Phase 2 works are expected to begin on Tuesday, October 22 or Wednesday, October 23, 2013.
Construction will begin in the Zdralek Court area.
Council awarded a contract, in the amount of $685,848, to Colmar Construction Ltd. to install Casa Loma Drainage Improvements Phase 2:
The total project cost will be $895,848 when accounting for design, testing and inspections, gas line relocations and contingencies.
The following works will be constructed in November 2013:
Drain inlets, curbs and gutters, detention storage and paving on Zdralek Cove;
Surface works, asphalt curb and gutter on Benedick Road;
Drywell installation on Alice Court;
Piped connections to existing drywells on Casa Loma Road; and,
Raising/relocating existing culvert at the Beach outfall.
The following works will be constructed in May 2014:
PHASE 2 BACKGROUND
On August 15, 2013 the District of West Kelowna hosted an open house to bring Casa Loma residents up to date on proposed Phase 2 drainage works and to outline suggested remedial works for Phase 1:
Feedback from the open house was presented at the August 27, 2013 Council meeting; and, based on favourable community input, Council directed staff to proceed with Phase 2 improvements.
District of West Kelowna hosted a public meeting with Casa Loma residents on April 30, 2013 to discuss Phase 2 of the Casa Loma Drainage Project. Following that meeting, Council directed that the Casa Loma project be deferred pending receipt of a petition of support from the majority of Casa Loma residents in the affected area by June 30, 2013.
On January 15, 2013 Council gave early budget approval to the project to allow staff to begin planning and design.
PHASE 1 BACKGROUND
From October through December 2012, Phase 1 construction was completed on several drainage mitigation measures designed to effectively control significant water flows. Phase 1 drainage measures included:
Digging ditches of various depths along the public road right of way; and,
Dressing the ditches with top soil, rip rap and turf in varying degrees and sections to control the flow of water and create a more natural esthetic.
The ditches were required due to:
The road height in relation to the lower shoulders;
The high volumes of water that could overwhelm pipes and catch basins during severe torrential rain storms in the Okanagan; and,
The high cost of installing curbs, gutters and underground infrastructure.
RATIONALE FOR DRAINAGE WORKS
After a flooding event in August 2011 and hearing concerns from area residents, Council directed that a review of Casa Loma drainage be conducted and ultimately proceeded with a two-phase approach to addressing drainage concerns in the area. Below are links to initial staff reports and a report from the District's consultant, RSB Engineering, regarding Casa Loma drainage:
Works were designed to effectively control significant water flows, which occur in the Casa Loma neighbourhood, during heavy storm events, also known as torrential rains. Severe torrential rains occur on rare occasion in the Okanagan Basin; but when they do occur, the storms deposit significant amounts of water in a short period of time, overwhelming storm drainage systems. Due to their rarity, severe torrential rains are often referred to as a "one-in-one-hundred-years event."
The last such severe torrential rain event occurred on August 10, 2011. The storm caused generalized flooding in Casa Loma and Lakeview Heights. In some neighbourhoods the runoff flooded properties and/or homes, and considerable ponding of water occurred in low lying areas. The event lead to a review of Casa Loma's existing drainage system, which had been installed many years prior to District of West Kelowna incorporation on December 6, 2007.
After careful review of the storm drainage system that existed in the Casa Loma area at the time, the District of West Kelowna determined that ditches would be required in strategic locations within the neighbourhood, in order to adequately control storm water in the event of torrential rains.
The sizes of the ditches to be constructed would be reflective of the significant volumes of water that would need to be handled during severe storms. Installing curbs, gutters and underground pipes would have been significantly more costly than the chosen plan, and could still not have entirely handled heavy water flows during severe torrential rain events.
Council chose the most cost-effective method due to the District of West Kelowna's need to remain fiscally accountable to all taxpayers in the municipality, maintain a balanced budget and strategically prioritize a high number of infrastructure needs throughout its jurisdiction.
Once the existing drainage system was assessed and the appropriate mitigation measures were identified, the District of West Kelowna held public input sessions and consulted with residents and property owners through a series of community meetings and correspondence before proceeding through to the identified stages of construction.
If you have questions or would like further information, please contact the District of West Kelowna's Engineering Department at: