WATER RESOURCES
VALDOR
EST. 1992
ENGINEERING INC.
Yonge and Elgin Mills Flood Mitigation Municipal Class EA, Town of Richmond Hill, Ontario
Client: Town of Richmond Hill
The Town of Richmond Hill retained the services of Valdor Engineering to complete a study following the Municipal Class Environmental Assessment (EA) process (Schedule B) to investigate and evaluate the options for flood mitigation to improve the level of protection within a flood vulnerable area located in the vicinity of the Yonge Street corridor between Elgin Mills Road and Levendale Road. The watercourse that traverses the flood vulnerable area is known as German Mills Creek and it tributary to the Don River. The primarily industrial area lies within the Regional floodplain and, as such, the future development of this area is severely restricted. As per the Preliminary Flood Remediation Study,
Yonge Street Corridor (Adjacent German Mills Creek) Between Elgin Mills Road and Levendale Road (Valdor, October 2013), a long list of potential flood mitigation options were reviewed and a short list of options that achieve a substantial reduction in the extent of the Regional floodplain were identified for further review and consideration. The purpose of this study was to further evaluate the short list of feasible flood remediation alternatives and, following the Class EA process, identify a preferred alternative for improvements to the existing municipal and/or private conveyance system to remediate Regional flooding within this flood vulnerable area. Due to the wide, shallow urbanized floodplain, previous efforts to model the flooding using HEC-RAS were unsuccessful and it was determined that a 2-D hydraulic model was required to accurately characterize the extent of flooding. All hydraulic analyses were completed using Mike Flood (coupled M11 and M21) in conjunction with ArcGIS. The preferred alternative was identified in consultation with the Town, TRCA, other agencies and stakeholders through public consultation. The study outlined an implementation and phasing strategy for the preferred alternative and included the preparation of preliminary engineering design drawings and detailed construction cost estimates.
Project Profile - Water Resources
VALDOR ENGINEERING INC.
Consulting Engineers & Project Managers
VALDOR
Massey Creek Flood Reduction Study, Feasibility and Analysis, EA and Detailed Design, Cobourg, Ontario
Client: Town of Cobourg and GRCA
The Town of Cobourg under the direction of the Ganaraska Region Conservation Authority (GRCA), retained Valdor Engineering to complete an engineering analysis to determine the feasibility and cost viability of extending an existing flood diversion channel to King Road as a flood reduction measure in order to maximize the extent of developable land within the Lucas Point Industrial Park. Deliverables included an EA report, public meetings, cost-benefit analysis, detailed engineering drawings for construction and detailed construction cost estimate. The project was completed following the Municipal Class EA Process (Schedule ‘B’). The preferred option included a diversion channel, a flow control structure and a cross-over structure. The proposed diversion channel starts
immediately downstream of King Street and connects with the existing diversion channel upstream of Normar Road. The proposed diversion channel is approximately 900 m long including a 150 m long collector ditch. The diversion channel has a typical bottom width of 18 m, a side slopes of 3:1 (H:V), and a top width of approximately 27 m. The bottom of the diversion channel ties into the existing creek at the upstream end at King Street and to the existing diversion channel at the downstream end near Normar Road. The diversion channel is designed to convey and contain flows from events greater than approximately the 2-yr up to the Regional event thereby reducing the existing floodplain within the Lucas Point Business and Industrial Park. Flow less than or equal to approximately the 2-yr storm flow will be conveyed through Massey creek. A crossover structure was designed within the existing diversion channel downstream to convey flow from the existing creek across the diversion channel. A portion of the existing creek is to be realigned in the vicinity of the proposed crossover structure. The proposed flow target for Massey Creek in the vicinity of the diversion channel was confirmed through geomorphic assessment and optimized as required.
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Project Profile - Water Resources
VALDOR ENGINEERING INC.
Consulting Engineers & Project Managers
VALDOR
Flood Remediation Feasibility Study, Town of Richmond Hill, Ontario
Client: Town of Richmond Hill
The Town of Richmond Hill secured the services of Valdor Engineering Inc. to complete a flood remediation feasibility study for an existing flood vulnerable area developed within the floodplain in the vicinity of Elgin Mills Road and Yonge Street. Tasks associated with the project include review and update of the existing hydrology model, detailed topographic and stormwater conveyance system survey, review and evaluation of available 2D and 1D/2D coupled hydraulic/hydrodynamic modelling programs, preparation of Digital Terrain model (incorporating buildings, roads, floodwalls and all other important topographic features) as a Mike Flood bathymetry, establishment of a 1D/2D
coupled hydraulic/hydrodynamic model using Mike Model manager to prepare flood depth map, velocity map, flood flow direction map, flood video animation and depth-velocity product map including the Regional floodline map. All open channels, closed underground pipes, buildings, roadways including surface features/structures (either existing or proposed as part of a remediation solution) such as flood walls, retaining walls, culverts, bridges, raising grades, flood bypass channel/closed conduit were modelled by the Mike 1D/2D coupled system. The coupled model was used to identify and assess the performance of various flood mitigation strategies (about 13 mitigation options were investigated). In addition, cost estimates for the preferred options and study report were prepared. An outcome of the available model review and evaluation done in this project was that 1D/2D hydraulic/Hydrodynamic modelling by Mike model manager (Zero/Flood/Urban) appeared to be more effective and comprehensive to model complex 1D and 2D urban features including buildings, roadways, underground conduits, major and minor systems including wide range of hydraulic structures and open channels, ponds, lakes and estuaries.
