Sewershed HP-033 · NYC DEP Combined Sewer Overflow Tributary Area
HP-033 - Westchester Square, Bronx
Properties in this area share the HP-033 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 Westchester Square, Bronx specifically.
HP-033 is a combined sewer area covering 3,450 properties in Westchester Square, Bronx. Flood Form rates 52% of them Moderate or High for stormwater exposure, and 7% for groundwater. 80% of lots have yard area that legally qualifies for on-site infiltration. Ground elevation is typically 38 ft. The median building dates to 1927. 10% of parcels sit over a historic stream or pond. According to NYC DEP green infrastructure records, this sewershed drains to Westchester Creek. NYC DEP has built 40 green infrastructure assets here.
3,450
Properties in sewershed
80.1%
Legally eligible for on-site infiltration
52%
Stormwater exposure: Moderate or High
7%
Groundwater exposure: Moderate or High
What sets HP-033 apart
38 ft
Median ground elevation
83%
Average impervious cover per lot
1927
Median year built
10%
Properties over a historic stream or pond
Stats computed from Flood Form’s NYC parcel data as of October 9, 2026
Common solutions for Westchester Square 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-015Pelham Bay1,919 properties · 42% with Moderate or High stormwater exposure
- HP-012Unionport745 properties · 18% with Moderate or High stormwater exposure
- HP-013Unionport4,602 properties · 33% with Moderate or High stormwater exposure
- HP-009Soundview1,644 properties · 50% with Moderate or High stormwater exposure
- HP-016Schuylerville1,359 properties · 50% with Moderate or High stormwater exposure
- HP-026Schuylerville5,449 properties · 47% with Moderate or High stormwater exposure
Want to see where your specific property stands?
Get Your Property’s Flood Form