By VICKI URBANIK

Porter County’s new open space ordinance will allow developers to build more homes on smaller lots, as long as they set aside at least 15 percent of the total acreage for open space.

Unlike the original proposal recommended by the Porter County Plan Commission that basically called for a 20 percent set-aside in subdivisions of at least 30 acres, the new ordinance adopted by the Porter County Commissioners late Tuesday has multiple provisions.

Gone in the final version is the size threshold. Except for “minor” subdivisions of four lots or less, the new open space rules apply to all subdivisions regardless of size.

Also gone in the final document is the open space differentiation between developments with municipal utilities and those without. Instead, the open space requirements are broken down into two main categories: Sites with environmental features such as woods and wetlands, and sites without, such as cornfields or otherwise bare fields.

The ordinance emphasizes the importance of preserving environmentally significant areas for passive recreation, but it also allows developers to build “active” recreational facilities, such as ball fields, if they so chose. Some of the main provisions of the open space ordinance are as follows:

•Sites that do not have environmental features must set aside 10 percent of the total acreage for open space. If the developer opts to include a dry detention facility toward the open space requirement, the total open space must be 15 percent.

•Developments without environmental features that set aside at least 15 percent toward open space can qualify for an “intensity bonus” that would allow smaller homes on more lots. However, the detention facilities used in the calculation cannot be counted toward the initial 10 percent of open space.

•Sites that have environmental features must set aside at least 20 percent of the total acreage for open space. An intensity bonus is allowed if 100 percent of a “priority area” -- such as all the woods onsite -- is preserved for open space or if the priority area combined with other unbuildable areas exceed 20 percent of the total acreage.

If the priority area exceeds 40 percent of the total acreage -- for example, if more than 40 percent of a proposed new subdivision is a forest -- the developer will not be required to set aside more than 40 percent of the priority area. But the priority areas not preserved will not be eligible for the intensity bonus.

Priority areas are defined as those with the most significant environmental features, such as steep slopes, woods, wetlands, dunes, natural lakes and critical wildlife habitat.

Man-made stormwater detention and retention basins cannot be counted toward the 20 percent open space requirement at the sites with environmental features

•The “intensity bonus” reduces the current building lot size based on a formula that takes into account the total number of units, the base density, the unbuildable land and easements.

In areas that are zoned single-family, the lot size may be cut up to 25 percent, with no lot smaller than 8,000 square feet. In rural residential zones, the lots with well and septic cannot be smaller than the 30,000 square feet; lots with municipal utilities can be reduced in size, with the lot width cut to 60 feet.

•A 20 percent open space set-aside is required in all Planned Unit Developments. It was noted at the meeting that Porter County’s PUD ordinance has essentially been struck down in a court ruling and that the ordinance will be rewritten as part of the update of the county’s building ordinances.

•If it is determined that a parcel was clearcut prior to the petition for a new subdivision, the plan commission can require a reforestation plan. The plan commission will use aerial photography to determine if parcels with significant environmental features were altered.

Posted 9/8/2004