Why Modesto Streets Fill Up in Winter
Modesto averages about 13.11 inches of precipitation a year, most of it in winter and much of it delivered by atmospheric rivers or bomb cyclones. When those storms hit, a local quirk becomes obvious: the city does not have a full storm sewer system, and many streets flood during winter rains.
Ponded water in the street is usually just an inconvenience. It becomes a property problem when it pushes up a driveway into a garage, seeps under a door at a low entry or soaks a crawlspace. Passing cars can send waves toward homes on flooded blocks.
Simple steps help. Keep gutters, downspouts and the curb in front of your home clear of leaves, and make sure soil slopes away from the foundation. If water does get in, flood cleanup in Modesto should start quickly, before carpet pad and drywall wick it higher.
The Tuolumne River and Don Pedro Spills
The Tuolumne River runs along Modesto, and Dry Creek joins it in the area. Upstream, Don Pedro Dam stores water for the region, but only 340,000 acre-feet of its reservoir is designated for flood control. That is a relatively small amount for a California reservoir, so Don Pedro frequently fills and spills in winter storms, causing damage downstream.
The 1997 New Year's Flood showed what that can mean. Inflows to Don Pedro reached 120,000 cubic feet per second, the largest since 1862. Releases peaked at 60,000 cubic feet per second, about six times the river channel's capacity, and caused extensive property damage along the river.
If you live or own property near the river or Dry Creek, find out your flood zone and consider flood coverage. Standard homeowners policies generally exclude flood, and a new NFIP policy usually takes about 30 days to begin.
Priorities in the First Hours
- Shut off water at the fixture or the main if the source is indoors.
- Stay clear of electrical hazards and never wade near outlets, cords or appliances.
- Treat street and river water as contaminated. It is Category 3 water and can carry sewage, oil and debris.
- Take photos and video before you move or throw anything away.
- Move valuables to a dry area and prop furniture up if you can do it safely.
- Contact your insurer and, if you rent, your landlord. About 44 percent of Modesto's homes are renter-occupied, so both parties often need to be involved.
For emergency water removal, call any time, day or night.
The Restoration Sequence for Stanislaus County Homes
Water damage restoration in Modesto generally follows a clear sequence:
Inspection
The restoration company identifies the source, classifies the water and maps moisture with meters and infrared cameras, including under raised floors and in crawlspaces.
Removal
Standing water is extracted. Wet carpet pad, insulation and drywall that cannot be saved are removed, especially after outdoor floodwater.
Drying and sanitizing
Affected areas are cleaned, then dehumidifiers and air movers run until readings meet dry standards. More on structural drying.
Rebuild
Flooring, drywall, paint and cabinetry are restored once drying is confirmed. See water damage repair. Ask any company you consider about its licensing, insurance and IICRC or similar training.
Storm Damage Cleanup After Atmospheric Rivers
Modesto's wettest season on record brought 26.01 inches of rain between July 1982 and June 1983, about double a normal year. Seasons like that, or a few back-to-back storms, can find every weak spot in a roof, gutter and window seal.
Storm damage cleanup in Modesto may involve tarping a damaged roof, drying an attic, pulling wet insulation and cleaning up water that entered through a garage. Read more about storm damage cleanup and flood cleanup. Report street flooding or a clogged drain to the City through GoModesto.
Mold, Crawlspaces and California Licensing
Mold can start on wet materials within 24 to 48 hours, according to EPA guidance. Crawlspaces under older homes and wall cavities behind leaks are common places for it to take hold out of sight.
An industry roundup of state requirements says California does not have a state license specifically for mold assessors or remediators. The Toxic Mold Protection Act of 2001 directed the state health department to study the issue and develop mold standards, but no statewide mold licensing program was found. Mold removal in Modesto that involves construction is still covered by Contractors State License Board rules.
Since January 1, 2025, CSLB requires a license for any job of $1,000 or more in labor and materials, or any job needing a permit. Look up a contractor's license, bonding and workers' comp with the CSLB lookup, and read about mold cleanup.
Help for Businesses and Property Managers
Commercial buildings, apartment complexes and retail spaces need the same careful drying, often on a tighter schedule. A single plumbing failure can affect several units or tenants, so early moisture mapping and clear documentation matter.
Call (888) 817-5061 to be connected with a local restoration provider for commercial or multi-unit work. Owners with property up and down Highway 99 can also visit our Stockton and Fresno pages.
Areas In and Around Modesto
WaterQ's free referral line connects callers in Modesto, its surrounding unincorporated neighborhoods and nearby Stanislaus County towns with independent local restoration companies.
Neighborhoods
- Downtown
- Graceada Park
- West Modesto
- Airport
- Bret Harte
- Bystrom
- Parklawn
Nearby communities
- Ceres
- Riverbank
- Salida
- Empire
- Turlock
- Oakdale
- Hughson
- Waterford
- Del Rio
- Keyes
- Patterson
Modesto Water Damage FAQ
Why do so many Modesto streets flood when it rains?
Modesto does not have a full storm sewer system, so many streets flood during winter storms. Keeping curbs and drains clear of leaves helps, and you can report problems through GoModesto.
Can the Tuolumne River still flood Modesto?
Yes. Don Pedro Dam has relatively little flood-control space and frequently fills and spills in winter storms. In the 1997 flood, releases reached about six times the channel's capacity and caused extensive damage along the river.
Does homeowners insurance cover street flooding that enters my garage?
Flood damage from outside water is generally excluded from standard homeowners policies. It is typically covered by an NFIP or private flood policy, which usually has a 30-day waiting period for new policies.
How can I tell if a Modesto restoration contractor is licensed?
Use the CSLB Check a License tool. Since January 1, 2025, California requires a CSLB license for jobs of $1,000 or more in labor and materials or any job that needs a permit.
Is WaterQ the company that dries my house?
No. WaterQ is a free referral service, available 24/7, that connects you with an independent local restoration company. That company performs the inspection, drying and repairs.
Local emergency and flood resources
Official sources for alerts, flood maps and preparedness in and around Modesto: