914 Basement Waterproofing and Repair in Larchmont & Mamaroneck, NY
Larchmont and Mamaroneck are old and flood-conscious: the typical Larchmont home was built around 1940 (90% before 1980) and the typical Mamaroneck village home around 1953. Mamaroneck publishes its own flood-preparedness handbook.
Basement contractors for Larchmont & Mamaroneck
How we pick: we list up to six companies per page. Independent firms come first, then firms based outside Westchester, then franchise or network affiliates. Companies that name the town as served come before those that serve the whole county. Listings are free, not paid, and not an endorsement. Home improvement license status was looked up in the Westchester County consumer license search on Oct 26 to 27, 2026, plumber license status in the county trade license search on Oct 27, 2026, and NYS mold license status in the state Labor Department data set; each profile shows what we found.
AMHAC (All Makes Heating & Air Conditioning)
No rating collected yetSump pump installation and repair; plumbing, heating and air conditioning
Avellino Construction
No rating collected yetBasement, foundation, chimney and exterior-wall waterproofing; masonry and roofing; 24-hour emergency service
Bombace Construction Co., Inc.
No rating collected yetYard drainage, curtain and French drains, dry wells, catch basins, sump pump installation, grading, retaining walls
De La Paz Masonry
No rating collected yetWaterproofing, French drains, sump pumps, masonry
F. La Rocca & Sons
No rating collected yetMasonry, drainage and waterproofing
Kellets Anchored Home Improvement
No rating collected yetExterior and interior waterproofing, drainage, crack repair, sump systems, foundation repair coordination
Services in Larchmont & Mamaroneck
Housing in Larchmont & Mamaroneck
| Place | Typical year built | Built before 1950 | Built before 1980 | Median home value |
|---|---|---|---|---|
| Larchmont | 1940 | 63.5% | 89.7% | $1,635,500 |
| Mamaroneck | 1953 | 44.2% | 78.4% | $717,200 |
Source: U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates (tables B25035, B25034, B25077), retrieved Oct 2026. Estimates carry a margin of error.
Flooding and water in Larchmont & Mamaroneck
- Westchester County’s Long Island Sound watershed program lists this municipality in the watershed study areas for “Blind, Beaver Swamp and Brentwood Brooks; Milton and Port Chester Harbors”, “Mamaroneck and Sheldrake Rivers; Mamaroneck Harbor”, “Pine and Stephenson Brooks; Larchmont Harbor”. [source]
- The Village of Mamaroneck describes itself as especially prone to flooding, sitting at the junction of the Mamaroneck River, the Sheldrake River, Beaver Swamp Brook, three watersheds, a 250-acre underground aquifer and Long Island Sound. [source]
- The state’s Mamaroneck River study found repeat flooding driven by undersized bridges and channels and tight development along the banks. [source]
- In Ida (September 2021), news reports described up to 14 feet of water in some Mamaroneck neighborhoods and basements filling to the first floor. [source]
Permit notes for Larchmont & Mamaroneck
From the municipality’s own pages, retrieved Oct 2026. Rules change, so call the building department before work starts.
- Larchmont: new sump pumps and drainage facilities need village permits; discharge should go to an owner-maintained dry well or detention basin. Discharging onto sidewalks or streets is not permitted and sump pumps may not connect to the sanitary sewer. [source]
- Mamaroneck: Local Law 2-2024 requires a plumber’s certification, by a plumber licensed to do business in Westchester County, covering sump pump discharge and sanitary sewer laterals. [source]
What basement work costs
| Job | Published range | Source |
|---|---|---|
| Typical interior drain system, 120 ft of wall (low / typical / high) | $3,041 / $7,095 / $12,163 | RenoVetted |
| Sump pump work, White Plains (low to high, midpoint about $1,574) | $840 to $3,673 | RenoVetted |
| Minor crack repairs and basic waterproofing, White Plains | $2,400 to $4,700 | HomeBlue |
| 8 piers or repair points, Yonkers (low / typical / high, modeled) | $4,223 / $10,136 / $16,893 | RenoVetted |
| Basement, partial (national) | $1,500 to $6,000 | HomeGuide |
| Per square foot, White Plains (low / typical / high, modeled) | $26 / $52 / $84 | RenoVetted |
| Whole-house filtration system, installed (national) | $850 to $5,400 | HomeGuide |
Most published Westchester figures are modeled estimates for White Plains or Yonkers, and national ranges where noted (water treatment figures are national). They are not bids for this town; Westchester quotes can run higher. See all costs and sources.
Homeowner guides
- Basement costs (2026)
- How to Check a Westchester Contractor's License Before You Sign
- Water in Basement After Heavy Rain
- Sump Pump Running Constantly
- Signs of a Wet Basement (and What Each One Means)
- Sump Pump vs. French Drain
- Mold in the Basement
- Fall Basement Prep Checklist for Westchester Homes
- Finishing a Basement in Westchester
- Private Well Water in Westchester
Nearby towns
Sources
- Westchester County Planning: Long Island Sound Watershed Program (watershed study areas by municipality)
- Village of Mamaroneck Building Department: Flood Preparedness Handbook
- NYS DEC / Village of Mamaroneck: Mamaroneck River Flood & Resiliency Study Report (2023)
- ABC7 New York: Ida damage, 14 feet of water in Mamaroneck (Sept. 2, 2021)
- Village of Larchmont Building Department: Sump Pumps
- Village of Mamaroneck: Local Law 2-2024 (plumber’s certification for sanitary sewer laterals)
- U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates, tables B25034, B25035, B25077 (via Census Reporter)
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