Sewershed HP-023 · NYC DEP Combined Sewer Overflow Tributary Area
HP-023 - Eastchester, Bronx
Properties in this area share the HP-023 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 Eastchester, Bronx specifically.
HP-023 is a combined sewer area covering 396 properties in Eastchester, Bronx. Flood Form rates 51% of them Moderate or High for stormwater exposure, and 27% for groundwater. 62% of lots have yard area that legally qualifies for on-site infiltration. Ground elevation is typically 32 ft. The median building dates to 1985. 25% of parcels sit over a historic stream or pond. According to NYC DEP green infrastructure records, this sewershed drains to Hutchinson River. NYC DEP has built 12 green infrastructure assets here.
396
Properties in sewershed
62.4%
Legally eligible for on-site infiltration
51%
Stormwater exposure: Moderate or High
27%
Groundwater exposure: Moderate or High
What sets HP-023 apart
32 ft
Median ground elevation
76%
Average impervious cover per lot
1985
Median year built
25%
Properties over a historic stream or pond
Stats computed from Flood Form’s NYC parcel data as of October 9, 2026
Common solutions for Eastchester 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-031Edenwald481 properties · 7% with Moderate or High stormwater exposure
- HP-024Wakefield7,565 properties · 41% with Moderate or High stormwater exposure
- HP-014Williamsbridge14,618 properties · 32% with Moderate or High stormwater exposure
- HP-007Woodlawn8,916 properties · 42% with Moderate or High stormwater exposure
- HP-015Pelham Bay1,919 properties · 42% with Moderate or High stormwater exposure
- HP-033Westchester Square3,450 properties · 52% with Moderate or High stormwater exposure
Want to see where your specific property stands?
Get Your Property’s Flood Form