Washington County has secured several hundred acres of land in recent years as part of an ongoing effort to preserve open spaces and improve water quality.

Money spent through Land and Water Legacy, a $20 million initiative that county voters passed in 2006, has reached $8.5 million — all of it intended to buy or otherwise secure land and keep it free from development.

“They’re not making land anymore, so the more we can tie up in land conservation, the better,” said Jennifer Vieth, executive director of Carpenter St. Croix Valley Nature Center in Denmark Township.

An 85-acre “conservation easement” surrounding the nature center — the county’s most recent Land and Water investment — permanently shields it from housing construction and any future change. Carpenter will continue to own the land, but the easement ties closely with the county’s interest in protecting natural areas and securing it for trail development.

“The board has been very judicious with Land and Water Legacy, making sure we get the best bang for our buck,” said Gary Kriesel, who chairs the Washington County Board.

But decisions loom as large tracts beckon.

One attractive piece is the 483-acre Tartan Park, a 3M property in Lake Elmo. The Maplewood corporation recently announced its plans to close Tartan Park in December and sell the property, which features three nine-hole golf courses, four softball fields, 12 tennis courts, six picnic pavilions, an archery range, bocce ball courts, a clubhouse and wedding gazebo.

The site already is drawing interest from conservation groups, and Washington County officials have been fielding inquiries from residents, said Kevin Corbid, the county’s deputy administrator.

Tartan Park is located near the county-managed Lake Elmo Park Preserve, the county’s most popular park. The County Board tentatively will review the Tartan property on Tuesday.

The county also is interested in 595 acres of Wilder Forest property in May Township, which includes 200 acres of forest, 56 acres of water and 3.2 miles of shoreline.

“I think what intrigues me about this is the Square Lake access,” said Commissioner Lisa Weik, referring to the county park by the same name. “The Gateway corridor trail going through there is very significant.”

The Gateway State Trail, the most-used trail in Minnesota, ends south of the Wilder property. Eventually, it will be extended through it to William O’Brien State Park and farther north.

Another piece of land drawing county interest is owned by U.S. Bank Trust and borders Belwin Conservancy in Afton. The 60 acres includes 1,200 feet of frontage on Valley Creek, a trout stream considered to be one of the St. Croix River’s premiere tributaries.

The county, too, has been eyeing the McDonald property, which borders and encompasses Silver Lake in May Township. Buying a 100-acre conservation easement — meaning the owner agrees to never develop any portion of the land — has been discussed for years, said June Mathiowetz, the county’s senior planner in charge of Land and Water Legacy projects.

Washington County proposes to buy about 5 acres outright to provide public access to the lake.

Most of those parcels have landed on the county’s list of possible acquisitions, but inspections, appraisals and negotiations sometimes take years, and county commissioners want funding partners to make their Land and Water Legacy money last longer.

Including that kind of “leveraged” money, Washington County and its government partners have invested $21.2 million in open-spaces purchases so far. Of that, $8.6 million is from state and Metropolitan Council grants, and $4.1 million from other funds.

The county spent $5 million from its first bonds issued a few years ago, and has spent $3.5 million of a second $5 million bond issue scheduled this summer.

“What we’d done so far is good, but we don’t have a lot of wiggle room left,” Commissioner Ted Bearth said of the remaining $1.5 million.

Recent acquisitions include the Carpenter property ($2.3 million); 15 acres of the Aiple riverfront property on the north end of Stillwater ($1.9 million); 14 acres of the Palmer property in Stillwater Township for use as parkland ($84,000); 1.5 acres of the Anderson property at Big Marine Lake for use as parkland ($154,000), and 29 acres of La Lake property in Woodbury for use as city open space ($247,500).

The county previously had bought land or easements totaling close to 240 acres.