Penticton Creek and Ellis Creek Restoration Committee Meeting to be held at City of Penticton, Room A 171 Main Street, Penticton, B.C.

Transcription

1 Agenda Penticton Creek and Ellis Creek Restoration Committee Meeting to be held at, Room A 171 Main Street, Penticton, B.C. Tuesday, March 12, 2019 at 9:00 a.m. 1. Call Regular Committee Meeting to Order 2. Adoption of Agenda 3. Adoption of Minutes 3.1 Minutes of the December 19, 2018 Penticton Creek and Ellis Creek Restoration Committee Meeting 4. Business Arising from Prior Meetings 4.1 Penticton Creek funding strategy Ian Chapman 5. New Business 5.1 Penticton Creek Reach 12 A Draft Predesign Jody Good, Mould Engineering 6. Council Outcome 6.1 February 19, 2019 Council Outcome 7. Next Meeting 8. Adjournment

2 Item 3.1 Minutes Penticton Creek and Ellis Creek Restoration Committee Meeting Held at Committee Room A 171 Main Street, Penticton, B.C. Wednesday, December 19, 2018 at 9:00 a.m. Present: Paul Askey, Freshwater Fisheries Society of BC Bryn White, South Okanagan Similkameen Conservation Program Representative Bruce McFarlane, Regional Water Engineer, Ministry of Forests, Lands and Natural Resource Operations Representative Doug Maxwell, Member at Large Bill Wickett, Penticton Fly Fishers Association Zoe Eyjolfson, Okanagan Nation Alliance Jim Arner, Ministry of Forests, Lands and Natural Resource Operations Fish & Wildlife Representative Kim Blagborne, Penticton Industrial Development Association Staff: Guest Staff: Guests: Ian Chapman, City Engineer Jo Benson, Corporate Secretary, Committee Clerk Anthony Haddad, Director Development Services Laurie Darcus, Director Corporate Services Shawn Kilpatrick and Joe Kennedy, Stantec Consulting 1 member at large, Penticton Indian Band David Cassidy, Valley Environmental 4 members at large, Penticton Industrial District Association Meghan Fisher, 4 Seasons Heritage Consulting 1. Call to Order The Penticton Creek and Ellis Creek Restoration Committee was called to order by the Chair at 9:02 a.m. 2. Adoption of Agenda It was MOVED and SECONDED THAT the Penticton Creek and Ellis Creek Restoration Committee adopt the agenda for the meeting held on December 19, CARRIED UNANIMOUSLY

3 3. Adoption of Minutes It was MOVED and SECONDED THAT the Penticton Creek and Ellis Creek Restoration Committee adopt the minutes of the November 21, 2018 meeting as circulated. CARRIED UNANIMOUSLY 4. Business Arising from Prior Meetings 4.1 Draft Penticton Creek funding strategy elements 5. New Business The City Engineer shared with the committee the elements of draft document to enable donations to fund future creek projects. The committee has been asked to review the document to provide input, ideas, suggestions on how to get the word out and brainstorm methods to solicit donors. A few suggestions from the committee were: Include the names of significant donors in the brochure rather than just on sculptures and plaques. Focus on the uniqueness of the project Install a thermometer type indicator of the fundraising goal and show fundraising progress. Target individual project amounts rather than the whole $30M. Consider hiring the services of a professional fundraising person to assist in setting up the program. Apply funds raised from any land sales along Ellis Creek towards the restoration costs. Bring forward your comments to the next meeting. (Draft report attached) 5.1 Update Industrial lands adjacent to Penticton Creek The Director of Development Services spoke to the committee about development considerations the City is working on with respect to Okanagan Avenue properties adjacent to Penticton Creek. An outline of the Okanagan Avenue Lands and the historical use agreement with landowners in the area to occupy municipal land was addressed. Temporary Use Permits (TUP) approved by Council in 2016 allow existing industrial uses to continue on the lands for a period of 3 years. TUP is for specific uses of the property between the 11meter buffer and the north property boundary. Extension for additional three years is subject to Council approval and will need to align with Licence to Use. A qualified Environmental Professional has completed an assessment of the Ellis Creek environment, and has recommended an 11meter buffer zone (a reduction from standard, to accommodate property owners) / setback from the High Water Mark of Ellis Creek. A variety of options to retain use of City lands is being considered for the future. Landowners representing the Okanagan Avenue businesses were in attendance and spoke to the historical use of these lands. They outlined the economic impact that the businesses have to the community and the potential negative impact of moving all Minutes of the December 19, 2018 Penticton Creek and Ellis Creek Restoration Committee Meeting Page 2 of 4

