Sewershed HP-025 · NYC DEP Combined Sewer Overflow Tributary Area
HP-025 - Longwood, Bronx
Properties in this area share the HP-025 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 Longwood, Bronx specifically.
HP-025 is a combined sewer area covering 3,526 properties in Longwood, Bronx. Flood Form rates 37% of them Moderate or High for stormwater exposure, and 29% for groundwater. 75% of lots have yard area that legally qualifies for on-site infiltration. Ground elevation is typically 58 ft. The median building dates to 1964. 28% of parcels sit over a historic stream or pond. According to NYC DEP green infrastructure records, this sewershed drains to East River / Open Waters. NYC DEP has built 11 green infrastructure assets here.
3,526
Properties in sewershed
75%
Legally eligible for on-site infiltration
37%
Stormwater exposure: Moderate or High
29%
Groundwater exposure: Moderate or High
What sets HP-025 apart
58 ft
Median ground elevation
83%
Average impervious cover per lot
1964
Median year built
28%
Properties over a historic stream or pond
Stats computed from Flood Form’s NYC parcel data as of October 9, 2026
Common solutions for Longwood 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
- HP-003Crotona Park East1,661 properties · 34% with Moderate or High stormwater exposure
- HP-002Hunts Point824 properties · 42% with Moderate or High stormwater exposure
- WI-072Melrose583 properties · 37% with Moderate or High stormwater exposure
- HP-008Soundview1,033 properties · 47% with Moderate or High stormwater exposure
- WI-075Concourse Village778 properties · 39% with Moderate or High stormwater exposure
- WI-068Mott Haven8,315 properties · 34% with Moderate or High stormwater exposure
Want to see where your specific property stands?
Get Your Property’s Flood Form