GMSWORKS-3 Peace River Side Channel Restoration - BC Hydro

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Table 5 presents the restoration criteria and factors used in the site assessment, along with the physical attributes, and fish and fish habitat information. Table 5. Side Channel Restoration Criteria. Item Definition Rating / Comment Channel Extend ‐ New Area (m 2 ) Widen Area (m 2 ) Excavate ‐ Depth Depth (m) Spot Excavate ‐ Thalweg Depth (m) Spot Excavate ‐ Pool Depth (m) Inlet Excavate ‐ Depth Depth (m) Widen Area (m 2 ) Outlet Excavate ‐ Depth Depth (m) Widen Area (m 2 ) Water Supply New Inlet Area (m 2 ) Piped Inlet Habitat Complexing Cover Overhead, Instream, None Boulder Cover Area (m 2 ) Riffle Construction Area (m 2 ) ELJ/Wood Debris Structures (LWD) Area (m 2 ) Fish Access Beaver Dam Removal n.a. Cold / Clear Water Fish Benefit L, M, H Cool / Turbid Water Fish Benefit L, M, H Priority L, M, H 6.4.6 Design and Construction Mitigation Without mitigation during design and construction, development of aquatic habitat restoration projects within the floodplain of the Peace River could impact water quality, terrestrial and wildlife values. This section provides an overview of the mitigation that could be provided to ensure potential impacts do not occur, and full benefits of the restoration work is realized. Water quality impacts include the discharge of fine sediment into the water that could impact fish and fish habitat. These impacts could occur during instream construction works, surface erosion from bare surfaces exposed during construction and the discharge of drainage and dewatering flows. Mitigation from these impacts include: � Work timing and development of proper access, � Hydraulic site isolation of instream works areas including channel inlets and outlets, � Proper erosion and sediment control, and � Treatment and proper discharge of dewatering flows. Peace River Side Channel Restoration 20
Site isolation costs and contingency costs for dewatering and mitigation have been included in the site costing to reflect these requirements. Sediment Wildlife 6.5 Conceptual Level Costing In developing rough conceptual costing, a value of $10‐$30 per m 2 was developed for major restoration and development of new side channel habitat. The higher end of the range includes complexing with wood or boulders, hauling and removal of excavated materials, and sites with multiple instream works or significant access development. The lower end of the range considers simple channel excavations with local placement and grading of fills, utilization of existing complexing materials, or areas that have simple access. These values are conceptual and based on existing information and professional experience in developing habitat restoration projects, and further feasibility and technical assessment is required to develop more accurate costs estimates. In developing conceptual costing, basic unit costs were assumed and used with estimated quantities and measurements derived from site restoration plans. Site restoration costs were estimate to conceptual level assigned as AACE Class 4, +65%/‐35% accuracy 4 . Estimated costs included a contingency item for detailed design, and permitting and environmental, which is estimated at 30% of total construction costs. Habitat complexing was assumed to be applied to sites requiring the following: � Complexing Wood for ELJ and debris structures: 1 m 3 /s per 10 m 2 channel area; � Complexing Boulder Cover: Use 0.5 m 3 per 2.5 m 2 area; and � Live Staking: 2 stakes per m 2 . As described earlier, preliminary take‐off volumes and data were estimated from conceptual lay‐out drawings at each site. This data was combined with conceptual unit rate values to develop cost estimates. These values were cross‐checked with estimates of total daily equipment and labour costs, and an estimate of the time required to complete the work based on assumed productivity and volumes. Estimated unit rates are provided in Table 6, which is based on adjusted MOT Blue Book values. 4 Advancement of Cost Engineering Recommended Practice No. IOS‐090, Cost Engineering Technology, 20 May 2009. Peace River Side Channel Restoration 21
Page 1 and 2: Peace River Project Water Use Plan
Page 3 and 4: Executive Summary This study was in
Page 5 and 6: Acknowledgements The authors would
Page 7 and 8: Table of Contents Executive Summary
Page 9 and 10: 1 Scope of Work The Peace River’s
Page 11 and 12: assessment purposes. Data, analyses
Page 13 and 14: Figure 1: Pre‐Regulation Peace Ri
Page 15 and 16: Hydro via telemetry, and will be ut
Page 17 and 18: channel must be sheltered from high
Page 19 and 20: These impacts have been recognized
Page 21 and 22: while the mainstem river area was e
Page 23 and 24: Physical criteria developed in this
Page 25 and 26: a) Inlet improvements for additiona
Page 27: Studies on the Nechako River indica
Page 31 and 32: 40.5L 3.0 18.0 Ephemeral Medium 58L
Page 33 and 34: The restoration concept includes: 1
Page 35 and 36: vegetation. The most serious limita
Page 37 and 38: A series of extensively infilled ch
Page 39 and 40: 7.10 River KM 98.2R Site 98.2R cons
Page 41 and 42: compiled at a common scale to docum
Page 43 and 44: Instream Flow Needs Workshop, Walde
Page 45 and 46: Site Summary and Cost Tables Peace

GMSWORKS-3 Peace River Side Channel Restoration - BC Hydro

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