4 equipment/storage off of the city land. They also recognized the importance of the Ellis Creek lands and will be getting the landowner group together in January to discuss the licence agreements and Temporary Use Permits. The Director of Development Services stated that the Cantex Lands are subject to future application and review. Restoration and revegetation of the buffer areas is a concern and there will need to be some kind of clear delineation, physical barriers and landscape buffers to protect the sensitive areas. The City to commence soil sampling and environmental testing to determine the existence of or extend of soil contamination, if any. The City will then determine if it is in the community s interest to pursue a longer term solution of zoning amendments, subdivision and or site remediation, if required. They continue to work with land owners to come up with a solution that is in best interest to all involved. What is the future of the creek remains the biggest unknown? Guests left meeting at 9:49 a.m. 5.2 Follow up - Ellis Creek Master Plan Item 2.5 design floods and fish flows Shawn Kilpatrick from Stantec reviewed the Ellis Creek Plan Q/A log with the committee from the November 21, 2018 meeting. Recommended design flows discussed. 5.3 Follow up - Ellis Creek Master Plan Item 2.7 fisheries habitat assessment work and methodology Joe Kennedy from Stantec reviewed the fish habitat Q/A from the November 19, 2018 meeting and presented a summary of findings. Note: Refer to link sent to committee for full PowerPoint presentation of 5.2 & 5.3 Q/A log. 5.4 Culture and Heritage Inventory Mapping CHIM findings Archeological observations and types of cultural heritage values identified through the project were shared with committee by Meghan Fisher, Archeologist from 4 Seasons Heritage Consulting. Cultural Heritage Inventory Mapping of Ellis Creek (CHIM), avoidance and Archeological Impact Assessment (AIA) discussed and the importance of mapped history and arch sites and heritage values articulated. The Archeologist has requested the CHIM be integrated in the Ellis Creek Master Plan and spoke about implications of the Heritage Conservation Act. Laurie Darcus and Anthony Haddad left the meeting at 11:00 a.m. Minutes of the December 19, 2018 Penticton Creek and Ellis Creek Restoration Committee Meeting Page 3 of 4

5 6. Council Outcome Council received the minutes of the November 21, 2018 at their meeting held on December 18, Next Meeting The next meeting is scheduled for January 23 at 9:00 a.m. 8. Adjournment It was MOVED and SECONDED THAT the Committee adjourn the meeting held on Wednesday November 21, 2018 at 11:20 a.m. CARRIED UNANIMOUSLY Certified Correct: Jo Benson Committee Clerk Minutes of the December 19, 2018 Penticton Creek and Ellis Creek Restoration Committee Meeting Page 4 of 4

6 Item Fund Raising for Penticton Creek Where The Funds Go City would put the money into an account. The account would have to be a statutory reserve if it was going to accrue interest. Establishing a statutory reserve requires greater work both to set up and to draw funds as this is all required through a bylaw rather than Council resolutions. Finance would prefer to not create a statutory account, given the additional work related establishing and administering. What Kind of Donations Do we Want to Accept Habitat donations Flood restoration donations Caveat on donations, City has the right to reallocate the dollars from one use to another Not wanting to accept donations for specific areas unless the amount being donated was large enough to fund the majority of the reach. Too hard to track. Donor Recognition Develop a donor recognition program items to be considered: o X Large Donation Platinum donor. Name a Reach of the Creek after the donor and place a unique plaque at the reach in a publically accessible location, ribbon cutting ceremony donor cuts the ribbon. NEED TO SET DONATION LIMIT. o Large Donation Gold donor. Create a migrating, spawning fish sculpture. Gold donors get a large fish named after them. NEED TO SET DONATION LIMIT AND FIND OUT COST TO MAKE A LARGE FISH SCULPTURE. o Medium Donation Silver donor. Create a migrating, spawning fish sculpture. Silver donors get a small fish. NEED TO SET DONATION LIMIT AND FIND OUT COST TO MAKE A SMALL FISH SCULPTURE. o Small Donation Bronze donor. Name on a plaque to be put up at near the fish sculpture. o ALL Recognize donors on an annual basis by putting out a press release and printing an advertisement in the newspaper speaking to the achievements on Penticton Creek restoration and recognize those that donated. Add donor names to a plaque that will be put up near the fish sculpture recognizing all donations for Penticton Creek. NEED TO COST THE PLAQUE AND THE FISH SCULPTURE Getting the Word Out Develop a pamphlet describing the project, the goals, successes already achieved, the cost, funding that we have been able to secure or is in place (grants, storm water utility, general revenue and donations) how to donate, where the money goes, how it will be used and how donors will be recognized. NEED TO DISCUSS DO WE WANT TO SET A FUND RASING GOAL?

7 Start by approaching key people in the community who we think may want to make or have the ability to make a significant donation. The goal would be to get one platinum donor on board. Once this was achieved we would advertise this and use it as a springboard to launch the program. Do a fund raising launch. Press conference at Penticton Creek Show Case Project to kick off the fundraising. Address by the Mayor and Penticton and Ellis Creek Restoration Committee chair. Press Release describing the fund raising campaign. Video on site showing what has and can be achieved use Jessey Chudiak. Newspaper Advertisement Notice in the Utility Bill Social Media Decisions or Answers Required Need to set donations limits for Platinum, Gold, Silver and Bronze donations Need to finalize and cost recognition methods. The above suggests a fish migration / spawning sculpture. There could be other ways to do this. Do we want to set a fund raising goal? Concern is the overall project cost is $30,000,000 this is a big number and may scare people away from donating.

