Yes, it is legal to collect rainwater in New York. No state law prohibits residential rainwater harvesting, and the state generally treats it as a benefit for stormwater management. What the state does regulate is how a collection system is built once you connect it to your home’s plumbing, and a few municipalities layer their own rules on top.
Why Rainwater Collection Is Legal in New York
New York follows the riparian doctrine, which gives landowners the right to make reasonable use of water on or adjacent to their property. That includes rain that falls on your roof and yard. Some western states cap collection volumes under prior appropriation water-rights systems; New York does not. As long as your use does not unreasonably interfere with a neighbor’s water access, you are within your rights.
The rules that actually govern rainwater systems live in the building code, not water law. Chapter 13 of the New York State Plumbing Code covers nonpotable water systems, including rainwater collection and distribution.1UpCodes. Plumbing Code of New York State – Chapter 13 Nonpotable Water Systems Those provisions do not decide whether you may collect rainwater. They decide how a system must be engineered if it feeds indoor fixtures.
When You Need a Permit
A basic rain barrel sitting under a downspout and feeding a garden hose generally does not require a permit. The moment you modify your home’s plumbing to pipe a cistern into indoor fixtures, that changes. New York State requires a building permit for the installation or modification of plumbing systems.2New York State Department of State. Building Permit Application Permit fees for residential plumbing modifications typically run from about $25 to $400 depending on the municipality.
Confirm with your local building department before starting work. Municipal codes can add requirements the state code does not, such as restrictions on where a cistern can sit, how tall it can be, or whether it needs to be screened from view.
What the Plumbing Code Requires for Connected Systems
If your system connects to indoor plumbing, the code sets specific engineering standards to protect water quality and prevent contamination of the public supply.
Debris Excluders and First-Flush Diverters
Every downspout feeding a storage tank must connect to a debris excluder that keeps leaves and sticks out of the tank. The code also requires an automatic first-flush diverter, which routes the initial surge of each storm away from storage because that first wave carries the grime that has built up on your roof. The diverter has to operate automatically, without manual valves.1UpCodes. Plumbing Code of New York State – Chapter 13 Nonpotable Water Systems
Storage Tanks
Tanks must be built from durable, nonabsorbent, corrosion-resistant materials. Above-ground tanks need protection from direct sunlight through opaque UV-resistant materials, a sun barrier, or placement inside a garage, crawl space, or shed, because algae growth accelerates in sunlight.1UpCodes. Plumbing Code of New York State – Chapter 13 Nonpotable Water Systems
Overflow
Every tank needs an overflow pipe sized to handle a full tank. The pipe must be protected from insects and vermin, cannot have a shutoff valve, and must discharge away from the tank foundation and adjacent properties. A backwater valve is required on each overflow and tank drain pipe.3ICC Digital Codes. New York City Plumbing Code 2022 – Chapter 13 Nonpotable Water Systems
Backflow Prevention and Cross-Connections
This is the strictest part of the code. If your home also connects to a public water supply, you must prevent any possibility of untreated rainwater flowing backward into the municipal lines. The state Plumbing Code requires backflow prevention in accordance with the Department of Health Sanitary Code, and cross-connections between a private supply and the public potable supply are prohibited without an approved cross-connection control device.4UpCodes. New York State Plumbing Code 2020 – Chapter 6 Water Supply and Distribution
Any nonpotable distribution piping inside the home must be purple and marked “CAUTION: NONPOTABLE WATER — DO NOT DRINK” at intervals of no more than 25 feet and at every point where piping passes through a wall, floor, or roof. The marking must show direction of flow.4UpCodes. New York State Plumbing Code 2020 – Chapter 6 Water Supply and Distribution
What You Can Use the Water For
Untreated rainwater is fine for outdoor irrigation, washing vehicles and equipment, and similar non-potable tasks. If your plumbing meets code, you can also use it to flush toilets and supply trap primers indoors.5ICC Digital Codes. 2020 Residential Code of New York State – P2901.1 Potable Water
Drinking untreated rainwater is another matter. Rain picks up bacteria from bird droppings, airborne pollutants, and residue from your roof, and roofing materials themselves can leach copper, aluminum, and lead. If you plan to drink harvested water or use it on crops eaten raw, UV sterilization will kill bacteria, pathogens, and viruses. The CDC recommends regularly testing harvested rainwater for harmful germs and chemicals and properly maintaining any collection system used in or around the home.6CDC. Preventing Drinking Water-Related Illnesses
Extra Rules in New York City
New York City runs its own plumbing code. Inside the five boroughs, Section PC 1303 governs rainwater collection.7New York City Administrative Code. New York City Plumbing Code – Section PC 1303 Nonpotable Rainwater Collection and Conveyance Systems
Collection surfaces are limited to above-ground impervious roofing built from approved materials. You cannot collect water from parking areas or pedestrian walkways unless the water is used only for landscape irrigation. Rooftop equipment such as cooling towers, evaporative coolers, and solar water heaters cannot discharge onto any surface feeding your collection system.8UpCodes. New York City Plumbing Code 2022 – Chapter 13 Nonpotable Water Systems
The city also requires a roof washer that diverts the first portion of each rainfall, with a field-adjustable diverted volume and automatic operation. Debris excluders must be self-cleaning, which is stricter than the state’s general debris-excluder rule. Gutters and downspouts must slope at least 1/8 inch per foot along their entire length, with watertight joints.8UpCodes. New York City Plumbing Code 2022 – Chapter 13 Nonpotable Water Systems
HOAs and Local Restrictions
New York has no statute protecting a homeowner’s right to collect rainwater against a homeowner’s association. Some other states have passed such laws; New York has not. An HOA could restrict visible rain barrels or dictate where they sit based on aesthetic guidelines. Read the bylaws before you buy equipment.
Costs and Rebate Programs
A standard 50-to-60 gallon rain barrel runs roughly $30 to $240 depending on material and features. Larger cistern systems with pumps typically cost $2,000 to $12,000 installed professionally, depending on tank size, burial depth, and the complexity of the indoor connections.
Some municipalities offset these costs. Erie County, in partnership with the Western New York Stormwater Coalition, offers rain barrels at 50% to 75% off typical pricing to households in participating municipalities.9Erie County. Erie County Partners Offering Rain Barrels and Compost Bins New York City ran a free rain barrel giveaway for over a decade but discontinued it in 2025, shifting to flood prevention kits that include sensors, barriers, and sump pumps; the Department of Environmental Protection has indicated plans to offer tutorials on building your own barrel. Check with your local environmental or public works department to see whether your municipality runs a program of its own.