Mary McCawley
Landscape Architect
LEED AP
HDR Architecture
Bruce Maine
Sustainable Design Consultant
LEED AP
HDR Architecture
Metro Health Hospital in Wyoming Michigan has committed to obtaining LEED certification for its entire 170-acre site. When full operations open later this year, Metro will feature a number of processes not normally used in hospital design. These include a 60,000-square-foot vegetated roof and 11 vegetated islands for infiltrating stormwater runoff. In addition, HDR designed a pair of “healing gardens” to complement conventional methods of treatment and rehabilitation.
The green roof and infiltration BMPs, Best Management Practices, in two of the parking lots will be monitored to test the ability of BMPs to manage the quantity and improve the quality of the stormwater runoff. The priority focus of the green roof monitoring system will be stormwater runoff quantity control, and the bioretention swale monitoring system will primarily focus on water quality issues. The vegetated roof will be installed in the spring of 2007 on the hospital outpatient building. The vegetated BMP, an American Hydrotech green roof system, is comprised of several inches of engineered soil mix and multiple varieties of sedum to control storm water through absorption and evapotranspiration. Sedum and alliums are being used because they are drought-resistant perennials that do not require trimming, mowing, or thick layers of soil. Almost 200 hospital patient, waiting, and treatment rooms overlook the vegetated roof.
The green roof will serve as the test site. Performance criteria of the green roof will be compared to an energy-efficient white membrane (Energy Star) rooftop, which will serve as the control site. A tripod-mounted weather station is mounted on the green roof to record and track local, ambient weather conditions. The station is equipped with the following instrumentation:
- thermal probe (with radiation shield) — to measure ambient air temperature
- hygrometer – to measure ambient relative humidity
- a tipping-bucket rain gauge (with heater) — to measure total precipitation
- an anemometer and wind wane — to measure wind speed and direction, respectively
Eleven vegetated islands — seven grassy swales and four bio-retention swales (or rain gardens) — have been installed in the visitor and employee parking lots to infiltrate stormwater runoff. The performance of three grassy swales and three bio-retention swales will be monitored. A grassy swale is designed to move water along a planted swale. The bio-retention rain gardens are designed to be depressions to hold water for a short time in pockets of an alter soil mix and planted with adaptable deep rooted rain garden plants. Both swales operate on the principle of using plants to slow and filter water.
Parking lots are graded so that stormwater runoff will sheet-flow towards one side of each of the test sites. “The stormwater enters each test site through a series of inlet channels cut into the pavement curb at regular intervals along the longitudinal edge of the island. These inlet channels represent the sampling input points. After infiltration and filtration through the turf swales or bio-retention swales, the water enters a 4-inch diameter drainpipe that runs the length of each island and discharges to a retention pond down slope.” A monitoring station, is situated near the end of the island, and serves as the sampling output point.
The site was large enough to incorporate an overland drainage system — bioswales — for most of the parking lot bays. The idea was simple: manage your own storm runoff on your site and not allow it to run into and possibly pollute open waterways. It is also important to note that the swales serve a dual purpose of allowing adequate space for the planting of significant trees to help control the heat island effect of the pavement surrounding the swales. A $400,000 grant from the Michigan Department of Environmental Quality, Surface Water Quality Division, underwrote much of the cost of the vegetated roof and the 11 vegetated islands. The project will result in improved water quality and decreased burden on the municipal wastewater treatment facilities. The quantitative and qualitative evaluation data collected in this demonstration can be used to develop performance standards, which can help promote the use of vegetative BMPs in Michigan municipalities. This will be the first study to yield comparison data between different BMP technologies – vegetated roof versus energy-efficient white membrane roof or turf swales versus bioretention swales. Data derived from the project will demonstrate a number of things. For example:
- adequately measure the environmental benefits of implementing these technologies
- conduct an economic analysis of installing these technologies
- support the scientific validity of new measurement methods
- provide evidence to statewide businesses and municipalities
- establish objective performance standards
Results from this demonstration will help inform an empirically valid implementation model and tested measurement methods. Implementing BMPs at Metro affords us a unique opportunity to stimulate replication among other local businesses. Metro has stipulated in its deed restrictions that all businesses in the 170-acre Metro Health Village become LEED-certified. Therefore, the health village will have the highest concentration of LEED buildings from multiple sectors (e.g., banks, retail shops, restaurants, physician offices) anywhere in Michigan and perhaps the entire nation. Furthermore, because many of the businesses located at the Metro Health Village are national retailers, the benefits they witness and experience from this demonstration project may elicit replication in other locations nationwide.
While not part of the LEED-certification program, the two “healing gardens” speak to a different need that is being increasingly addressed by modern medical facilities. An overwhelming majority of patients experience heightened anxiety as a result of illness, medical treatment, and hospitalization, and healing gardens are becoming an increasingly popular way to counteract illness-related stress and anxiety. The larger of the two covers 9,504 square feet garden and is designed with a primary focus on emotional and psychological restoration. The garden was designed with “the journey of life” in mind as life is filled with paths that wind, intersect, and straighten, all returning to the original starting place. The garden invites visitors to pause for reflection and experience the therapeutic and rejuvenating effects of serene views, calming scents, pleasing textures, and soothing sounds.
The garden features a variety of perennial flowering plants, shrubs, trees, and ferns, each carefully selected and arranged to impart maximum therapeutic benefit to patients. The garden design includes concrete seat walls formed around a spacious lawn and a pond with a waterfall, aquatic plants, and a variety of fish. Benches, decorative stepping stones, a children’s interest area, and movable outdoor furniture will allow for creative and multipurpose use of garden areas. A wide paved path allows patients in wheelchairs or with walkers to reconnect with nature through the sights and sounds of the healing garden.
A smaller, 1,090 square-foot garden serves as a meditation area. Its purpose is to provide patients and visitors with a calm and peaceful place to reflect and relax. A bubbling fountain with a reflective basin provides visitors with the soothing sound of moving water. Much like the large healing garden, the meditation garden has seat walls, movable tables and chairs, and intentional lighting, but is a smaller, quieter space than the other garden, which invites silent reflection and meditation.
Research shows that many people have negative emotional and psychological reactions to poor health, especially patients suffering from chronic or terminal illnesses. But research also shows improved treatment response with patients who have access to natural features such as gardens with seasonal interest, fragrant flowers, seating areas, sculptures, ponds, and other water features. Scientific research on role of gardens in healthcare setting shows significant reductions of stress and improved outcomes. Clinical research demonstrates improvement in blood pressure, stress levels, reported pain levels, and length of stay.