8 Item 5.1 CITY OF PENTICTON PENTICTON CREEK RESTORATION REACH 12A PROJECT DESIGN BRIEF MARCH 2019

9 CITY OF PENTICTON PENTICTON CREEK RESTORATION REACH 12A PROJECT DESIGN BRIEF MARCH 2019 Prepared by Mould Engineering 567 Lawrence Avenue Kelowna, BC V1Y 6L8

10 CITY OF PENTICTON PENTICTON CREEK RESTORATION REACH 12A PROJECT DESIGN BRIEF TABLE OF CONTENTS 1 Background Penticton Creek Master Plan and Project Selection :200 Year Flood Flow Detailed Design OBJECTIVES Revitalize channel condition Maintain flood capacity Improve fish habitat RESTRICTIONS Available Land Plant Communities Archaeological LAND TENURE HYDRAULIC RIVER MODELING HYDRAULIC DESIGN FEATURES Width, Alignment & Grade Deflector Bars Flood Capacity & Freeboard DIVERSION PIPE DESIGN AQUATIC DESIGN FEATURES Rearing Habitat Fish Migration Spawning Existing vs. Proposed Characteristics PLANT COMMUNITIES ARCHAEOLOGICAL MATERIALS Deposition Potential Cost Estimate Approvals Scheduling References Mould Engineering i

11 Preface Please note that for continuity purposes, and to ensure that this design brief can be read as a complete stand-alone document, much of the same content that was presented in the 2015 Showcase Project Design Brief and 2017 Penticton Creek Lower Reach 3A Project Design Brief is presented here. In some sections the appearance of the two documents will be the same, with only those changes needed to reflect Reach 12A versus the other two projects being made. An Environmental Management Plan was prepared by Aarde Environmental Ltd. for the Reach 12A project and should be read in conjunction with this report. Mould Engineering ii

12 CITY OF PENTICTON PENTICTON CREEK RESTORATION REACH 12A PROJECT - DESIGN BRIEF 1 BACKGROUND Lower Penticton Creek is largely a concrete-lined channel, or channel that incorporates concrete drop structures, and considerable modifications are required to improve fish habitat, migration to upper reaches and the aesthetic appeal of the creek. During recent consultation regarding revitalization work in the downtown area of the City, the public identified Penticton Creek restoration as a priority (City of Penticton, 2012). Also, the deteriorating condition of the channel means that regular maintenance is becoming increasingly important. The present channel was constructed in the early 1950s, following several flood events that caused serious damage within the City. The flood of 1942 was estimated to have been approximately 48 cms (m 3 /s, instantaneous peak). A report by the Federal/Provincial Joint Board of Engineers in 1946 studied solutions to the problem and another flood in 1948 spurred action to avoid future recurrences of damaging flood events. Construction of the channel seems to have been completed in stages, but Concrete-lined channel upstream of Front Street bridge ultimately consisted of various sections of channel with concrete bottom and sides, and additional sections where the creek bottom is constructed of natural materials with concrete drop structures installed to step the channel grade. Roughly 1.3 km of the creek is lined with concrete, which represents 30% of the total length from Okanagan Lake to Penticton Dam #2. The concrete lining is the most efficient means of accommodating the original design flood flow of 51 cms. However, the concrete is now deteriorating and in spots, the native material beneath the concrete is eroding. Mould Engineering 1

13 Reach 12A Project - Design Brief Background Attempts at restoration date back to early 2000s, when the Penticton Flyfishers Society began planning improvements to the fisheries aspects of the creek. Initial projects included the installation of concrete parking curbs along the creek bottom, increasing local water depths to help fish migration, and the construction of enhancements to a fish ladder near Wade Avenue. A Restoration Committee was formed in 2015 and grant funding for a Showcase Project was secured, to demonstrate the improvements that can be made to the channelized reaches of Penticton Creek. The design offered improvements without changing the existing flood control capacity. This project, and subsequently the Lower Reach 3A project, were completed successfully, with an impressive improvement in fisheries results and many comments from the public concerning the improved appearance of the creek. While it is understood that there are many areas of the creek that require attention, funding is not unlimited. Therefore, a steady, methodical approach is needed to accomplish the work as funding becomes available. It is also understood that there may be times when the deteriorating channel condition may need to be addressed sooner rather than later. Such was the case in the Spring of 2018, when the further failure of concrete at the toes of two structures in Reach 12A (among other areas) was considered imminent, and immediate measures were needed to prevent deterioration during the next spring freshet. At this time, large river rock was placed at the toes of Structure #37 and #38, in order to provide support, as an interim measure until more permanent repairs could be made. This rock will be incorporated in the permanent repair work planned in Reach 12A. Rock placement at toe of Drop Structure #38 Mould Engineering 2

