Willis, TX Building Setbacks & Zoning: Lot Coverage Limits (2026)

Texas counties lack zoning authority to impose lot coverage limits — Montgomery County does not regulate impervious surface percentages on unincorporated parcels. However, Montgomery County Engineer's Office and Drainage District rules require stormwater management for new development under the county Flood Damage Prevention Order, adopted to participate in the FEMA National Flood Insurance Program following Hurricane Harvey 2017 catastrophic flooding along the San Jacinto River and Lake Conroe. Conroe zoning Code Ch. 90 sets district-specific maximum lot coverage — typical SF-1: 40%, SF-2: 50%, commercial up to 70-80% with stormwater detention. The Woodlands Development Standards Committee enforces covenant-based coverage limits including impervious surface, pool, and patio coverage by village — Alden Bridge and Cochran's Crossing have stricter limits to preserve tree canopy. TX Water Code Ch. 16 governs floodplain; FEMA FIRM maps apply to Lake Conroe shoreline, Spring Creek, Peach Creek, and West Fork San Jacinto.