The Graham Arm legal drain is seen looking south along Earlywood Drive on March 29 in Franklin. Development in areas connected to legal drains like Graham Arm are part of the reason behind why the county is updating its watershed maps. Since the 1980s, the county has grown by over 109%.
NOAH CRENSHAW | DAILY JOURNAL
Johnson County’s population has grown by more than 109% since the 1980s and that has come with challenges for the county’s watersheds.
The county has more than 49 combined watersheds — creeks, ditches, drainage ways and sub-surface tiles — all of which drain runoff from various areas of the county. All properties that connect to a legal drain should pay an assessment fee for maintenance on the drain, but not all do, said Gregg Cantwell, county surveyor.
That’s because so much land has been developed since the last time the county surveyor’s office completed a full drainage assessment. The last full assessment was completed in the 1980s — when the county’s population was between 77,000 to 88,000. The county has grown by over 109% since then, Cantwell said.
The surveyor’s office and the Johnson County Drainage Board have been working over the last year and a half to present the need and secure approval for the full update. The plan has five phases: map updates, new rates, public hearings, preliminary studies and reconstruction. The first three phases could cost the county up to $210,000. Phases four and five, which are based on estimates from studies conducted for the reconstruction of the Scott-Highbridge Legal Drain in Greenwood, could cost up to $301.9 million, county documents show.
The plan was approved by the Johnson County Drainage Board unanimously in January and was presented to both the county council and commissioners in February.
Recent developments on the east side of Johnson County near Interstate 65 make clear the need for the assessment, Cantwell said. The flat topography of the eastern part of the county requires more drainage infrastructure than hilly White River Township, where development had been centered previously, he said.
“Boom. The east side of that whole corridor of Interstate 65 just popped,” Cantwell said. “The majority of the county’s regulated drains are in that pocket north and east of (the area).”
A majority of the county’s regulated drains are classified as rural, meaning they are designed for runoff from farmland. They’re not urban drains, which are designed for runoff from commercial, industrial and residential developments. Because of the county’s growth, a majority of rural drains need to be reclassified and upgraded to urban drains, Cantwell said.
“It’s growing pains. It’s the process of getting everything updated,” he said.
The first phase, updating the watershed maps, is needed to capture the watersheds and to show who all is benefiting from a particular watershed. There are some developments that may technically be part of a legal drain but are not contributing to the annual maintenance of the drain, Cantwell said.
Right now the county is preparing to wrap up the map updates. The county had contracted Burke Engineering to update the maps, and the preliminary maps are expected to be delivered to the surveyor’s office this week, Cantwell said.
Once the maps are done, the county will need to have public hearings to inform property owners who may not have been included under the original maps that they need to pay a maintenance fee. Affected property owners can attend the meeting to hear more about the process, he said.
Homeowners and businesses are not the only groups to be affected by changes. Under Indiana law, every square inch of land within the watershed has to contribute to the maintenance of the watershed, even local governments. Municipalities that aren’t paying their full portion of the assessment fee will be captured with the updates, he said.
Following the initial public hearings, county officials will determine what annual maintenance would be needed and how much it would cost annually for each property. This will be followed by an additional set of public hearings, Cantwell said.
“If you’re paying the same thing you were 30-40 years ago, the assessment is going to be higher. It has to be,” Cantwell said.
Many properties have not been properly assessed for years, said Kevin Walls, county commissioner and drainage board member.
“When we’re looking at all these ditch assessments and what we have in these funds, they’re all red,” Walls told the county council last month. “That’s what really struck us up to do this.”
Officials also need to consider how it could affect the stormwater utilities in Franklin and Greenwood, Cantwell said. Both cities’ utilities maintain the infrastructure to get the water to the ditch and charge residents for that service. At some point, the surveyor’s office may need to meet with city officials to make sure they are not overburdening residents and businesses with fees, he said.
The next phase involves studying each drain to determine where water is coming from and determine if needs to be reconstructed. The county has already begun this step for the Amity watershed, which stretches from east of Interstate 65 in Franklin to Amity, he said.
Because there is hundreds of acres of development planned east of I-65 in Franklin, there is an urgent need to evaluate the drain, Cantwell said. This will allow the surveyor’s office to potentially get ahead of drainage problems, he said.
Cantwell says he plans to hold town hall meetings areas in densely populated areas of the county. The plan is to hold the meetings before the final public hearings, he said.
“It’s drainage — it’s ugly; it’s not pretty,” Cantwell said. “It’s not a pretty trail with pretty lights and pretty signs and trees; it’s just an ugly old ditch. Nobody really thinks about it.”
Many of the tiles and ditches date back to the county’s founding in 1823 when the east side of the county was described as a swamp. Early settlers dug the ditches and plowed the land, and the ditches were designed for farming, Cantwell said.
“Now we’re putting houses and streets and industrial (developments) into that same old ditch, and that just doesn’t work,” he said.
There has been exponential growth across the county over the last 20 years, and it’s only going to get worse as Interstate 69 comes in. Johnson County needs to get ahead of it, Walls said.
“It’s here. We want to get in front of it because if we don’t it’s going to be a catastrophe,” Walls said.
