structure location. Because of the lack of space between trees, only one or two loads could be placed per structure. The amount of wood and brush that could be placed before excavation work began was also limited. Three excavators were used. A John Deere 150 developed and loaded rock from two pits on the Huwer property. Two Hitachi 120 excavators were used to build the habitat structures, for placing extra woody debris and for re-planting the shrubs. Two dump trucks were employed for delivering rock and some woody material. Because there was no hauling on or across public roads, full-length trees and shrubs could be hauled with the dump trucks (Figure 4). One of the trucks belongs to the landowner and was counted as in-kind. A 360 Timberjack line skidder was used to collect wood (mostly windfall and old logging debris) from the hillside and pasture areas of the Huwer property and skid the material to the work sites. Douglas fir, hemlock and cedar were the preferred species and most often used especially for the larger trees because of their longevity. Whole hawthorn shrubs from recent land clearing were also used. The hawthorn is dense, very strong and long lasting. When used in the habitat structures, the thorns tend to collect other material that adds to the dampening effect of the structures. The skidder was also used to move some of the frozen shrubs from the fence line to the riverside for planting. Habitat Structures Location of each habitat structure was marked with 1 m wooden stakes and flagging in June. Each structure is placed at a location where it will be most effective in deflecting the flow away from the bank. The structure farthest upstream was placed 10 m downstream of a bedrock outcrop that formed the left bank. Subsequent structures were placed an average of 15 m apart so each structure is at the downstream end of the lee of the structure immediately upstream.. There was some variation in distance between structures due to the spacing of the cedar trees growing at the edge of the bank. The structures were placed to minimize disturbance to the roots of these trees. The large woody debris (LWD) of the main structure deflects the thalweg away from the bank while the brushy material placed in between the larger wood and on the downstream end of the structure reduces the erosive force or the water around the structure and dampens the eddy effect caused by the deflection. Before a structure was placed, the area was examined for redds. All work was completed without damage to redd sites either directly or by creating a souring action or other flow alteration that would affect redds downstream of the structure. At the start of the excavation work, the bank overhang was pulled back. The vegetation and organic layer of soil covering the work area peeled back and removed in such a manner as to 5

9 preserve as much of the root structure as possible and placed to the side for later re-use. This material was replaced over the disturbed area after construction is complete. A trench was excavated in the riverbank perpendicular to the river to approximately 0.3 m above the water level. The length of the trench was determined by the LWD to be placed in the bank. Generally, one-third to one-half the length of the log or tree was buried in the bank. The trench excavation is continued below water level but with a narrow berm maintained between water and trench to isolate the work area from the river and prevent any release of silt. Once below the waterline, s the excavator removed the saturated material slowly, so as not to create a vacuum that would cause the berm to fail. Once the trench is excavated to slightly below the streambed level, large angular rock was placed. The large rocks are placed individually for a tight fit. Smaller rock was packed between the large rocks to form a tight matrix and compacted with the bucket. This base layer brought the trench back up to water level. The rock base below streambed level will reduce the risk of future undercutting. The width of the trench was generally 2 m wide depending upon the material to be placed, the cohesiveness of bank material, depth of water and height of bank. The bank material was sufficiently fine that seepage was not a problem here. However, the trench was backfilled from the river end first so that any seepage could be removed with the bucket from the end of the trench farthest from the river before placing the next bucketful of rock. This prevented any silty water displaced from the trench from entering into the river. A pump was kept on hand in case the bank and berm material was porous and seepage became a problem. Enough discharge hose was on hand so that the silty water could be pumped far enough so as not to flow back to the river or muddy the work site. Once a base was placed level with the waterline, the first layer of smaller trees and/or logs and brush clumps were placed with tops extending out over water. The angle of material varied with the desired area of influence and length of material but generally about 40 o off the downstream bank to 40 o off the upstream bank. The brushy material was fanned out to dampen the stream energy around the base of the structure. The brushy material used was often the tops of coniferous trees left from recent logging on the hillside. Some longer shrubs like hawthorn were place so the tops hung in the water at the downstream end of the structure to dampen the eddy effect of the LWD. A mixture of rock and excavated soil was packed in with the woody material to fill the voids and compacted with the bucket. Larger logs/trees ( m butt diameter x 5 7 m) were placed over top of the first layer and large rock placed around the end of the logs and along the edge of bank. This LWD and the large rock used to secure them are the main anchors that will hold the structure in place. Large rock is placed as ballast. The rock face at the water will prevent erosion of the disturbed material along water s edge and movement of the anchor log. Smaller rock and the remainder of the bank material were compacted with the bucket around the logs and ballast rock. Finally, the topsoil, sod and shrubs were placed over top. Trees that had recently fallen into the river and were still adjacent to the bank were secured in place by placing the larger logs over the trunk of the tree behind the root wad and brushy material in the gap between the root and the bank. Fencing The fence line was cleared after the ground was frozen with a Case 1150E cat, provided by the landowner. Larger shrubs were lifted and replanted with the 120 excavator. Posts are being driven with a Hitachi 120 excavator. The fence will be a six strand fence with four strands of 6