14 Reach 12A Project - Design Brief Penticton Creek Master Plan and Project Selection 2 PENTICTON CREEK MASTER PLAN AND PROJECT SELECTION A Master Plan outlining conceptual options for restoration of lower Penticton Creek was completed in December of The plan covers the creek from Okanagan Lake (Sta ) to Penticton Dam #2 (Sta ). Thirteen reaches were identified, based on their average width, slope, bank material, and number of drop structures. Restoration concepts for each reach have been discussed by the Initiative Committee (PCRI) and a concept was selected for each reach, except for Reaches 1 and 2. These two reaches require further investigation to select a preferred design. Longer reaches were divided into sub reaches, to represent projects that could be completed within a construction window. As part of the Master Plan, an assessment of the existing fisheries habitat was completed by Steve Matthews (Matthews Environmental Consulting), to identify migration barriers and population bottlenecks that could be addressed by the restoration concepts. The fisheries sub-committee established a fisheries priority list to determine the reaches of most importance. The channel infrastructure was analyzed to determine bank freeboard, lining condition and stability, bridge clearance and drop structure condition. The risks posed by each of these items was used to prioritize the sub-reaches in a flood priority list. In addition, Cultural Heritage Inventory Mapping (CHIM) was carried out by 4 Seasons Heritage Consulting and the Penticton Indian Band (PIB), to identify items of significance along the creek. A total of 55 features were identified, with recommendations to avoid or monitor the areas during construction (4 Seasons Heritage Consulting & PIB, 2016). Two of these features were archaeological sites where artifacts were identified. These sites are outside of the Reach 12A project area. In general, the options for creek restoration are limited due to the steep gradient and the numerous commercial and residential properties which line the narrow creek corridor. By using the successful Showcase project and Lower Reach 3A project design in confined reaches, the aging creek infrastructure can be replaced while improving fisheries habitat and reducing flood risk. Mould Engineering 3

15 Reach 12A Project - Design Brief Penticton Creek Master Plan and Project Selection Looking upstream at Drop Structure #38 (prior to rock placement in Spring 2018) After review and discussion of the highest priority options, including the anticipated costs and benefits, the Restoration Committee decided to proceed with Reach 12A construction in the Summer of The proposed revitalization work identified in the Master Plan for Reach 12 (both 12A and 12B) included the replacement of Drop Structure #37, #38 and #39 with a single riffle, which would need to be quite long due to the height of the structures. Creek widening was also identified at the upstream end of Reach 12A to increase the freeboard available. Mould Engineering 4

16 Reach 12A Project - Design Brief 1:200 Year Flood Flow 3 1:200 YEAR FLOOD FLOW One of the first steps in creek restoration is to determine the design flood flow. The 1-in-200-year discharge for Penticton Creek was determined through analysis of information from several different sources, including stream flow data, photographic evidence and newspaper articles pertaining to past high flow events. Penticton Creek flow data was obtained from numerous different sources: 1. Water Survey of Canada Gauging Station 08NM118 between the years 1950 & Joint Board of Engineers, Okanagan Flood Control Report 1942 flood. 3. Water Treatment Plant records between 1997 & Dean Environmental 1998 & /Mould Engineering 2017 & Photographic evidence and newspaper articles analysed pertain to: 1. Flow over the Penticton #2 Dam spillway in 1948, 1990, 2006 & Flow in the straight portion of the concrete channel near the pedestrian bridge between Front Street and Ellis Street in 2002 & Data recorded prior to 1971 does not include the large attenuating effects of the Greyback Reservoir, which acts on a considerable portion of the upper watershed. The relationship between Penticton Creek and the Greyback Reservoir can be seen in Figure 1. Once the data from all sources was validated, it was used to perform a statistical analysis (Gumbel distribution) in order to predict the magnitude of the Q 200. A total of 39 data points make up the Gumbel Distribution, which is shown in Figure 2. The data set is included in Annex 1. The maximum daily discharge for Penticton Creek was estimated to be 40 cms. Figure 1: Penticton Creek Watershed Mould Engineering 5

17 Reach 12A Project - Design Brief 1:200 Year Flood Flow To the predicted Q 200 maximum daily discharge, a 20% factor was added to account for climate change (recommended by the Association of Professional Engineers and Geoscientists of BC when data is limited) and a further 25% peaking factor was then added to estimate the maximum instantaneous discharge. The recommended Q 200 maximum instantaneous discharge is then calculated to be 60 cms, as summarized in Table 1. Figure 2: Maximum Daily Gumbel Distribution Plot with All Data Table 1: Q200 Determination Historical info./data/photo review = 40 cms Add 20% for climate change = 48 cms Add 25% for peaking factor = 60 cms Recommended Maximum Daily Q 200 = 48 cms Recommended Maximum Instantaneous Q 200 = 60 cms Therefore, the 1-in-200-year flood flow that the entire channel must be capable of passing is 60 cms. This value has been discussed by the Committee, which includes Ministry of Forests, Lands and Natural Resource Operations representatives. The proposed flood flow values have also been endorsed by the Penticton City Council, thereby enabling the design work to proceed. Mould Engineering 6

18 Reach 12A Project - Design Brief Detailed Design 4 DETAILED DESIGN The planned Reach 12A restoration project is located adjacent to Penticton Avenue. This area was chosen as the next priority for restoration for the following reasons: Addresses the deterioration of the concrete channel lining at the drop structures; Maintains flood capacity; Provides future fish spawning opportunities; and Ability to construct a reasonable length within the available budget in Design Drawing set COP-104-?? is included in Annex OBJECTIVES Revitalize channel condition After many years of service, the concrete drop structures are deteriorating, exposing the native material beneath to the scouring effects of high flows. As scour takes place, further destabilization and deterioration of the remaining concrete occurs. If the structures were to fail completely, Concrete deterioration prior to placement of rock in Spring 2018 Mould Engineering 7

19 Reach 12A Project Design Brief Detailed Design significant channel bedload would be released potentially in a short period of time which could lead to serious flooding in downstream deposition areas Maintain flood capacity One of the primary concerns behind the Reach 12A Project design is to ensure that any changes to the creek do not diminish the ability of the channel to pass flood flows. Changes must meet the standards laid out in the BC Dike Design and Construction Guideline. These standards are discussed in Section Improve fish habitat Another objective behind the Reach 12A Project design is to improve fish habitat. The present channel is relatively straight and shallow with a very low gradient between the drop structures, which is not conducive to spawning. Reach 12A offers one of only a few opportunities to increase the amount of spawning habitat available, as the channel in the area is generally not constricted by development. Taking advantage of this opportunity requires the acquisition of additional land base, however. Initially, fish habitat will be improved by providing passage at each of the riffles, but utilization is likely to be limited until the restoration of lower reaches take place, where failing drop structures have created barriers which limit the ability of migrating fish to navigate to upper reaches of the creek including Reach 12A. 4.2 RESTRICTIONS Available Land Much of the Penticton Creek channel was realigned in the 1950s to protect the City of Penticton from flooding. During the Master Plan process, air photos from 1938 were reviewed and it was discovered that the channel is slightly straighter, and therefore steeper than it was prior to the channelization. However, the construction of 39 drop Reach 12A historical creek alignment shown by green dashed line structures across the creek has reduced the grade between the structures significantly. Mould Engineering 8

20 Reach 12A Project Design Brief Detailed Design One of the ways to improve both fish habitat and channel appearance is to remove the drop structures and introduce a more natural meander flow pattern using natural (rock) materials to establish grade changes. Through the design process, it was determined that a corridor of approximately 40 m wide (16 m bankfull + 24 m floodplain) would be required to pass the flood flow and remain relatively stable. However, a corridor width of roughly only 30 m was established in the early 1950s for construction of the existing channel. There are several locations along the creek where the bottom is wider and a broader corridor is available for incorporating a floodplain, such as Reach 12A, although property acquisition to the north of the existing channel is required in order to realize the full potential of the available land base. The corridor available through the Reach 12A site (without property acquisition) is approximately 20 m wide, which is significantly less than required for natural conditions Plant Communities The CHIM report identified three significant plant communities within Reach 12. Abundant Tule was found on the northeastern side of the channel between Structure #37 and #38, Horsetail was found on the southwestern bank downstream of Structure #37 and a diverse plant community was found on the northeastern side of the channel upstream of Structure #39. It is recommended that all three plant communities either be avoided or salvaged for replanting Archaeological While the CHIM report did not identify items of historical significance within Reach 12, the bench at the base of the raised ridge northeast of the channel has been identified as having Archaeological Potential. Areas of Archaeological Potential are observed to have intact sediments, large trees indicating intactness of original landform or a potential buried original landform. These areas may have some level of previous disturbance but were observed to retain their archaeological potential (4 Seasons Heritage Consulting & PIB, 2016). The CHIM report recommended Recording, Avoiding, completing an Archaeological Impact Assessment or monitoring the landform. 4.3 LAND TENURE As shown on the accompanying map, land ownership along the existing channel through Reach 12A includes: North side Two privately owned parcels (Lot 28, Plan KAS817 & Lot 3, Plan KAP306), each extending below the top-of-bank; and Parcel owned by the (zoned P2-Parks and Recreation), which extends above the top-of-bank upstream of Structure #38. South side Two parcels owned by the (zoned P2-Parks and Recreation). Mould Engineering 9

21 Reach 12A Project Design Brief Detailed Design FIGURE 4: LEGAL PLAN of REACH 12A PROJECT AREA Zoning A - Agriculture R2 - Small Lot Residential RD1 - Duplex Housing RM1 - Bareland Strata Housing RM2 - Low Density Multiple Housing RM3 - Medium Density Multiple Housing RM4 - High Density Multiple Housing P2 - Parks and Recreation Images courtesy Mould Engineering 10

22 Reach 12A Project Design Brief Detailed Design 4.4 HYDRAULIC RIVER MODELING A computer model of Penticton Creek was created using the U.S. Army Corps. of Engineers HEC-RAS hydraulic river modeling software, to simulate the effects of proposed changes to the channel design. The HEC-RAS models can be used to predict changes in flow characteristics (water level, velocity, and discharge capacity) based on channel geometry and substrate. In order to establish a baseline data set for comparison, a model was first created using existing surveyed channel cross section information and a Manning s n (channel roughness) value of The predicted effects of high flows in the existing channel could then be modeled, including the expected freeboard to existing structures such as Penticton Avenue and properties to the north and south of the channel. A variety of changes to the design of the channel were then modeled and evaluated, until a design was found which satisfied as many of the requirements as possible. Roughness of the proposed channel will increase due to the preferred rock materials (discussed in Section 4.7), so for the purposes of modeling, the following Manning s n values were used where riffles are proposed: Table 2: HEC-RAS Manning s n-values Proposed riffles Material Type cms cms > 25 cms Large riprap & cobbles Note: Larger n value means rougher channel. The HEC-RAS model results for the existing and proposed channel designs are included in Annex 2. It should be noted the HEC-RAS program alone cannot correctly model every condition encountered. Hand calculations are completed to assist with the modeling, as necessary. 4.5 HYDRAULIC DESIGN FEATURES Following are the key features of the proposed design Width, Alignment & Grade While the overall present channel width is less than the 40 m needed to allow spawning substrate to remain stable at high flows, channel widening has not been included in the design due to the need for additional land to be acquired, and the anticipated additional costs that would be incurred to complete this level of restoration at this time. The design instead focuses on restoring the channel at each of the failing drop structures, accomplished by removing concrete at each drop structure and constructing a rock riffle. A low-flow channel that incorporates a two stage V-shape will be included in the riffle design to increase the water depth during low flows and to aid in the creation of a central torrent during high flows. Rip-rap will extend to the top of bank at each riffle. The present channel grade through Reach 12A is approximately 3%. While the proposed design retains the existing overall channel grade in order to connect the upstream and downstream ends, Mould Engineering 11

