storyhill.net,
Nov. 20, 2007
Freeway
plan increases runoff, paves over floodplain
Milwaukee County hit hardest
Nov.
20 -- The
proposed $1.9 billion I-94 north-south expansion project would increase
paved-over freeway land in the corridor by almost almost 50% in Milwaukee
County, according to the draft Environmental Impact Statement for
the project.
The
amount of impervious I-94 freeway land would increase from 10.3 million
square feet to 15.4 million square feet, a 49.7% increase, according
to the EIS.
That
is more than the combined pavement increases in Racine and Kenosha
counties in Wisconsin and Lake County in Illinois, the other counties
affected by the proposed expansion project.
"The
amount of storm water runoff is expected to increase proportionately
to the increase in impervious surface (that is, pavement)" according
to the EIS.
The
project overall would increase freeway-related pavement from 37 million
square feet to 46.4 million square feet, a 25.4% increase.
Some
of the Milwaukee County land to be filled -- about 174,000 square
feet -- is floodplain, or land that is susceptible to flooding. Increasing
the amount of land that cannot absorb water raises flooding risks.
Runoff
from the hard surfaces of freeways also is generally highly contaminated.
Chemical
pollutants from cars can poison water, vegetation and associated aquatic
life.
The
document does not specify the steps the state would take to reduce
pollution from the increased runoff. It says most storm water quality
control in Milwaukee County would be achieved through grass ditches
near the freeway.
The
EIS also does not specify any steps the state would take to reduce
potential flooding.
The Milwaukee Metropolitan Sewerage District
is involved in major, expensive flood control and water quality efforts
in the Milwaukee area. MMSD spokesman Bill Graffin said district officials
say WisDOT has not been in touch with them about the North-South project.