LEWISTOWN — Farmland preservation is not all about agriculture’s economic impact on the community, although that is important, Dan Dunmire told members of Lewistown Rotary Club at its Tuesday meeting at the Lewistown Country Club.

Dunmire, district manger for the Mifflin County Conservation District, spoke to the club about the purpose and activities of Mifflin County’s agland preservation board.

Other factors in preserving ag land include food production, the esthetics of open land and the beauty of farmland, environmental issues, such as aquifer recharge, and water quality issues, Dunmire said.

He cited paving of large areas, such as parking lots, as interrupting the natural trickle of water that recharges the aquifer.

“Paving has a pretty drastic effect on water quality. I think everyone agrees we need farmland preservation but, unfortunately, the best farmland often becomes the first to be developed,” Dunmire said.

“The best features of farmland make it more conducive to development. We’re not against development, (but) we are trying to preserve the best we have here and possibly direct development to other areas,’’ he said.

Dunmire traced the farmland preservation movement from the passage of the Ag Security Act in 1981, which allowed farmers to set aside acres devoted to agriculture into Ag Security Areas. This land then enjoyed a measure of protection from nuisance complaints for normal agricultural practices and some protection from eminent domain.

“Through the 80s, most of Mifflin County’s townships did create Ag Security Areas,all but Brown, which, ironically, has some of the best farmland in the county and a lot of development.’’ he said.

The purchase of conservation easements — commonly called development rights — began in 1988 in southeastern Pennsylvania and spread to Mifflin County by 1992, when the seven-member county preservation board was appointed by the Mifflin County Commissioners.

Originally funded by a $100 million bond issue, the movement was later funded by a two-cent tax on a pack of cigarettes.

To date, 55 Pennsylvania counties participate in the conservation easement program. This has resulted in the preservation of 3,450 farms totaling 382,845 acres, at a cost of $901.2 million.

Mifflin County has preserved 15 farms totaling 1,661 acres, at a cost of $1,708,564, Dunmire said, averaging one farm per year preserved.

“They aren’t cheap, but we are preserving farmland forever at that price,’’ he added.

Dunmire noted the value of farmland minus the development rights was expected to diminish, but the opposite has proven true.

“Experience has shown us that the value of the ag land tends to go up. If somebody is looking for land to farm, there is no better guarantee that it’s going to stay in farming — and farmers will pay a premium for that,’’ he said.

Although Mifflin County’s share of state funding — $65,000 — and a $30,000 allocation from the county commissioners is “low this year,’’ there are federal farmland preservation funds that have augmented that figure, Dunmire said.

He also discussed the criteria that go into the selection of a farm for preservation. The farms which have been offered by application are ranked on factors including soil assessment, land evaluation and development pressure.

The top-ranked farm is assessed for market value and farmland value. The difference is the easement value. In Mifflin County, that figure typically runs between $1,500 and $2,000 per acre, Dunmire said.

“Based on the easement value and the money we have available, we make an offer. If the value is more than we can afford, we typically offer a percentage, maybe 75 percent,of the easement value, and the unfunded part is considered a donation. Given time, that can be used as a tax deduction,’’ he said, adding that proceeds from the sale of conservation easements are considered taxable income. The money can be paid as a lump sum or in installments.

Dunmire said the purchase of an easement takes about a year, with all the paperwork and criteria to be met, and Mifflin County has two easement purchases pending with one purchase expected soon.

He noted that $140,000 of a $1 million Growing Greener grant has been earmarked for farmland preservation in Mifflin County.

The farmland preservation program is co-administered locally by the conservation district and Cooperative Extension.

Dunmire described the conservation district as a local government body that exists to conserve and preserve the natural resources of the county.

He also outlined several programs administered by the district, including erosion and sediment control, which largely affects developers, but said about half of their programs are with agriculture.