NYC DEP's Land Acquisition Around the Ashokan Reservoir, Ulster County

How the reservoir came to exist: a genuinely significant local history

Built between 1907 and 1915, the Ashokan Reservoir sits almost entirely within the Ulster County towns of Olive and Hurley. Its construction required flooding land that had supported roughly a dozen established communities -- more than 500 dwellings, dozens of stores, several churches and schools, sawmills, and a gristmill -- and displaced approximately 2,000 residents from land their families had farmed, logged, and quarried for generations. This isn't a footnote: it's the direct reason the towns bordering the reservoir today carry the land-use patterns they do, from the Route 28 Scenic Byway along its north shore to the specific, ongoing NYC land-acquisition activity described below.

The Ashokan watershed: 155,340 acres across three counties, most of it in Ulster

The reservoir's full drainage basin covers roughly 155,340 acres spanning eleven towns across Ulster, Greene, and Delaware counties -- in Ulster County specifically, that includes Denning, Hardenburgh, Hurley, Kingston, Marbletown, Olive, and Shandaken. Since a 1997 program authorization, New York City has been actively acquiring land in fee and through conservation easements across this basin specifically -- one program report placed the figure at almost 10,000 acres acquired within the Ashokan basin alone as of the mid-2000s, including a single 1,116-acre acquisition on Tonshi Mountain. Given that NYC's watershed land-acquisition program has continued operating in the two decades since that report, the true current total for the Ashokan basin is very likely meaningfully higher -- this page does not update that figure with a guess, and a buyer should get DEP's current total directly rather than rely on the 2005-era number cited here as historical context.

What this means if you're evaluating land near the reservoir

A meaningful share of the private land remaining in the towns immediately around the Ashokan Reservoir has either already been sold to NYC (in fee, meaning the city owns it outright and it's off the private market entirely) or placed under a permanent DEP conservation easement (meaning the current owner keeps the land and certain permitted uses -- typically forestry and limited agriculture -- but has permanently sold away development rights). If you're looking at a parcel in Olive, Hurley, Shandaken, Marbletown, Denning, Hardenburgh, or the Ulster County portion of Kingston (the town, not the city), don't assume it's unrestricted just because it's privately listed -- get a full title search, and specifically ask whether a DEP easement is already recorded against it or an adjacent parcel that could affect access or use.

Separately, new or modified septic systems in this specific watershed area can require NYC DEP review in addition to the county Health Department's standard Appendix 75-A process -- and DEP partners with the Catskill Watershed Corporation to help fund septic system rehabilitation for qualifying homeowners in the broader West-of-Hudson watershed towns, which can be a meaningful resource if you're evaluating a property with an older or failing system.

What to check before buying near the Ashokan basin

1. Get a full title search on any parcel in Olive, Hurley, Shandaken, Marbletown, Denning, Hardenburgh, or the town of Kingston -- a recorded DEP conservation easement is a permanent restriction that runs with the land regardless of listing description.
2. Ask NYC DEP's Bureau of Water Supply directly for the current, up-to-date Ashokan basin acquisition total and whether the specific parcel or an adjacent one is in an active priority-acquisition area.
3. If a septic system needs to be built or replaced, ask the Ulster County Department of Health whether DEP watershed review applies to this specific parcel, and whether it may qualify for Catskill Watershed Corporation rehabilitation funding.
4. If the parcel or a neighboring one was part of the original early-1900s reservoir-construction displacement history, understand this is now over a century of settled title -- it does not itself create a present-day claim, but confirming a clean chain of title is still standard due diligence.