TITLE:
Modeling Urban Hydrology: A Comparison of New Urbanist and Traditional Neighborhood Design Surface Runoff
AUTHORS:
Christopher Andrew Day, Keith Allen Bremer
KEYWORDS:
Urban Hydrology; New Urbanism; Runoff Modeling; Land Use
JOURNAL NAME:
International Journal of Geosciences,
Vol.4 No.5,
July
17,
2013
ABSTRACT:
Urban development generally leads to an increase in
impervious cover resulting in a greater volume of surface runoff following
storm activity. However, the type of urban development in place
strongly controls the degree of impervious cover generated. Traditional
neighborhood designs focus on a medium-to-low urban density spread over larger
areas, while new urbanist neighborhood designs incorporate more diversity by
increasing urban density across smaller areas. The purpose of this study is to
model and compare the potential surface runoff for two urban neighborhoods in
Austin, Texas-Circle C Ranch, a traditional neighborhood design, and Mueller, a
new urbanist development for a 10-year 24-hour storm scenario. Potential
surface runoff was calculated by layering various geospatial datasets
representing the physical characteristics of both study sites within the
Watershed Modeling System (WMS) to configure the HEC-HMS runoff model. Results
initially imply that the higher density new urbanist neighborhood significantly
increases total and peak storm runoff compared to the traditional neighborhood.
However, a greater number of residential units are available at Mueller over
the same area as Circle C Ranch. When taking this into account the increased
potential surface runoff is negated at the new urbanist site. Although new
urbanist neighborhoods will usually contain more residential units than
traditional developments when compared at the same scale, the higher urban
density associated with these neighborhoods demand the development of more
effective stormwater retention systems to cope with a potential increase in
surface runoff.