23 Reach 12A Project Design Brief Detailed Design riffles are designed with a slope of 8%. The current grades at the drop structures ranges between 19% and 37%. Four (4) riffles are included in the design to reduce the height of each drop, thereby improving fish habitat characteristics, as discussed in Section Deflector Bars To protect the southwest channel bank near Penticton Avenue from erosion, and to encourage the shift of the channel centreline to the northeast through the mobilization of deposition material in the gravel bars, rock deflector bars are proposed between Sta and (approx.). These deflector bars will create back eddies and lead to material deposition between the bars during low flows and will be overtopped during high flows, so they do not to reduce the total channel discharge capacity. Mobilization of gravel bar material will occur naturally over time Flood Capacity & Freeboard The proposed creek channel will be capable of passing a 60 cms instantaneous flood event with a bank elevation that meets the BC Dike Design and Construction Guideline standard of the higher of 1 in 200-year instantaneous flow plus 0.3 m freeboard, or the 1 in 200-year maximum daily flow plus 0.6 m freeboard. (BC Ministry of Water, Land and Air Protection, 2003). Existing high-water levels will remain unchanged or will be slightly lower under the present design, as each riffle is designed to be slightly lower than drop structure that it replaces. It should be noted that there are currently three areas where a high creek water level has the potential to increase the water table in the area. At two of these locations, private property infrastructure could be adversely impacted. As noted earlier, addressing this channel deficiency requires the acquisition of additional land in order to widen the channel. This should be considered as future work within this reach. 4.6 DIVERSION PIPE DESIGN Since the Reach 12A project will involve reconstruction of the entire channel bed at each of the drop structures, it will be necessary to divert the creek flow into a bypass pipe and relocate all fish prior to construction. The diversion pipe used must be capable of passing a potential 1:10 year summer event, calculated as approximately 1 cms using the Gumbel methodology discussed in Section 3. The pipe chosen and purchased by the for the 2018 Lower Reach 3A project is 750 mm in diameter, which was installed along with a 1.5-metre-high diversion dam. This configuration was able to pass all flows during construction. The intent behind the City s purchase of the pipe in 2018 was to reduce the cost of future diversion needs. As such, the 750 mm pipe should be made available to the contractor undertaking the Reach 12A project. It should be noted that an additional length of diversion pipe may need to be purchased to allow the pipe to span the entire work area, should the entire extent of work outlined in this brief be undertaken. Alternatively, the diversion pipe could be moved during the project. Mould Engineering 12

24 Reach 12A Project Design Brief Detailed Design The exact location and length of the diversion pipe and details of the diversion and containment dams will be Flow (cms) 4.7 AQUATIC DESIGN FEATURES The Reach 12A Project has been designed to maximize habitat values for kokanee and rainbow trout within the constraints of channel corridor width and identified flood protection requirements. The design incorporates several features which have the potential to: develop rearing habitat for juvenile rainbow trout; improve migration for both fish species; and retain gravel to facilitate spawning when run-off flow rates are sufficiently low Rearing Habitat The stream flows of most interest from a fish habitat perspective are the lower flows. As Penticton Creek is relied upon for irrigation and domestic water supply, the flow rates are typically governed by releases from Greyback Reservoir and the s water treatment plant. The exception, as shown on the hydrograph below, is during spring freshet or storm events. The low daily flows recorded by the water treatment plant between the years 1999 and 2014 range between 0.05 and 0.30 cms. The average during this period is approximately 0.20 cms. It is our understanding that the tries to maintain a minimum low flow of 0.23 cms. As shown in the example 2013 hydrograph (Figure 6), during much of the year flows were less than 0.50 cms. FIGURE 6: 2013 PENTICTION CREEK FLOW 0 1-Jan Jan-13 3-Mar-13 2-Apr-13 3-May-13 2-Jun-13 3-Jul-13 2-Aug-13 2-Sep-13 2-Oct-13 2-Nov-13 2-Dec-13 2-Jan-14 Date A feature that will significantly contribute to the rearing habitat value is the installation of riffles constructed of large river rock. The riffles facilitate increased invertebrate production and offer areas for small fish to seek refuge. In order to maximize the habitat benefits during periods of low Mould Engineering 13

