The creek
Longmont's defining property risk is St. Vrain Creek. The creek drains a steep mountain watershed above Lyons and runs directly through the middle of the city, and in September 2013 it delivered a flood that split Longmont in half, destroyed homes on both banks, and took out bridges and infrastructure across the corridor. Left Hand Creek added to it from the west.
Everything about local flood risk since then has been shaped by that event. The Resilient St. Vrain Project — widening the channel, rebuilding bridges and increasing conveyance capacity through town — has been running in phases for years, and as segments complete, effective floodplain mapping for some properties changes with them.
If you own property anywhere near the corridor, two things are worth doing. Check the current mapping rather than what you were told at closing. And understand that a standard homeowners policy does not cover flood — that requires a separate NFIP or private flood policy, with a waiting period before it takes effect.
The housing
Old Town Longmont carries a substantial stock of pre-1940 homes. Clay sewer laterals under mature street trees, some remaining original supply plumbing, and basements finished decades after construction. Winter pipe bursts and sewer backups both concentrate here.
Post-war and 1960s to 1980s subdivisions ring the core, with copper supply plumbing and full finished basements — the standard Front Range profile where appliance and water heater failures dominate.
Newer southeast and southwest development is 1990s and later with modern plumbing, where the water losses are almost entirely appliances, water heaters and sump pump failures during monsoon storms.
Services
Longmont water damage restoration is the main service, with ZIP coverage listed separately. Also: flood cleanup, storm and flood cleanup, fire and smoke damage, mold remediation, sewage cleanup and structural drying.
Cost
Longmont runs at Front Range rates, typically $1,500 to $8,000, with properties in the historic flood corridor carrying additional risk and, in some cases, additional cost when a rebuild has to account for flood-resistant construction. The comparison table is in the cost guide.
Nearby coverage: Boulder, Fort Collins, Greeley and the full service area.
Frequently asked questions
How badly did 2013 affect Longmont?
Severely. The St. Vrain Creek and Left Hand Creek both went far out of bank in September 2013, cutting the city in two and flooding neighborhoods on both sides. The Resilient St. Vrain Project, the multi-year channel and bridge program that followed, exists specifically to increase the creek's capacity through town.
Am I still in a flood zone after the channel work?
Possibly not, and that is worth checking. The Resilient St. Vrain work has changed effective floodplain mapping for some properties as segments have been completed. Check current FEMA mapping and the city's own information rather than relying on what you were told at purchase.
Does flood insurance cover creek flooding?
Only a flood policy does. Standard homeowners policies exclude water arriving from the ground surface, which is what creek overtopping is. NFIP policies typically carry a 30-day waiting period, so buying one when the forecast turns does not help that season.
What about the older Old Town housing?
Old Town Longmont has a significant stock of pre-1940 homes with the plumbing to match — clay sewer laterals, some remaining galvanized supply, and basements that were finished long after they were built. Winter pipe failures and sewer backups both concentrate there.