| As in most
commercial developments, hardscape design is of key importance.
It’s the hardscape that sets up the circulation pattern for guests,
bringing them to each shop in the development. FRANKENMUTH RIVER
PLACE was no exception in this regard. Water features were
constructed to create the ‘River Place’ theme on this site as well
as help to guide pedestrians through this ‘European Village’
shopping center. In addition, we had to provide access to both
public and private boat docks located on the Cass River.
THE GARDEN
POND DESIGN: This
water feature is part of the entry courtyard garden. It is a small
waterfall spilling into a quiet pond. The challenge here was that a
bridge had to be constructed over the pond. The bridge design
required a continuous footing through the pond area. There were
three arches placed on this footing to create the bridge over the
water. Because the liner had to be completely concealed, there was
no good way to run the liner through these arches.
The best
option appeared to be to build the bridge on top of the liner. Our
concerns were properly sequencing the construction and preventing
punctures of the liner. To make construction even more difficult,
the bridge had to be useable within one week from the start of
excavation, because this was a primary access point to the site.
THE CENTRAL
STREAM DESIGN: The
original concept that the architect had was to construct a low
barrier wall along the walkways adjacent to the stream to keep
people away from the water. Our vision was to keep the water and
landscape accessible so guests could enjoy it more fully.
Fortunately, our vision for this area prevailed.
There were
several benefits to eliminating the barrier walls. One was being
able to direct rainwater flows from the sidewalks into the stream.
This saved the expense of installing catch basins and drains in the
sidewalks. A second benefit was creating a more natural look to the
entire stream and sidewalk area. Since the sidewalks were all
heated, there was no worry about de-icing salts flowing into the
stream or pond. We also eliminated the expense of an irrigation
system by constructing the landscape on top of the liner.
THE
MAIN WATERFALL DESIGN:
When pedestrians approach this site
from the north, they cross the Cass River via a new bridge. At the
end of this bridge, guests are greeted by the thundering flow of
2400 gallons per minute dropping down a twenty foot high, eighty
foot long rapids to the Cass River. Combined with the Cass River,
it provides the visual statement for the ‘Frankenmuth River Place’
theme.
On this part
of the project, we faced numerous challenges. First was the
budget. The original approach was to construct the waterfall with
steel reinforced concrete. As the design progressed, the cost
estimates kept getting higher We finally scrapped the concept
calling for concrete, and went to an EPDM liner covered with large
(up to five by seven feet) stone slabs.
Second, we had
to allow for the potential flooding of the Cass River. On previous
occasions, the flood level has been as much as eighteen feet above
normal water levels. To maximize the ability of this water feature
to handle flood waters, massive pieces (up to four tons each) of
limestone were used during construction. To support all this
weight, we started with a steel sheet piling driven in at the edge
of the river. This allowed a concrete footing to be poured behind
the sheet piling and below the water level of the river.
Third, the
effect that we wanted to create required a flow rate of 2400 gallons
per minute at 20 feet of vertical head. This meant two submersible
pumps, fifteen horsepower each, had to hidden somewhere. We
designed a pump well with an access hatch into the new boat dock
that was being installed adjacent to the base of the waterfall.
From this well, two 10” diameter pipes carried the river water to
the top of the waterfall.
With that much
water, we had to have a way to disperse the flow at the top of the
waterfall or it would look like it was shooting out of a pipe
instead of flowing out from under the simulated bridge. This was
accomplished by pouring the "bridge" abutments and foundation to
create a dispersal tank. As the water flows into the bottom of this
tank, the velocity drops. By the time it flows out the top of this
tank, it looks like a continuation of the stream from the other side
of the "bridge."
CONCLUSION:
The construction
schedule for landscape and hardscape on this project was compressed
to two months. This meant having three landscape contractors, two
excavating contractors, and an irrigation contractor on site at the
same time. In addition, the interiors and exteriors of the
buildings were still under construction. This meant a high degree
of cooperation from all the trades working on the site. It also
meant a great deal of prior planning on our part.
All the
pavement elevations and drainage patterns had to be determined in
conjunction with designing the water features. The limited spaces
created tight tolerances, and required a great deal of site
supervision to execute. All the planning paid off in the finished
project.
The
combination of architecture and special features make guests feel
they are in a real European village. The infrastructure is well
hidden and operates with minimal headaches. As a result, business
is good and the owners and tenants are happy. We faced a lot of
challenges with this project, but I’m proud to have been involved. |