New York
Buying Land in Sullivan County, New York
Sullivan County sits in the Catskills, home to the Neversink and Rondout Reservoirs that supply part of New York City's drinking water -- and one of just five counties statewide where NYC's Department of Environmental Protection has direct regulatory and land-acquisition authority layered on top of ordinary county and town rules. Here's what a buyer needs to check before purchasing.
Government: a 9-member County Legislature and County Manager
Sullivan County is governed by a nine-member elected County Legislature and an appointed County Manager, with the county seat at Monticello (also the seat of the Town of Thompson) and a secondary government office presence in Liberty. The county comprises fifteen towns spread across the western Catskills. As in the rest of New York outside the Adirondack Park, zoning authority rests entirely with each individual town -- the county has no zoning code of its own.
The NYC Watershed layer: septic and land use get an extra check
Sullivan County is one of five New York counties -- alongside Delaware, Greene, Schoharie, and Ulster -- that fall under the New York City Department of Environmental Protection's Watershed Rules and Regulations, a distinct layer that exists because the county's rivers and reservoirs (principally the Neversink and Rondout, discussed below) supply part of New York City's drinking water. Within the DEP's regulated watershed area, new or modified septic systems generally require DEP review and approval in addition to the standard county Health Department process under Appendix 75-A, and certain other land-disturbing activities near watercourses can trigger additional DEP permitting. Confirm with both the county Health Department and NYC DEP's Bureau of Water Supply whether a specific parcel sits inside the regulated watershed boundary before assuming a standard septic process alone applies.
The Neversink and Rondout Reservoirs, and NYC's land-buying program
The Neversink Reservoir sits entirely within the Town of Neversink in Sullivan County, and its water flows through a tunnel to the Rondout Reservoir -- itself split between the Town of Neversink in Sullivan County and the Town of Wawarsing in Ulster County -- where it joins water from the Pepacton and Cannonsville reservoirs to form the west-of-Hudson component of New York City's water supply. Since a 1997 Memorandum of Understanding, NYC DEP has run an active Land Acquisition Program purchasing both fee-simple land and conservation easements across the broader Catskill/Delaware watershed, which includes Sullivan County, with an original watershed-wide target of 355,000 acres backed by a $250 million city commitment. This research pass could not confirm a Sullivan-County-specific acreage total for how much of the county NYC now owns or holds under easement -- see our dedicated page on this program for what's confirmed, what's not, and what to check on a specific parcel.
A note on Resorts World Catskills and the local tourism economy
Sullivan County's local economy leans heavily on tourism -- $969 million in traveler spending in 2023 by the county's own reporting -- anchored in part by Resorts World Catskills, a large casino and resort complex that opened near Monticello in 2018. The casino has driven real regional development and short-term-rental demand, but has also faced serious financial underperformance, culminating in a 2026 deal where a county-affiliated development corporation issued a $585 million municipal bond to acquire the resort's non-gaming assets. This is important context for anyone evaluating land near Monticello for recreational-land or short-term-rental purposes, but it's a single-operator financial and economic-development story rather than a generalizable zoning or permitting rule, so it's noted here rather than treated as its own regulatory topic.
Who to Call Before Buying Land in Sullivan County
Zoning is set entirely by the specific one of Sullivan County's 15 towns, not the county. Direct WebFetch access to sullivanny.gov was not attempted in this research pass; confirm current department contacts directly.
Planning & Zoning
Sullivan County Division of Planning, Community Development and Environmental Management
Countywide planning coordination -- for the actual zoning ordinance, contact the specific town.
Septic / Onsite Wastewater
Sullivan County Public Health Services
Septic permitting under Appendix 75-A -- coordinate separately with NYC DEP if the parcel is within the regulated watershed boundary.
Other
NYC DEP Bureau of Water Supply
Whether a specific Sullivan County parcel is inside the regulated NYC watershed boundary, and DEP review requirements for septic or land-disturbing activity there.
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Get local guidanceTopics Specific to Sullivan County
Sources
- Sullivan County, New York — Wikipedia (accessed 2026-09)
- County Legislature | Sullivan County NY — Sullivan County, NY (accessed 2026-09)
- Neversink Reservoir — Wikipedia (accessed 2026-09)
- Rondout Reservoir — Wikipedia (accessed 2026-09)
- Extended NYC Watershed Land Acquisition Program — NYC Department of Environmental Protection (accessed 2026-09)
- Sullivan County casino looks to rebound — Spectrum Local News (accessed 2026-09)
- Sullivan County Bet on a Casino. Eight Years Later, It Just Borrowed $585 Million to Keep It. — Mid Hudson News (accessed 2026-09)
Last reviewed 2026-09