Loading...
HomeMy WebLinkAboutDTS-05-155 - Ward's and Brigadoon Ponds Schedule B Class Environmental Assessment ) ~ Development & Technical Services ~ Report To: Date of Meeting: Submitted By: Prepared By: Ward(s) Involved: Date of Report: Report No.: Subject: Chair Christina Weylie and Members Development and Technical Services Committee September 12, 2005 Robert Shamess, P. Eng. Robert Shamess, P. Eng. Ward 4, South September 2, 2005 DTS-05-155 RECOMMENDATION: Ward's and Brigadoon Ponds Schedule B Class Environmental Assessment That Council endorse the Preferred Alternative as detailed in the attached Executive Summary; and That the Director of Engineering Services, Development and Technical Services Department, be authorized and directed to file the Class Environmental Assessment (EA) Project File Report for the Ward's and Brigadoon Pond Study with the Municipal Clerk for a Thirty (30) day public review commencing September 26,2005; and That the Director of Engineering Services, Development and Technical Services Department, be directed, upon completion of the public review, to prioritize the identified project within the context of the 10 year capital program. BACKGROUND: In May of 2004 the City retained the firm of CH2MHill to undertake a Schedule B Class Environmental Assessment for the Rehabilitation or Removal of the Ward's and Brigadoon Pond Dams. Although this creek/pond area had been identified within the Annual SWM Policy audit the prior year as a relatively low priority in relation to other projects the failure of the Brigadoon Pond Dam Structure in August of 2003 elevated its priority. Public Information Centres were held on June 24, 2004 to introduce the project and on May 12, 2005 to present the preferred alternative. In the interim a one day workshop was held on October 23, 2004 during which members of the public were taken on a walk of the area by members of the project team who identified issues, concerns and also positive aspects of the area, along with an afternoon session where members of MNR, GRCA, the project team and Trout Unlimited identified factors for the public to consider. It was also during the workshop that the attendees were asked to identify criteria to be used to evaluate the project alternatives and the weighting they placed on these criteria. This information was then used as part of the sensitivity analysis carried out on the project to determine the preferred solution. Part of the analysis completed by the project team included a structural review of the existing Ward's Pond Dam. This review was completed in the spring and early summer of 2004. At that time it was found that the dam embankment is founded on poor quality soil, has been constructed of poor quality material, has little structural strength, shows extensive signs of piping of water through and under the structure and has several trees which have grown into it which are showing significant signs of distress. The recommendation coming from this initial soils investigation was that this dam should be removed, then based on the recommended solution from the Environmental Assessment either construct a new dam to current standards or to not replace the embankment but leave the concrete as a "historic feature". They also recommended that in the interim the water level on the pond should be reduced to lower the hydraulic pressure on the embankment and that signage be erected to indicate the hazard represented by the dam. This work was undertaken in August and September of 2004 with an initial lowering of the water level in the pond of approximately 200mm. Community Services -Operations and DTS- Engineering staff have continually monitored the structure throughout the intervening period and have undertaken repairs to the structure as a result of some overtopping and erosion of the top of the embankment. This included construction of a sod weave on the top of the embankment to repair erosion damage, the removal of debris on the downstream channel and the placement of large rounded stone in the channel to prevent further degradation and undermining of the concrete gate structure. These repairs were sufficient only to maintain the embankment in its current state and do not preclude the recommendations of this EA. This work was completed during the same period as emergency repairs were being undertaken in the Brigadoon Pond and associated dam as a result of the August 2003 failure. Once again these works were sufficient only to stabilize the area and not preclude any recommendations from this Environmental Assessment. Present Condition of the Ward's and Brigadoon Dams Since the start of the Environmental Assessment each of the structures has been monitored on a regular basis by CS-Operations' and DTS-Engineering's Staff along with our consultants. The following is a brief summary of the present condition of each structure: Brigadoon Pond Dam - The area of the breach and upstream and downstream channels have been stabilized, work completed September 2004. A smaller pond area has started to reform as a result of the slight weir effect of the repairs and also due to some groundwater up-welling. Ward's Pond Dam - The structure continues to show signs of distress. Areas of observed piping through the embankment have been identified. During the July 16, 2005 Storm event the dam experienced significant overtopping, this has resulted in additional areas of erosion on the embankment and significant scouring of areas adjacent to the concrete structure. During recent site visits the Department of Fisheries and Oceans (DFO) requested the lowering of the water level to relieve pressure on the embankment. A recent site visit by DTS-Engineering, Ministry of Natural Resources (MNR) and DFO staff have confirmed that this should be undertaken. It was agreed that due to the significant level of potential silt and other material behind the gate structure that the lowering of the water level as a result of the direction from DFO has been completed as much as practical without causing deleterious impacts to the watercourse. This additional lowering has been completed. The Geotechnical Engineer who, as part of the EA study, completed the initial evaluation has completed a further evaluation. His recommendation is that the dam structure is under significant stress and that the water level should be lowered further. He has been asked to further review the material behind the gate structure to determine