Project Profile - Water Resources
VALDOR ENGINEERING INC.
Consulting Engineers & Project Managers
VALDOR
Cooksville Creek Flood Mitigation Analysis, Detailed Design and Construction Services, Mississauga, Ontario
Client: City of Mississauga
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The City of Mississauga secured the services of Valdor Engineering Inc. to complete a flood mitigation analysis and detailed design for an existing flood vulnerable area that has experienced serious flooding due to large rain storms that occurred in 2009 and in 2013. The site currently floods during the 2-yr to 5-yr design storm. The subject reach of Cooksville Creek has flooded to the point where surface water has reached the townhouses at 3400 Rhonda Valley adjacent the creek. Most recently, on 08 July 2013, a large rainfall event resulted in surface flooding of the creek, pedestrian walkway adjacent 3400 Rhonda Valley, some of the townhouse units at 3400 Rhonda Valley and the roadway
near the low point of Rhonda Valley. It was noted through discussions with local residents and a review of correspondence related to previous flooding occurrences that much of the property damage has also resulted from basement flooding via the floor drains which connect to the sanitary sewer. Tasks associated with the project included review and update of the existing hydrology model, detailed topographic and stormwater conveyance system survey, detailed design of local drainage improvements (high capacity inlet CB’s and enlarged storm sewer) and creek capacity improvements (creek widening and stabilization), agency approvals (CVC, Region of Peel, DFO), tender preparation and construction services. A number of additional background investigations were completed as part of the flood control study including geotechnical studies and analyses, a terrestrial resource assessment and a geomorphological study. The proposed flood mitigation design will provide overall protection for events up to and including the 50-year storm (including protection from creek flooding and localized drainage).
Project Profile - Water Resources
VALDOR ENGINEERING INC.
Consulting Engineers & Project Managers
VALDOR
Lower Humber River 2D Hydraulic Study and Floodplain Mapping, Toronto
Client: TRCA and City of Toronto
Valdor Engineering Inc. was retained by the TRCA and the City of Toronto to undertake a two-dimensional (2D) flood study using the available LiDAR topographic survey, field survey and land use details to re-evaluate existing 1D flood line limits and elevations and to assess the flood vulnerability of the Humber Waste Water Treatment Plant from both a regulatory and operational perspective. The 1D open channel/closed conduit flow network was modelled using the Mike 11 Hydrodynamic Modelling system. The 2D overland flow area was modelled using the Mike 21 Hydrodynamic Modelling system. The 1D and 2D models were then coupled using the Mike model manager. The Mike model manager (Zero/Flood/Urban etc.) is a state-of-the-Art sophisticated hydrodynamic modelling system that allows appropriate and accurate modelling of complex
topographic and urban features such as buildings, roadways, surface and underground conduits, wide range of hydraulic structures including open channels, ponds, lakes and estuaries. The primary outputs of the 1D/2D couple model were flood depth, velocity, flood flow direction, which were used to prepare flood depth maps, water surface elevation maps, flood flow direction maps and video-animations, velocity maps and flood line maps. The 1D/2D coupled hydraulic model was very effective to identify the extent and depth of spill that occurs in the vicinity of a group of road and rail crossings that could not be characterized accurately with the previous model due to inherent 1D modelling limitations. A limited
number of observed data was used for verification of the flood extent and depth that showed good agreement with the simulated results.
Project Profile - Water Resources
VALDOR ENGINEERING INC.
Consulting Engineers & Project Managers
VALDOR
Jane Street and Wilson Avenue 2D Hydraulic Model Update and Floodplain Mapping, Toronto, Ontario
Client: Toronto and Region Conservation Authority
Valdor Engineering Inc. was retained by the TRCA to undertake a two-dimensional (2D) flood study using the available LiDAR topographic survey, field survey and land use details to develop a coupled Mike Flood model to define the extent of flooding for the 2-yr through 350-yr storm events and Hurricane Hazel, and prepare new engineered floodplain mapping for the study area. The study area along Black Creek extended from Gravenhurst Avenue to downstream of Lawrence Avenue. The main objectives of the study included an assessment of the extent of flooding for future use in the regulation area and to identify the causes of flooding to further inform other technical studies being undertaken in the study area. As a result of limitations of the HEC-RAS modelling used in the previous floodplain mapping, spills, split flow conditions, and the extent of
flooding throughout the study area were never well accounted for or assessed. A better understanding was required regarding flooding effects on adjacent land use decisions, the development of appropriate flood proofing standards, as well as the assessment of flood risk conditions. Due to the complex hydraulics including multiple spill locations and flow directions, and flow around buildings, the capabilities of the HEC-
RAS model were not adequate to accurately account for these conditions and a sophisticated two-dimensional (2D) model was required. The
existing reach of Black Creek is concrete lined and not sufficiently sized to convey the Regional flow which results in widespread
flooding through the flat developed area adjacent the watercourse. Project tasks included the preparation of a coupled 1D / 2D Mike Flood model for the study area including model
validation, comparison of results with the existing HEC-RAS model, characterization and risk assessment of the floodplain, identification of hydraulic constraints, preparation of a technical report, preparation of digital engineered floodplain mapping and flood scenario video animations, and a one-day training session for the client.
Project Profile - Water Resources
VALDOR ENGINEERING INC.
Consulting Engineers & Project Managers
VALDOR