GIS and Stormwater Management

Stormwater Management is often referred to as the redheaded stepchild of municipal government. Lacking the political clout and daily exposure given to other departments such as parks, police and fire, and other services such as street repairs, sidewalk extensions, and trash removal, the absence of a comprehensive program is seen as a problem only when it rains. Officials responsible for stormwater management dread going to work on rainy days expecting the deluge of phone calls from citizens complaining of rising floodwaters. Constituents also contact their council representatives demanding action to solve their drainage problems. But as quickly as the waters rise and fall so does the demand for solutions and by the time a plan for stormwater management is completed, memories of the problems have evaporated and the implementation is viewed as a waste of the taxpayers’ money.

Beyond the lack of funding, in most communities, the problems with stormwater management can be attributed to several factors: lack of a central person or department in charge of stormwater, inadequately designed infrastructure unable to handle the demands placed upon it, lack of maintenance of the stormwater system, and decaying infrastructure at the end of its useful life.

Municipalities often diffuse the responsibilities of stormwater management over several departments. Planning Departments are in charge of enforcing floodplain management and erosion control ordinances as new developments petition for required permits. Engineering departments are in charge of completing studies and designing projects to address flooding problems. Street Departments are in charge of maintenance and repairs on the collection system. This separation of responsibility makes Master Planning difficult. Additionally, in all cases, these responsibilities are secondary to the primary duties of each department and are preformed as a reaction to an existing problem. For example, during a street repair, a field crew discovers the pothole is caused by a collapsed section of pipe under the road. In some cases, the solution to the pothole problem would be to fill the pipe with concrete, in others replace the section of pipe. Because the focus of the Street Department is road repair very little effort is made to maintain the existing pipe or verify the condition of the additional sections of pipe.

Even if during the repair the faulty section of pipe is replaced, it is unlikely that the capacity of the pipe is checked to ensure it can adequately handle the runoff reaching it. With stormwater a divided and secondary responsibility, often under-sized infrastructure is installed during repairs and with new development. Cities and towns that lack a central stormwater department also tend to lack clear and precise design standards for sizing stormwater infrastructure. This lack of criteria results in municipalities not checking the capacity of pipes and culverts during repairs and replacement projects, noting any changes in the upstream watershed and private engineering firms submitting varying standards for private developments.

Many communities also tend to be reactive in their maintenance of the stormwater system. Instead of developing an ongoing, daily maintenance program, they rely on citizen complaints of an immediate drainage problem. In a 1992 survey of North Carolina cities, twenty percent stated local flooding problems were due to a lack of maintenance. Surveys of detention ponds in Maryland from 1986 to 1992 indicated a major reason for high rates of failure was poor or nonexistent maintenance.

Another problem is much of the stormwater infrastructure in the U.S. is at the end of its useful life. Most communities have either celebrated or are close to celebrating their centennial birthday. This means the original bridges and culvert, built to carry the roads over creeks and streams, is also close to one hundred years old. If it is not original, much of the infrastructure in the core parts of a community is of the WPA era and is between sixty to seventy years old. With a service life of seventy-five to one-hundred years, coupled with a lack of maintenance, many parts of the stormwater conveyance system are an underground time-bomb waiting to collapse. Back to back culvert failures in Bloomington, Indiana in 1995 and 1996, under roads and homes, prompted an inspection of the major storm tunnels in the city. The 1997 report inspected twenty percent of the culverts over three feet in diameter and identified over twelve million dollars of needed repairs to prevent future collapses.

Whatever the reason - lack of a Master Plan, under-sized pipes half full of debris or culverts collapsing under the street - the flooding problems in our communities can be traced back to a lack of a financially stable, permanent program to address all stormwater issues for a community.

In September 1998, facing many of the problems mentioned above, the City of Bloomington, Indiana established a Stormwater Utility as a permanent program addressing the problems associated with runoff in the community. Title 36-9-15 of the Indiana Code defines stormwater as sewerage and the Stormwater Utility was incorporated as part of the exiting Wastewater Utility. This parent-child relationship has many benefits including an existing billing and collection system, established business practices, and shared resources in administration, engineering, construction and maintenance. Using existing resources allowed for a lower bill to the customer ($28.20 per year for a residential customer) while generating approximately $1.0 M per year in operating revenue. With the service area set at the municipal boundary, the stormwater utility responsibilities currently include: maintaining a fair and equitable user-fee for the customers, reviewing new development to ensure consistent standards are met, performing daily maintenance, and small additions to the existing system, investing in large capital projects to repair the backbone of the conveyance system and preparing to address EPA’s Phase II NPDES Permit requirements for stormwater. In the future, the utility may expand its scope to include maintenance of stormwater management ponds, floodplain management and erosion control enforcement.