Calvert County will now pay $6,500 for each development right a farmer is willing to sell, the latest increase in a decades-old program that shapes where homes can be built and which fields and forests stay open.
The Board of County Commissioners approved the new price Aug. 18 on the recommendation of the Agricultural Preservation Advisory Board, which reviewed recent private-market sales. The price replaces the $6,230 set in September 2025 and applies to two county programs: the TDR Reserve, which buys rights and resells them, and the Purchase and Retirement Fund, which buys rights and takes them off the market for good. Commissioners have budgeted $12,950,067 for retirement purchases this fiscal year.
What a TDR is
A transferable development right, or TDR, separates the right to build from the land itself. Since 1978, Calvert has given owners of farm and forest land in the county’s rural areas development rights based on their acreage. Under the program’s formula, an owner generally gets one TDR per acre, minus five for each house already on the property.
When a landowner enrolled in an Agricultural Preservation District sells those rights, the land is permanently restricted from development. It stays farmland or forest. The buyer, usually a builder, can use the rights to build more homes than base zoning allows in areas the county has marked for growth, such as its town centers and certain residential districts. The number of TDRs needed for each extra home varies by zone and housing type. In rural zones it has historically been up to five per extra home.
The system makes development pay for preservation. Instead of the county buying every farm outright, builders who want more density buy the rights from farmers.
Two county programs, two different jobs
Calvert doesn’t leave the whole market to private deals. It runs two programs, and they handle money very differently.
The TDR Reserve is a revolving fund, created in 2021. The county buys TDRs from farmers at the set price, now $6,500, and holds them until a buyer wants them. It then resells them at the same price plus a 1% administrative fee, or $6,565 per right at the new price. In principle the fund pays for itself. It also gives farmers a guaranteed buyer and gives builders a guaranteed supply, with no need to track each other down. Sales are first come, first served, there’s no cap on how many rights an owner can sell, and purchases depend on available money and supply.
The Purchase and Retirement Fund, known as PAR, works differently. Since 1992, the county has used public money to buy TDRs and retire them permanently. A retired right is never used to build anything. The land is preserved, and the county pays the full cost with nothing resold. This is the program behind the nearly $13 million in this year’s budget. At $6,500 per right, that’s enough to buy roughly 2,000 TDRs, roughly 2,000 acres if every dollar were spent.
Where the money goes
Every dollar spent through either program goes to the owners of preserved farm and forest land, mostly longtime farm families. For many of them, selling development rights is a way to get value out of their land without selling it or subdividing it.
Taxpayers fund the PAR purchases. Builders fund TDR Reserve purchases when they buy rights back from the county. Homebuyers pay indirectly, because the cost of the rights is built into the price of homes in growth areas.
The price has climbed steadily. The county paid $5,500 per right in 2023, raised it to $6,000 in 2024, then to $6,230 in 2025. This year’s $6,500 is up about 4.3% from last year and about 18% from 2023.
Why it matters to residents
Calvert’s TDR program is one of the main tools behind its rural character. The county set a goal of permanently preserving 40,000 acres. By 2019, about 30,000 acres had been protected through all of the county’s preservation programs, according to the American Chestnut Land Trust.
Economists at Resources for the Future studied the program’s first two decades and found it worked better once the county began buying rights every year at a fixed price. That steadied prices and gave farmers confidence the program would last.
Higher prices are meant to keep farmers selling as land values rise. They also raise costs for builders, and some of that can reach buyers in Prince Frederick and the other town centers. By 2015, the county had about 12,300 unused TDRs on the market and only about 20,000 preserved acres from the TDR program, and commissioners moved to reduce the number of TDRs builders needed in some areas.
Neighboring St. Mary’s County shows how differently a TDR market can play out. There, builders mostly pay the county a fee rather than buying from farmers, and no private TDR sales were recorded for three straight years.
How to buy or sell
Applications for buyers and sellers are available from the Calvert County Department of Planning & Zoning at CalvertCountyMd.gov/CalvertAgPres. Completed applications can be emailed to Rural Planner Jennifer David at Jennifer.David@calvertcountymd.gov or mailed to:
Department of Planning & Zoning
Attn: Jennifer David
150 Main St.
Prince Frederick, MD 20678