25 Reach 12A Project Design Brief Detailed Design flow, as noted earlier the riffles will have a V-shape incorporated into the design, which acts to increase the depth of water, providing higher quality rearing habitat. No rock clusters or woody debris structures are proposed in Reach 12A, as the available pool habitat will be limited. Rock clusters and woody debris structures could be incorporated into future work in this reach Fish Migration Fish migration will be improved through the replacement of concrete drop structures with riffles constructed of natural materials. This will increase water depths and create local back eddies which will reduce water velocities, provide resting areas, and offer multiple migration corridors. Riprap on the sides of the channel will potentially contribute to improved adult migration (kokanee and rainbow trout), as well as juvenile rainbow trout migration and rearing values along the stream margins Spawning Since the Reach 12A project is focussed on the replacement of deteriorating drop structures with large river rock (much larger than required for spawning), the ability to increase spawning habitat is limited at this time. The present channel is too narrow to retain spawning gravel at high flows. Channel widening, incorporating spawning gravel, could be included with future work in this reach. TABLE 2: PREFERRED WATER DEPTH, VELOCITY AND SUBSTRATE SIZE FOR SPAWNING Species Minimum Depth (m) Velocity (m/s) Maximum Substrate Size (mm) Kokanee Rainbow Trout (, 2017) Existing vs. Proposed Characteristics Before construction on the Showcase project began in 2015, the existing channel was evaluated by Matthews Consulting to determine its Habitat Quality Rating. The existing rating for Reach 12A is Low+ (Mould Engineering, 2015). As habitat improvements in Reach 12A will be limited, and utilization will be restricted by downstream barriers to migration, the Habitat Quality Rating is expected to be only marginally better upon the completion of construction. 4.8 PLANT COMMUNITIES Of the three significant plant communities identified, one is upstream of the proposed rock riffle that will replace Structure #39 and will not be impacted by construction activities, while the design seeks to leave the Tule plant community intact in it s present location, and the impact of the design on the Horsetail plant community Mould Engineering 14

26 Reach 12A Project Design Brief Detailed Design 4.9 ARCHAEOLOGICAL As recommended in the project proposal, it is recommended that an Archaeological Impact Assessment (AIA) be commissioned. Prior to commissioning, the will be consulted to approve the work and expenditure MATERIALS After discussion with the Restoration Committee, it was decided that large river cobble will be used to construct the riffles on the channel bottom, and riprap (large and small) will be used to protect the channel banks. The size of each material will range between 400 mm and 800 mm in diameter, which, based on the tractive forces, will ensure it remains stable during high flow events. These natural materials are superior to the use of concrete, for the following reasons: 1. They are less erodible and therefore will last longer; 2. They promote a more natural channel appearance; 3. They are less expensive; 4. They are more environmentally-friendly, and is the only material approved for use in areas where natural stream conditions exist. Voids between the large river cobble on the bottom of the channel will be filled with smaller native material and densified using water in order to ensure that water flows over the rocks rather than through them. Large riprap bank protection will extend up both sides of the channel to an elevation that is 300 mm above the 60 cms maximum instantaneous water level. Small riprap will then be placed on top of the large riprap and will extend 600 mm above the 48 cms maximum daily water surface level. The result will be a mm thick layer of small riprap which will help fill the voids at the top of the large riprap and allow the voids between the small rocks to be filled with topsoil in order to support low-growing vegetation. Voids along the riprapped bank will be filled with native material in order to support natural grasses above the 13 cms water level. Mould Engineering 15

27 Lower Reach 12A Project Design Brief Deposition Potential 5 DEPOSITION POTENTIAL The channelized section of Penticton Creek is located in an alluvial fan created by deposition of sedimentary materials. The sediments are the result of stream erosion in the upland mountainous areas. Erosion usually occurs during peak spring flows and eroded material is then deposited when the stream reaches the lower gradient channel in the alluvial fan. Sedimentation in natural channels reduces capacity and eventually results in overtopping; however, as outlined below, Penticton Creek has far from natural channel conditions. Regardless, concern has been expressed whether the modified channel as detailed in this report could become sedimented in and result in a flood event in the City. Several factors unique to Penticton Creek come into play that alter the natural processes. Firstly, the source of deposition material from the upper watershed is very limited due to Penticton #2 Dam (shown right). The dam is located just upstream from the channelized section Penticton #2 Dam Spillway and any eroded material coming down the creek settles out in the reservoir created by the dam. The reservoir is relatively large, with storage capacity of 71,500 m 3 and a surface area of approximately 2 hectares. Secondly, downstream from the dam is 4.5 km of mostly man-made channel with 39 drop structures. The channel below the dam is protected from erosion by either a concrete lining, by cobbles, or by flat grades created by drop structures. The channel banks are generally only a couple of metres high, so potential landslide areas that could create a large sediment source are limited. There is one high bank north of the creek and just downstream of the old golf course (shown in the next photo), however it is comprised of bedrock. Mould Engineering 16

28 Lower Reach 12A Project Design Brief Deposition Potential The drop structures reduce sections of the channel grade to something equal to, or less than, the original natural grade. Erosion of unlined sections of channel is minimized by the drop structures. The drop structures were generally constructed with upstream pools. The pools tend to settle out most of the bedload carried by the creek. Only smaller-sized particles get rolled through the ponds. #35 #37 #38 #39 Bedrock outcrop Upper Drop Structures (image ) Note that the drop structures were re-labelled as part of the Master Plan process, beginning with Structure #1 closest to Okanagan Lake. Therefore, the numbering shown differ from the Showcase Design Brief, completed in Deposition upstream of Drop Structure #38 Mould Engineering 17

