Agriculture Reference
In-Depth Information
rain Garden and related Water Storage or
absorption Strategies
A rain garden is a design strategy to collect and detain surface water
runoff on-site. In the example in Figure 14.34-A, the neighborhood street
and walkway are graded to slope and direct surface water toward the
central planting area. In some cases the rain garden itself is designed
to slope—in the way that a swale slopes—farther downstream to a
larger-capacity retention area. Figure 14.34-B shows a French drain
(item B in the photograph) that was installed to carry excess water from
a rain garden on the upper side of the street to a lower garden down-
stream (item A). Figure 14.35 is a detail section of a bioretention swale or
rain garden similar to the ones in Figures 14.34-A and B.
A
A
B
Figures 14.34-a and 14.34-B
Creation of rain gardens to manage storm water along a neighbor-
hood street in the Netherlands
While not designed as a rain garden, the planting areas in the two
examples in Figures 14.36-A and B are located between the sidewalk and
an adjacent neighborhood street to collect surface water and facilitate
its absorption to the soil. Additional shrub and tree planting could be
installed later and the areas now planted with grass could be graded to
form a basin to increase water detention capacity. Items A, B, and C in
Figure 14.36-A demonstrated three approaches for providing a drive-
way and roadway a porous surface. The materials used in items A and
C are modular concrete units set in a sand base. Item B is a modular
