Sewershed NCM-050 · NYC DEP Combined Sewer Overflow Tributary Area
NCM-050 - Chinatown, Manhattan
Properties in this area share the NCM-050 combined sewer — during moderate-to-heavy rain, runoff can exceed pipe capacity faster than it drains, which is what drives sewer backup exposure block by block. Here’s what that looks like for Chinatown, Manhattan specifically.
NCM-050 is a combined sewer area covering 1,193 properties in Chinatown, Manhattan. Flood Form rates 46% of them Moderate or High for stormwater exposure, and 9% for groundwater. 23% of lots have yard area that legally qualifies for on-site infiltration. Ground elevation is typically 36 ft. The median building dates to 1910. 18% of parcels sit over a historic stream or pond.
1,193
Properties in sewershed
23.4%
Legally eligible for on-site infiltration
46%
Stormwater exposure: Moderate or High
9%
Groundwater exposure: Moderate or High
What sets NCM-050 apart
36 ft
Median ground elevation
98%
Average impervious cover per lot
1910
Median year built
18%
Properties over a historic stream or pond
Stats computed from Flood Form’s NYC parcel data as of October 9, 2026
Common solutions for Chinatown properties
Downspout Diversion
Redirects roof runoff away from the combined sewer and into landscaped or permeable areas on the lot.
Infiltration System
Drywells or infiltration chambers that let stormwater soak into the ground on-site instead of entering the sewer.
Detention System
Holds stormwater temporarily and releases it slowly, reducing peak flow into the combined sewer during a storm.
Drain Improvement
Upgrades yard, area, or foundation drains so water is carried away from the building instead of pooling.
Foundation Waterproofing
Protects the foundation from groundwater intrusion, relevant where groundwater exposure runs high.
Nearby sewersheds
- NCM-063Two Bridges446 properties · 45% with Moderate or High stormwater exposure
- NCM-042Lower East Side154 properties · 47% with Moderate or High stormwater exposure
- NCM-028Lower East Side263 properties · 51% with Moderate or High stormwater exposure
- NCM-075SoHo1,185 properties · 63% with Moderate or High stormwater exposure
- NCM-057Lower East Side158 properties · 50% with Moderate or High stormwater exposure
- NCM-073Tribeca441 properties · 54% with Moderate or High stormwater exposure
Want to see where your specific property stands?
Get Your Property’s Flood Form