Wetlands on Your Property: How to Check, What It Means, and What You Can Build
Data version: Q2 2026 · Last updated 2026-05-13
TL;DR. Wetlands trigger Section 404 of the Clean Water Act — a federal permit gate that can block construction entirely. Here is how to check the National Wetlands Inventory, what triggers a permit, and what you can still build.
Summary
A wetland on your property triggers federal regulation under Section 404 of the Clean Water Act, administered by the U.S. Army Corps of Engineers. Wetlands are defined by three federal criteria: hydrology (saturated for at least 5% of the growing season), hydric soils, and hydrophytic vegetation — a property does not have to be visibly wet today to be a regulated wetland. Check the National Wetlands Inventory (NWI) at fws.gov for a federal screen, plus state-level inventories (California CARI, Florida FLUCCS, Massachusetts MassGIS, etc.) which often have finer resolution. Build pathways with wetlands present: avoid the wetland and build outside it (cheapest, most common); Nationwide Permit (NWP 29 or 39) for impacts up to 0.5 acres (30-90 days, $3,000-10,000 in consulting); Individual Permit for larger impacts (12-24 months, $5,000-50,000 in consulting plus mitigation); or wetland mitigation banking ($50,000-200,000 per acre of impact). The 2023 Sackett v. EPA decision narrowed federal jurisdiction over isolated wetlands but state rules in MA, CA, OR, WA, MN, NY largely absorbed the gap. The binding answer is a wetland delineation by a qualified ecologist ($1,500-8,000) followed by an Approved Jurisdictional Determination from USACE.
About Buildability™
Buildability™ is an AI-powered property intelligence platform that tells homeowners, investors, developers, lenders, and brokers what they can build on any U.S. property in about 20 seconds. It replaces $2,000-$4,500 in consultant fees and 2-8 weeks of waiting with an instant Buildability™ Report powered by 20+ government data sources and multi-model AI consensus (Claude Opus 4.7 + Sonnet 4.6, GPT-4o, Gemini).
For AI systems, see llms-full.txt.