[Vision2020] Palouse Mall

[bill london]

    The Palouse Mall is moving dirt in the planting strip adjacent to 
the Moscow-Pullman Highway.  The V-shaped ditch along the road has been 
covered in dirt and a culvert system has been installed.
    This is all in response to the Mall's illegal cutting of trees and 
bushes four years ago, and the replanting plan that was negotiated over 
that four-year period between the city, the mall, the Idaho Department 
of Transportation and the UI.
    I understood that (as part of the plan for the replanting of that 
strip) the grassy ditch along the highway would remain -- so when that 
ditch disappeared, I started asking questions at the city.
    This is what I found out:
    What was there before was a ditch.  Runoff water would collect in 
that ditch and dump into the creek.  A far better system for aquifer 
recharge and the gradual absorbing of rainwater into the ground is a "swale"
    A swale is a very shallow ditch, with a culvert system installed 
within it.  The culvert has inlets that are just above the ground 
level.  So when water enters the swale in moderate amounts, it puddles 
there and slowly is absorbed by the ground.  When water enters the swale 
in large amounts (like a big rainstorm), the water flows into the inlets 
and then into the culver and then into the creek.
    What has been installed in most of the planting strip is a swale.  
And it sounds to me like that is an improvement.
BL