29 Lower Reach 12A Project Design Brief Deposition Potential Only Structures #38 and #39 show evidence of significant deposition after 66 years of operation. It was noted that the section upstream of Structure #39 has no concrete lining and is narrow, so high creek velocities would tend to move material from this section. Included in the 66 years, are 1:20 year (1952), 1:13 year (1955), and 1:10 year (2016 & 2017) events. Structures #36 and #37 have large upstream pond areas with very little obvious deposition. Thirdly, since construction of the Greyback Dam, the additional storage volume reduces downstream peak flows and consequently reduces erosion potential. The proposed design for Reach 12A will lead to the mobilization of some of the previously deposited material trapped behind the three drop structures, as a result of lowering the height of structures in order to provide additional freeboard. This mobilized material will be trapped by the pool upstream of Structure #35. It is recommended that the monitor the condition of this pool over time to determine whether material removal is necessary. Relatively easy access to this pool is presently available. Mould Engineering 18

30 Lower Reach 12A Project Design Brief Cost Estimate 6 COST ESTIMATE The estimated cost for the restoration of Reach 12A is $??????? and is included in Annex 3. The estimate is based on the following: 1. Labour rates and costs of materials assuming completion in The entire project being completed at a time of low creek flows. It may be necessary to update the cost estimate upon issuance of regulatory approvals. Mould Engineering 19

31 Reach 12A Project Design Brief Approvals 7 APPROVALS Numerous approvals and notifications are required prior to the commencement of construction. These include Mould Engineering 20

32 Reach 12A Project Design Brief Scheduling 8 SCHEDULING As there are instream works involved, most of the project must be constructed within the instream work window of July 22 to August 24. For the contractor to have enough time to organize, a contract should be awarded by. The following minimum time allowance schedule is suggested: Table 3: Important Schedule Dates Preliminary Funding Approval Prepare Environmental Protection Plan Applications for Regulatory Approvals Complete Detailed Design Drawings Contract Documents & Construction Drawing Preparation Update Cost Estimate Tender Advertising Pre-Tender Site Meeting Obtain Final Approvals Tender Closing Final Funding Approval & Tender Award Mobilization of Equipment Construction Out of stream Construction - Instream July August 2020 This report was prepared by Mould Engineering: Jody Good, AScT Author Stuart Mould, P.Eng Reviewer Mould Engineering 21

33 Reach 12A Project Design Brief References 9 REFERENCES 4 Seasons Heritage Consulting & Penticton Indian Band (PIB) (2016). Letter Report: Results of the Penticton Indian Band and 4 Seasons Heritage Consulting, Cultural Heritage Inventory Mapping (CHIM) of Penticton Creek, July 27 29, Aarde Environmental Ltd. (2017) Effectiveness Monitoring for Showcase Project. Year , Penticton, BC. British Columbia Ministry of Water, Land and Air Protection, Flood Hazard Management Section, Environmental Protection Division (2003). Dike design and construction guide: Best Management Practices for British Columbia. Retrieved from: pdf (2012). Downtown Revitalization 200 Block Nearly Complete. Retrieved from: Mould Engineering (2015)., Showcase Project Design Brief. Mould Engineering (2017)., Lower Reach 3A Project Design Brief. (2017). Master Plan. Mould Engineering 22

34 ANNEX 1 Gumbel Distribution Data Set

35 Penticton Creek - Gumbel Distribution Data Set March, 2019 Rank Year Penticton Creek Flow (ML/d) Maximum Daily Discharge, Q (m3/sec) Return Period or interval (Tr) = (n+1)/m Source Joint Board of Engineers Report WSC Gauging Station WSC Gauging Station Site observations/photos Site observations/photos Photographic evidence (May 23) Photographic evidence WSC Gauging Station Old Treatment Plant Photographic evidence Photographic evidence WSC Gauging Station New treatment plant data WSC Gauging Station Photographic evidence WSC Gauging Station WSC Gauging Station New treatment plant data New treatment plant data New treatment plant data Dean Environmental New treatment plant data New treatment plant data New treatment plant data New treatment plant data WSC Gauging Station New treatment plant data Dean Environmental New treatment plant data New treatment plant data WSC Gauging Station New treatment plant data New treatment plant data New treatment plant data WSC Gauging Station New treatment plant data New treatment plant data New treatment plant data New treatment plant data

36 ANNEX 2 HEC-RAS Analysis HEC-RAS analysis in progress

37 ANNEX 3 Cost Estimate Cost estimate preparation in progress

38 ANNEX 4 Drawing Set COP-104 Design drawing provided as a separate, stand-alone attachment at this time

39

40 Item 6.1 Regular Council Meeting held at Council Chambers 171 Main Street, Penticton, B.C. Tuesday, February 19, 2019 at 1:00 p.m. Resolutions Penticton and Ellis Creek Restoration Committee Meeting Minutes The Penticton and Ellis Creek Restoration Committee Meeting Minutes were approved as part of the February 19, 2019 Consent Agenda, resolution 51/2019. Minutes of February 19, 2019 Regular Council