Technical Results
Post-construction Impacts on Water Quantity
Construction | Post-construction
After all of the impervious surfaces were installed and construction
ceased in the Traditional subdivision, the volume, depth and peak
discharge of stormwater leaving the site increased significantly
(Figure 1). In contrast, after construction finished in the LID subdivision,
stormwater runoff volume significantly decreased from pre-construction
levels. These changes can also be seen in the hydrograph below (Figure
2), which is representative data from a single September storm.
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| Figure 1. Significant changes in runoff
volume (m3/week), runoff depth (cm/week) and peak discharge
(m3/sec/week) after construction was completed.
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Figure 2. Hydrograph of
all three subdivisions in project, showing the larger volume
and rate of runoff from the traditional and control subdivisions,
as compared to the LID. |
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