A 34-to-0 vote and a seaplane base.
Wikipedia says residents voted 34 to 0 to incorporate in September 1930, when the village had 376 people, to keep home rule when Port Washington talked of becoming a city. In 1939–40 Pan Am's transatlantic Boeing 314 flying boats were based at Manorhaven's Toms Point on Manhasset Bay, and the town-owned Manorhaven Beach Park opened about 1936. The village sits on the Harbor Hill Moraine and covers 0.6 square miles, a quarter of it water.
The Census Bureau's latest five-year survey counts about 2,800 homes, with a median year built of 1967. 11% went up in the 1950s, 4% before 1940, and 34% after 1980. 25% are single-family detached houses, 36% are two-family, 11% are in buildings of five or more units, and 37% are owner-occupied.
So a typical house here has drain and water lines around 59 years old unless they've been replaced. Slow drains in several fixtures, a gurgling floor drain or rusty water from one tap are signs to have the main line and supply piping checked.
Gas piping.
The ACS shows 68% of homes heat with utility gas, 16% with electricity and only 10% with fuel oil. New gas ranges, dryers and water heaters need properly sized gas piping, and a leak test after any change; we do the gas line work.
On the sewer.
Nassau County's health department lists Manorhaven's sewers under the Village of Manorhaven (33 Manorhaven Blvd., 516-883-7000), and Wikipedia says the village system's sewage goes by contract to the Port Washington Water Pollution Control District for treatment. A backup that stops at your house is usually in your own line to the street; we clear it and repair or replace the line. If neighbors are backed up too, call the Village of Manorhaven at 516-883-7000.
Flood risk.
Laying FEMA's current flood map over the Census boundary, about 37% of Manorhaven is in the high-risk (1% annual chance) flood zone (25.0% in zone VE, 12.1% in zone AE; shares of the Census area, water included). On a sewered street, a backwater (sewer check) valve on your house sewer line can keep a street-sewer backup from coming in through basement floor drains. We install them. If your water heater or gas appliances ever sat in flood water, have them checked before relighting.
Water: Port Washington Water District.
EPA's service-area map puts essentially all residents on the Port Washington Water District; your bill is the final word. The main supplier's most recent 90th-percentile lead result was 2 ppb, under the 15 ppb action level; lead usually comes from a home's own pipes and fixtures, so results vary house to house. In EPA's UCMR 5 testing, the main supplier's highest single PFOA/PFOS result was 5.3 parts per trillion. EPA's 4 ppt limits apply as a running annual average starting in 2029, so one high sample is not a violation, but it's the kind of number a carbon filter is sized against. For a leak at the curb or in the street, call your water supplier. For anything on your side of the meter, call us.
Permits.
Manorhaven is an incorporated village, so plumbing permits go through the Village of Manorhaven's building department, not the town.