10 high tensile wire and two strands of barbed wire. The two center strands of barbed wire discourage cattle from pushing against the fence or putting their heads through the fence to graze, often loosening the wire. The two upper and lower strands of high tensile wire reduce the potential to injure wild life jumping over or slipping under the fence. Planting The existing large shrubs such as Douglas maple (Acer glabrum), mountain alder (Alnus incana ssp tenuifolia), and beaked hazelnut (Corylus cornuta) found along the riverbank and fence line were lifted with the excavator and placed to the side during site preparation. These shrubs were replanted after the bank work was done. Grass seeding was done during the last week of March. Additional planting of live willow stakes will be done in April. The EFP and landowner are sharing the cost of planting. Results Seventy-one habitat structures were built covering approximately 950 m of bank. Approximately 450 loads of rock (3600 m 3 ) were loaded from the two pits developed on the Huwer property. Both the rock and woody material were developed on the Huwer property. Cycle time was about 15 minutes. The majority of the wood and brushy material was skidded to the work site and is harder to quantify. Roughly two truckloads (Figure 5) were used per 3 habitat structures. Figure 4: Hawthorne being loaded into the demolition-style box of one of the dump trucks to be taken to the river on the Huwer property Approximately 1700 m of the riparian fence line is through un-cleared land and required some brushing and leveling. Another 1900 m is at the edge cleared fields on the outside of the existing riparian band. 7

11 Figure 5: A higher than average runoff and shift in the river accelerated the rate of erosion. Some of the recently fallen trees were incorporated into the bank work. Figure 6: Seventy-one habitat structures were built and the bank re-sloped along approximately 1000 m of bank. Additional woody debris was placed along top of bank for wildlife cover and to create microclimates for spring planting of willow cuttings and spruce seedlings. 8

12 Figure 7: Shrubs were removed for construction, stored out of the way and later replanted with the excavators. Fifteen to twenty-five centimeters of frost in the ground allowed the shrubs to be lifted easily with most the root mass in tact. The frozen dirt clump could easily be handled later for re-planting. The area will be heavily grass seeded and planted with live willow stakes. Figure 8: Shrubs removed for construction were replaced along the top of bank. 9

13 Existing fence New fence Bank work Figure 9: The new fence will protect 3600 m of riparian area along the river and pond. 10

