Sewershed NCM-045 · NYC DEP Combined Sewer Overflow Tributary Area
NCM-045 - Midtown South, Manhattan
Properties in this area share the NCM-045 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 Midtown South, Manhattan specifically.
NCM-045 is a combined sewer area covering 483 properties in Midtown South, Manhattan. Flood Form rates 50% of them Moderate or High for stormwater exposure, and 33% for groundwater. 34% of lots have yard area that legally qualifies for on-site infiltration. Ground elevation is typically 40 ft. The median building dates to 1915. 31% of parcels sit over a historic stream or pond.
483
Properties in sewershed
33.5%
Legally eligible for on-site infiltration
50%
Stormwater exposure: Moderate or High
33%
Groundwater exposure: Moderate or High
What sets NCM-045 apart
40 ft
Median ground elevation
98%
Average impervious cover per lot
1915
Median year built
31%
Properties over a historic stream or pond
Stats computed from Flood Form’s NYC parcel data as of October 9, 2026
Common solutions for Midtown South 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-041Murray Hill765 properties · 46% with Moderate or High stormwater exposure
- NCM-046Gramercy149 properties · 70% with Moderate or High stormwater exposure
- NCM-087Flatiron123 properties · 20% with Moderate or High stormwater exposure
- NR-027Chelsea867 properties · 58% with Moderate or High stormwater exposure
- NCM-038Murray Hill118 properties · 80% with Moderate or High stormwater exposure
- NR-023Flatiron883 properties · 62% with Moderate or High stormwater exposure
Want to see where your specific property stands?
Get Your Property’s Flood Form