The Queen's Ditch is located three kilometers north of Comox on Vancouver Island and is
roughly 1300 hectares in size. In 1998, the watershed experienced a 1 in 200-year rain event that
flooded much of the lower watershed. The Regional District of Comox-Strathcona is responsible
for land-use planning in the watershed and initiated an investigation into the stormwater runoff
problem. This thesis is divided into two components: a planning phase to identify problems with
watershed hydrology; and a design phase to illustrate urban design that manages stormwater
runoff.
Watershed assessments were conducted at the watershed and sub-watershed scale. Watershed
assessments were descriptive and helped predict future trends in land-use change. These
assessments were not able to identify site specific problems. Sub-watershed assessment was
useful at quantifying and identifying stormwater problems. Planners should use sub-watershed
hydrological performance to guide land-use planning decisions and assess hydrological and
ecological effects of development. The planning phase provides planners with a process to
prioritize candidate areas for development, conservation, and rehabilitation.
The design phase compares urban design and stormwater performance standards of a proposed
conventional design with a sustainable design. The goal of the sustainable design was to mimic
the site's natural hydrology to help reduce off-site runoff, and to ensure adequate groundwater
recharge. Objectives of the sustainable design were to preserve natural vegetation; maintain x>£
time of concentration; reduce and disconnect impervious surfaces,, and treatment first flush
flows.
Comparisons of conventional and sustainable designs indicate that stormwater runoff and
pollution can be managed at the site level. The sustainable design provides forty-seven percent
more dwelling units and exports no stormwater. The sustainable design achieves this without an
expensive stormdrain infrastructure. Stormwater is managed at the site level using small
infiltration depressions and swales. The design works with the natural hydrological processes of
the site to generate a hydrologically sustainable design. Simulated stormwater outputs were used
to test and size infiltration ponds and to assess flooding risks. The sustainable design effectively
manages stormwater production, runoff, and pollution from storm events ranging from polluted
first flush flows to large, flood producing rainstorms.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:BVAU.2429/11812 |
| Date | 11 1900 |
| Creators | Murdoch, Scott Philip |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Relation | UBC Retrospective Theses Digitization Project [http://www.library.ubc.ca/archives/retro_theses/] |
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