14 Discussion This project was jointly funded by BC Hydro Bridge Coastal Fish and Wildlife Restoration Program (BCRP), the Environmental Farm Plan (EFP), Fisheries and Oceans Canada (DFO), the B.C Cattleman s Association and the landowners, Joe and Howard Huwer. BCRP portion of the funding was dedicated largely to the material and construction of the habitat structures. The work that was originally planned included 30 habitat structures over 430 m. The additional work was done because shifts in the river in the spring of 2006 that increased the rate of erosion on the upstream end of the Huwer property. The additional bank that was treated is on a side channel where erosion was occurring at a slower rate than the rest of the property. It was thought that this area wouldn t have to be treated for at least several years. However, the loss of an upstream logjam caused the side channel to widen and increased the portion of the river s flow into the side channel, accelerating the rate of erosion. The landowner covered the additional costs for construction. The cost of the additional work were offset to some degree by developing all the construction material on site. The cost of developing the rock was offset by getting the rock as in-kind and the shorter haul cycle for the trucks. The EFP will provide some additional funding for the extra planting and fencing. The treated area now extends upstream to a hard point where bedrock will prevent any further lateral movement of the channel. This will prevent upstream erosion from working down and around the habitat structures There was an abundance woody and brushy material on the property for construction materials. A windstorm last summer left blowdown scattered around the property. Clearing debris for access to the riverbank and for the fence line also provided woody and brushy material. There was also some recent clearing around one of the fields provided hawthorn and other shrubs to incorporate into the structures. The bank work for this project was originally scheduled for August but was delayed when it was determined that the decking of the Huwer s Bailey bridge would have to be replaced before rock could be hauled across it. While the landowner was trying to source affordable decking, the problem was circumvented by developing rock on the Huwer property so that the bridge didn t have to be used. The cost of developing the rock was offset by not having to purchase rock and by the shorter cycle time. The trucks were able to make a round trip in minutes as opposed to 30 to 45 minutes from the nearest quarry. The second cause for delay was the access to the river remained too wet in many places to haul truckloads of rock without hauling in gravel first. This would have been expensive and would have created a more intrusive and permanent roadway than was wanted. This problem was solved by waiting for sufficient frost to be able to haul materials with only minor clearing. Waiting for cold weather had additional benefits. The Shuswap River is typically at its lowest level during the winter months with less threat of surges due to rain. Low water is critical for installing the habitat structures at the proper depth without causing siltation or the extensive use of pumps and additional isolation techniques. Once the ground is frozen, disturbance to the soil and root structure of the vegetation is minimized. Shrubs along the access routes, for example, can be cut off at ground level and the root systems left intact. With 15 to 25 cm of frost, the shrubs that had to be removed for 11

15 construction could be lifted with the excavator and stored nearby with the frozen root balls intact. The frost also protects the smaller shrubs and non-woody vegetation from being destroyed. The above ground material is removed during work but the root systems remain intact and the plants quickly re-grow in spring. Another change to the original plan was the placement of extra woody debris along the top of bank in the treatment area. This was done because of the extensive area of the work. While the entire treatment area is to be seeded and planted with deciduous trees, the added debris will off immediate cover for wildlife along the river. It will also allow for planting trees in protected pockets. There was a delay in the delivery of the fencing materials for the project. The fencing is expected to be completed in April. The EFP is covering part of the cost of clearing for the fence and erecting the fence. As soon as the fencing is completed, willows stakes will be planted and protected with vole guards and wire. Recommendations The bank work should be inspected during and after freshet for stability. Any adjustments can be made during the August in-stream work window with proper notification. Re-vegetation should be checked after freshet and re-seeding done in any areas where the earlier seeding didn t take on the bank slope. Acknowledgements This project was made possible with funding from BC Hydro Bridge Coastal Fish and Wildlife Restoration Program, the Environmental Farm Plan, Fisheries and Oceans Canada and the B.C Cattleman s Association. References Arc Environmental Ltd., 2001, Shuswap River Fish/Aquatic Information Review. 12

16 06SHU01 Appendix I March 14, 2007 Project # 06SH01 Financial Statement Form Budget Actual BCRP Other BCRP Other INCOME Total Income by Source $ 64,145 $ 73,199 $ 64,145 $ 130,099* Grand Total Income $ 137,344 $ 194,244* EXPENSES Project Pesonnel Wages $ - $ 7,776 $ - ongoing* Consultant Fees $ 2,540 $ 6,360 $ 2,520 $ 3,150* Contractors Skidder $ 1,365 $ - $ 1,365 $ 5,980 Truck $ 420 $ - $ 420 $ 420 Excavator $ 4,500 $ 12,500 $ 4,500 $ 52,864 Excavator (rock) $ 54,120 $ 15,000 $ 54,120 $ 20,000 Cat $ - $ - $ - $ 4,550 Truck $ - $ - $ - $ 10,855 Tractor $ - $ 4,615 $ - $ 6,862* Materials and Equipment $ - silt control $ - $ 750 $ - $ - chainsaws. Handtools $ - $ 750 $ - $ - Woody material for structures (lwd, swd) $ - $ 13,200 $ - $ 13,200 Fence materials $ - $ 12,248 $ - $ 12,248* Permits $ - $ - $ - $ 130 Signage $ 1,200 $ - $ 1,060 $ - Administration $ - $ - $ - $ - Total Expenses $ 64,145 $ 73,199 $ 63,985 $ 130,259 Grand Total Expenses $ 137,344 $ 194,244* BALANCE $ - $ - * cost to date: there will be additional costs as fencing and planting are completed

17 06SHU01 Appendix II March 14, 2007

18 06SHU01 Appendix III March 14, 2007