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Most commercial projects handle storm water
with either an unsightly detention basin or with storage on or below
the parking lot. At North Center Medical, a far better alternative,
bio-retention, utilizes the landscape to detain and filter the storm
water. Most visitors see the beautiful garden spaces without
realizing their true function. North Center Medical directs rain
water from the roof, sidewalks, and some of the rear parking lot
into three bio-retention areas: the employee garden at the northeast
corner of the building, the lawn east of the rear parking lot, and
the front entrance garden.
EMPLOYEE GARDEN: At the northeast corner of
the building, a secluded garden offers employees a quiet setting for
their breaks. This garden also detains and filters rain water. The
diverse plantings are selected for adaptability to varying soil
moisture levels. Spring is welcomed by an array of tulips,
chionodoxa, daffodils, and camassia. In late spring, the employee
garden has iris and roses in bloom. From summer through fall an
impressive display of hibiscus, turtlehead, asters, and daylilies
fills the garden.
BIO-RETENTION LAWN: East of the parking lot,
the gently rolling lawn receives runoff from the asphalt and serves
as an additional detention area. Excess water is picked up by an
under-drain connected to the storm sewer.
FRONT ENTRANCE GARDEN: A fountain rock
welcomes patients at the main entrance to the doctors’ offices. The
fountain is supplied with rain water from the roof. After filling
the fountain basin, excess roof water is dispersed into the entrance
garden landscape. The landscape between the front of the building
and the main (west) parking lot is also a beautiful detention
basin. This rain garden is planted in a diverse mix of shrubs,
flowering trees, perennials, and bulbs, but no lawn. Even the
sidewalks slope gently toward the rain gardens so the runoff water
can be detained and filtered. Three rose cultivars and 17
perennial varieties create ever-changing drifts of color throughout
the entrance garden. The low boulder walls conceal the connecting
pipes under the entrance sidewalks. These pipes enable runoff water
to disperse into the bio-retention areas. Up to 6” of water
accumulates in the bottoms of the bio-retention beds.
This project has demonstrated that responsible
on-site retention of rain water can be integrated into a beautiful
planting design. Besides over 1600 perennials and 90 hardy roses
planted across the site, there are 18 tree species and 23 shrub
varieties to provide texture and color throughout the seasons. The
project owner and his staff planted over 7500 bulbs in the perennial
beds to add color from April to early June. |
