1/21/2010
Reed Hollinshead
ITD Communication
208-334-8881
reed.hollinshead@itd.idaho.gov
I-84 drainage ponds improve safety, extend highway life
BOISE -
No, that's not another road paralleling I-84 west of Robinson Road. It's not
the future site of a rest area, either. The large, excavated rectangular depression (it's about 8 feet deep) is actually a drainage
pond, needed to get the storm water off the surface of the roadway for the
safety of drivers and to make the roadway last longer.
When the median between the eastbound and westbound lanes of I-84 was dirt, the
water could pool there and would eventually seep into the ground and dissipate.
However, now that the interstate median has been paved over, the water cannot
be absorbed - it has to be removed from the surface via piping and deposited in
these drainage ponds adjacent to the road.
The pits will be excavated and seeded with grasses to prevent erosion. What
looks like a big mud pit today will be a grassy depression in future years.
There are
three locations where motorists will initially see new drainage ponds:
- South of
I-84 and west of Robinson Road (click here for photo)
- North of
I-84 between Robinson and McDermott roads
- Near the
new University of Phoenix, (near Boondocks Fun Center/Waterpark) south of I-84,
west of the Meridian Interchange.
In
addition, there are drainage ponds already built or soon to be built for the I-84
projects along the I-84 Treasure Valley Corridor:
- The Ten Mile Road Interchange will have four ponds, in the four quadrants of the
ramps.
- The Garrity Boulevard Interchange will
have three ponds, one west of the Idaho Center Boulevard (between the westbound
on-ramp and Ridgecrest Road), the second north of I-84, east of Dan Wiebold
Ford, and the third actually will be an expansion of an existing pond in the
southeast quadrant between the ramp and I-84.
- There
also will be five ponds in the Franklin-to-Garrity
section of I-84 in Nampa one south of I-84 between 11th Avenue and the UPRR
Railroad bridge, one between 11th and Garrity south of I-84, one north of I-84
between the Phyllis Canal and the railroad (just east of the KIVI Channel 6
building), and the last two are in the northeast and southeast quadrants of the
Franklin Interchange.
In
addition:
- The Orchard Street Interchange has three
ponds. They are located between the ramps and the freeway in the northeast and
southwest quadrants, plus one is adjacent to Wright Street.
- The Vista Avenue Interchange project
features three conventional ponds between the ramps and the right-of-way
(outside) quadrants in the northeast, southeast and northwest.
- Drainage
for the ongoing Cole-to-Broadway
widening on I-84 will actually be done through an underground system
(buried chambers). These chambers run along the outside of the freeway on both
sides. In addition, there are chamber ponds in all four quadrants at Vista
and the northwest and southwest at the Broadway Avenue Interchange, between the
ramps and the freeway.
- The Meridian Road Interchange has two additional ponds.