to what level the water can be lowered without negatively impacting the downstream watercourse. Council will recall that Report DTS-05-150 Emergency Repairs to the Ward's Pond Dam was brought forward at the August 22, 2005 Committee Meeting in order to address immediate safety concerns with the structure. The design of the required works is underway, however, Council should be advised that these repairs will only stabilize the structure to limit further deterioration, they are not permanent fixes and are being undertaken in such a manner as to not preclude the recommendations from the EA. REPORT: The Environmental Assessment for the Ward's and Brigadoon Pond and the reach of Strasburg Creek connecting the 2 ponds commenced in May of 2004 when the City retained CH2MHill as primary consultant to undertake the project. An overall Steering Committee comprised of City Staff, MNR and GRCA Staff and members of the consulting team was assembled in order to ensure the alternative solutions to the project would be feasible and meet with approval of the regulatory agencies. A Public Information Centre to introduce the project and solicit input was held June 24, 2004. During this session information was provided to the public with regards to the reasons for the undertaking, the regulatory process from both the Environmental Assessment and approvals aspects and some potential alternatives. In conjunction with this the consulting team began the data collection phases of the project including inventories of terrestrial and aquatic flora and fauna, geotechnical evaluation of the remaining Ward's Pond Dam and embankment, groundwater analysis and field surveys required to review the hydraulic and hydrologic aspects of the project. During the summer of 2004 an interim report on the stability of the dam was received. This report identified areas of serious concern with respect to the stability of the dam and recommended an immediate lowering of the water levels by a minimum of 150mm, with a preference for a lowering closer to 300mm. In addition the interim report recommended that the area be, as a minimum signed to advise of the danger and suggested that the area be fenced to prevent access by the public. The report also identified areas of "piping" of water through the embankment, areas of erosion and scour on the downstream side of the embankment and the channel. Work to resolve or mitigate these issues was undertaken in September of 2004. A workshop was held on October 23, 2004. Consisting of a morning guided walk of the project area by the consulting team and afternoon work session, the workshop was held to further solicit input on the project and determine the weight that the public put on various aspects of the environmental assessment analysis, including issues such as cost, and impact on the environment (both natural and cultural). The public were also provided with information on the environmental assessment process and timelines for the completion of the project. Independent of the public weightings staff from the City of Kitchener, GRCA and MNR also reviewed the criteria and identified their weightings. Each of these 4 weightings along with the equal weighting criteria required under the Environmental Assessment process were analysed to develop a preferred alternative independent of each other. In addition staff requested that the consultant team also evaluate 2 other weightings, those being "cost as no object" and "environmental aspects take priority over all others". Each of these analysis confirmed the selection of the preferred alternative being, Alternative 5 - Removal of the Ward's Pond Dam, Rehabilitation of the Natural Creek Channel through both Ward's and Brigadoon Areas and the Joining Creek Reach and the Construction of Smaller Off-Line PondslWetland features at both Ward's and Brigadoon, as identified in the executive summary. These results were presented to the public at the May 12, 2005 Public Information Centre. In addition the Consultant made a presentation to the Environment Committee on April 21, 2005 and attended a subsequent meeting of the Environment Committee May 19, 2005 to discuss the results of the PIC. At the May 19, 2005 meeting of the Environmental Committee the following recommendation was moved: "That Alternative 4 (Rehabilitate Strasburg Creek at Former Brigadoon Pond and maintain Ward's Pond), as outlined in the Brigadoon and Ward's Pond Class Environmental Assessment, prepared by CH2MHill, dated April 14, 2005, be endorsed." It should be noted that although no reasons were provided for this motion, the Environmental Committee did express concern with respect to the possible cost of the alternatives. Costs presented for the various alternatives as identified in the Executive Summary are preliminary. While the cost of construction of a new dam is estimated at $1.2 million, the estimated cost of the preferred alternative can vary depending upon the extent of works being undertaken. These would range from an estimated $600,000 minimum based on removal of the structure stop logs, excavation for an off-line pond and natural regeneration of the area up to $1 to $2 million dollars with much more extensive landscaping of the area. It should also be noted that the sensitivity analysis that reviewed the impacts on costs showed that Alternative 5 was still preferred. Alternatives To The Undertaking In addition to the technical alternatives presented in the Executive Summary, staff have been investigating possible alternatives should council choose not to endorse the preferred solution, in order to ensure Council is provided with sufficient information to make a decision. This is as a result of a recent Environmental Assessment completed by the City of Cambridge for a similar project. In this case Cambridge Council did not endorse the preferred solution, choosing to endorse another alternative, and directed staff to file the Environmental Assessment unchanged. The approval agencies objected to the Ministry of the Environment who advised Cambridge that they could not file an EA in which the recommended solution differs from the recommendation of Council. The following Sections detail the pros and cons of 4 possible scenarios. 1 - Endorse the Recommended Solution In this scenario, Council would endorse the preferred solution; staff would file the document for the 30 day public review. Upon completion of the review and assuming no Part II Orders staff would prioritize the work in the context of the capital budget and proceed to detailed design. Advantages are the City will be seen by the approval agencies as moving forward with the required work and preventing the possibility of future orders to repair the structure. Disadvantages include the possibility of a Part II Order which will require additional staff time in resolving the issues or possibility of the project being "bumped" by the Ministry of Environment to either a Schedule "C" or Individual EA status. Estimated Costs as per Executive Summary. 2 - Not Endorse Recommended Solution, however Endorse an Alternative Contained in The EA In this scenario, Council would not endorse the preferred alternative but would select an alternative which is contained within the document. This would require revisions to the EA document in order for staff to file it in the public record and with the MOE. Advantages are that the analysis has been completed and may not require additional field investigations. Disadvantages include requiring a re-write of the EA, will require the consultant to revisit the evaluation exercise and study conclusions, additional public consultation will be required. Compelling and traceable scientific rationale for the change in the recommendation would also be required. Based on the comments received from the MNR and the GRCA on the alternative that recommends that the dam be replaced, this scenario could also result in approval agencies (GRCA and MNR) requesting a Part II Order. Estimated Costs - costs to conduct additional investigations and re-write the EA are unknown but could result in an additional $50,000 in consulting costs. This is also similar to the next scenario. 3 - Not Endorse Recommended Solution and Request Staff Revisit Conclusions In this scenario, Council would not endorse the preferred alternative and would direct staff to revisit the analysis and conclusions of the EA. Advantages - there are no real advantages to this process. Disadvantages - will likely require a new consulting team to be retained to review the work of the previous team and either endorse their conclusions or provide alternate solutions, would extend timeframe a minimum of 6 months as some field investigations would need to be repeated, given the completeness of the investigations it is likely that there would be no different conclusion reached, approval and regulatory agencies may interpret this as a means of delaying required works and could potentially order the City to undertake remedial measures or undertake them and charge the City. Estimated costs - additional consulting services $60,000 to $100,000 dependent upon the extent of re-analysis, other costs unknown. Cost to undertake repairs/remediation of the dam $1.2 million, assuming dam is brought to current standards. 4 - Not Endorse the Recommendation and Direct Staff to Abandon the Project In this scenario staff would be directed to abandon the project for some period of time. There are no advantages to this scenario. Disadvantages include the potential for the City to be subject to orders and charges from the various approval/regulatory agencies, the City would be directed/advised by the Ministry of Natural Resources to undertake repairs to the structure to bring it up to current code or the MNR could proceed with the work and charge the City. Also as no work would be undertaken on the downstream channel additional bank erosion would occur. Estimated costs would be associated with the repair/remediation of the structure, $1.2 million. Staff have been advised by the MNR that they are in support of the preferred alternative as determined by the EA process. They have also advised that the City would be required to bring the dam to current standards should it be decided that the dam remain. This would, as per the recommendations of the Geotechnical Consultant, require the construction of a new dam, requiring an application for approval under the Lakes and Rivers Improvement Act. An application for rebuild will be reviewed, however if the Ministry should determine that there are valid grounds for refusal, a Notice followed by formal refusal of the application will be sent to the municipality. The construction of a new dam structure is in contradiction to the GRCA Fisheries Management plan which encourages removal of on-line ponds. Furthermore, a new dam structure would require infilling of the creek and would result in the direct loss of fish habitat. Under Section 36 of the Federal Fisheries Act, Fisheries and Oceans Canada would consider infilling of the creek a harmful alteration, disruption and destruction (HADD) of fish habitat which would likely result in unacceptable impacts to fish habitat in Strasburg Creek. Therefore, it is likely that the construction of a new dam structure for either Brigadoon Pond or Wards Pond would not obtain approval from Fisheries and Oceans Canada. Staff have also been advised by the GRCA that they are in support of the preferred alternative as per the EA. Fisheries & Oceans Canada (DFO) staff has also on many occasions expressed support for the removal of the dam structures and the rehabilitation of the two sites as a stream ecosystem. FINANCIAL IMPLICATIONS: Final costs for the works would be dependent upon the extent of off-line ponds and wetland features and landscaping proposed. If the area is left to naturally regenerate after construction of the off-line pond costs could be on the order of $600,000. Costs would increase from this point dependent on factors such as plantings etc. It is proposed that the following costs be used for budgeting on this project: Construction: Engineering and Contingencies (15%) Total $1,200,000 $180 000 $1,380,000 COMMUNICATIONS: This project has had extensive public involvement and communication. It has included 2 Public Information Centres, One Day Workshop and the use of Web- based communication through the City's Website. CONCLUSION: The preferred alternative, Alternative 5 - Removal Of The Ward's Pond Dam, Rehabilitation Of The Natural Creek Channel Through Both Ward's And Brigadoon Areas And The Joining Creek Reach And The Construction Of Smaller Off-Line PondslWetland features At Both Ward's And Brigadoon, is the result of a thorough analysis of the issues and represents the best technical solution to the problem. Robert Shamess, P. Eng. Director of Engineering Attachments: Executive Summary Correspondence from GRCA Email from MNR