Using GIS to Manage Rainfall Drainage Structure Maintenance


The City of Lake Forest recently decided that they wanted to
reevaluate and possibly reorganize their storm drainage upkeep
procedures. Currently, the City of Lake Forest is divided into 10
rainfall zones. A streets crew is given responsibility to maintain and
oversee all storm drainage features within their assigned rainfall zone.
Storm drainage features include manholes, inlets, and catch basins. To
ensure that the street crews have similar amounts of features to be
responsible for, the water foreman requested that a map and table be
created to illustrate the amount of features in each rainfall zone. If
the feature are counts substantially unequal then the water foreman may
decide to reassign storm maintenance responsibility.

In GIS the storm drainage utility features (manholes, inlets, and
catch basins) were displayed over the rainfall zones. All utility
features not maintained by the City of Lake Forest were removed. These
included all private and IDOT maintained structures. The Identity tool
in GIS was then used to calculate a count of each storm utility drainage
feature and determine which rainfall zone that feature fell within. The
counts were then organized into a table as well as displayed onto a
rainfall zone map.

The results of this project revealed many disproportioned feature
counts within the rainfall zones. GIS enabled storm drainage features to
quickly and reliably be calculated. The water foreman can now take this
information and reallocate maintenance responsibilities where