Grading & Drainage: Mount Vernon vs White Plains
How do grading & drainage rules compare between Mount Vernon, NY and White Plains, NY?
Mount Vernon and White Plains have similar restriction levels.
Mount Vernon, NY
Westchester County
Grading and drainage plans reviewed by the Building Department. Runoff cannot be directed onto adjoining property. Tight urban lots make drainage plans critical.
View full Mount Vernon rules →White Plains, NY
Westchester County
Grading permit required when excavating, filling, or regrading alters drainage on your property. Lots must drain toward streets or approved swales — not onto neighbors. Retaining walls over 4 ft require a building permit and engineered plans.
View full White Plains rules →Key Facts Comparison
| Fact | Mount Vernon | White Plains |
|---|---|---|
| Code | NYS RC R401.3 | - |
| Slope | 6 inches in 10 feet | - |
| Review | Building Department | - |
| Neighbor Runoff | Prohibited | - |
| Permit | - | Grading / building permit |
| Wall threshold | - | 4 ft engineered |
| Runoff | - | Cannot divert to neighbor |
| Impervious cap | - | Zone-specific (40-50%) |
Highlighted rows indicate differences between cities.
Mount Vernon FAQ
Can I drain my downspouts into my neighbor's yard?
No. Runoff must stay on your property or discharge to an approved public drain.
How much slope do I need around my foundation?
6 inches of fall within the first 10 feet per NYS Residential Code R401.3.
Does Mount Vernon review grading plans for rowhouses?
Yes. The Building Department requires a site grading plan showing finished grades and discharge points, especially on tight urban lots.
White Plains FAQ
Can I regrade my yard to raise it above my neighbor's?
Only if the new grade does not increase runoff onto adjacent properties. WP requires drainage be managed on your own lot or via approved piped outlets.
Do I need a permit for a retaining wall in White Plains?
Retaining walls over 4 feet require a building permit with engineered plans. Shorter walls may still need review if they affect drainage.
What is the impervious surface limit in White Plains residential zones?
Impervious surface caps typically range from 40-50% in residential districts, depending on the specific zone.
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