Inland Empire Weather: Long Dry Spells, Sudden Downpours
Riverside sits along the Santa Ana River at roughly 830 feet, framed by Mount Rubidoux, Box Springs Mountain and Evans Hill. It is one of the drier big cities in Southern California, averaging about 9.39 inches of precipitation a year on around 35 days, almost all of it between November and April. February is usually the wettest month.
Low totals do not mean low risk. Across the Inland Empire, rain on steep slopes and dry washes can turn into flash floods and debris flows with little warning. Hard, sun-baked ground sheds water fast, so a single strong storm can push runoff across yards, into garages and under doors.
For water damage in Riverside, whether it comes from a storm or a broken pipe, call (888) 817-5061. WaterQ connects you with a trusted, local restoration company.
The Santa Ana River and Riverside's Flood Defenses
Riverside was founded in 1870 beside a river that has a violent past. In the Great Flood of 1862, winter storms drove the Santa Ana River over its banks, flooding thousands of acres and killing 20 to 40 people. It flooded badly again in 1938.
Two large dams now help manage the river. Seven Oaks Dam, completed in 1999, captures runoff from Santa Ana Canyon before it reaches the Inland Empire. Prado Dam, built in 1941 downstream near Corona, holds floodwater from this region before it reaches Orange County. The Riverside County Flood Control and Water Conservation District runs local channels and basins and offers an online floodplain lookup.
The district takes non-emergency flooding reports at (951) 955-1200 during business hours and (951) 955-1230 after hours. In an emergency, call 911 first.
When Tropical Moisture Reaches Riverside County
Most of Riverside's rain comes from winter storms, but late-summer tropical moisture can arrive too. When Hilary moved through Southern California on August 20, 2023, it caused catastrophic flash flooding and debris flows in parts of the region. Damage in Riverside County reached about $126 million, including roughly $83 million to roads and bridges and $26 million to water systems, much of it in the Coachella Valley.
The lesson for city homeowners is to prepare for heavy rain outside the usual season. Clear gutters and yard drains, check that soil slopes away from the foundation and keep sandbags handy if your property sits at the bottom of a slope.
After a storm, storm damage cleanup may include tarping a roof, removing mud and silt, and drying soaked walls. Treat runoff that came in from outside as contaminated.
Owners, Renters and Property Managers
Riverside has about 100,000 housing units, and nearly half (45.8 percent) are renter-occupied. That means many water damage calls involve more than one party: a tenant who discovers the leak, a landlord or property manager who authorizes the work, and sometimes neighbors in adjoining units.
- Tenants: Report the leak to your landlord right away, in writing, and photograph the damage to your belongings for renters insurance.
- Landlords: Get access arranged quickly so drying can start, and keep moisture readings for your records.
- Businesses: Offices, warehouses and retail spaces may need drying scheduled around operating hours.
For city water service problems, such as a leak at the meter or in the street, contact Riverside Public Utilities. For damage inside the property, call (888) 817-5061 to be connected with a local provider.
A Practical Checklist for the First Hour
- Close the valve. Turn off the fixture supply or the main shutoff to stop the flow.
- Think about electricity. Stay out of water near outlets and appliances; switch breakers only if the panel area is dry.
- Classify the water. A clean supply line is Category 1. Sewage or outdoor runoff is Category 3 and needs protective gear and professional cleaning.
- Document before you clean. Photos and video of the source and damage help with any claim.
- Remove what you can. Move electronics, rugs, papers and small furniture to a dry area.
- Bring in help. Ask for water extraction as soon as possible to keep water from wicking into walls.
From Extraction to Final Repairs
The local restoration company will tailor the plan to your property, but water damage restoration in Riverside usually includes these stages.
Moisture mapping
Meters and infrared cameras show how far water has spread under flooring, into baseboards and inside walls.
Water removal and tear-out
Extractors remove standing water. Wet carpet pad, insulation and drywall that cannot be saved are cut out to open the structure.
Drying
Air movers and dehumidifiers run until readings reach dry goals. Riverside's dry air can help, but trapped moisture under flooring and in wall cavities still needs equipment. Read more on structural drying.
Restoration
Water damage repair puts back drywall, flooring and cabinets. It is wise to check a company's licensing, insurance and training (IICRC certification is one example) before work begins.
Mold Questions and Contractor Rules in California
The EPA says mold can begin growing on damp materials within 24 to 48 hours. Hidden leaks behind cabinets, under sinks and around water heaters are frequent culprits. Professional mold removal uses containment and air filtration so spores stay in the work area.
According to an industry roundup of state requirements, California does not appear to license mold assessors or remediators as such. The Toxic Mold Protection Act of 2001 had the state health department study mold standards, and no statewide licensing program for mold work was identified. If remediation involves construction, CSLB contractor rules still apply. Since January 1, 2025, a license is required for jobs of $1,000 or more in labor and materials, or for any job needing a permit.
On insurance: standard homeowners policies generally exclude flood, mudslide and debris flow, while NFIP flood policies cover mudflow and usually begin 30 days after purchase. Nearby Corona and Moreno Valley residents face similar questions.
Riverside Neighborhoods and Inland Empire Neighbors
WaterQ's free referral line connects callers across Riverside's neighborhoods and nearby Inland Empire cities with independent local restoration companies.
Neighborhoods
- Downtown
- Wood Streets
- Arlington
- Arlington Heights
- Arlanza
- La Sierra
- Canyon Crest
- Casa Blanca
- Magnolia Center
- Mission Grove
- Orangecrest
- Eastside
- Northside
- University
- Victoria
- Hawarden Hills
- Alessandro Heights
- Sycamore Canyon Springs
- Airport
- Ramona
Nearby communities
- Jurupa Valley
- Corona
- Norco
- Moreno Valley
- Colton
- Grand Terrace
- San Bernardino
- Eastvale
- Perris
Riverside Water Damage FAQ
How can I find out if my Riverside home is in a floodplain?
The Riverside County Flood Control and Water Conservation District offers an online Am I in a Floodplain map. FEMA flood zone status also affects flood insurance requirements and rates.
Who do I call about flooding from a street or flood channel in Riverside?
For emergencies, call 911. For non-emergency flooding, Riverside County Flood Control takes reports at (951) 955-1200 during business hours and (951) 955-1230 after hours. City service requests can go through Riverside 311.
Riverside is so dry. Do I really need flood insurance?
Riverside averages only about 9.39 inches of rain a year, but Inland Empire storms can cause flash floods and debris flows. Standard homeowners policies generally exclude flood, so consider a separate policy, keeping in mind the usual 30-day NFIP waiting period.
I rent my home. Who handles water damage?
Tell your landlord right away and document your belongings. The landlord usually arranges repairs to the building, while renters insurance may cover your personal property.
Is WaterQ the company that comes to my house?
No. WaterQ is a free referral service, available 24/7, that connects you with an independent local restoration company. That company inspects the damage and does the work.
Local emergency and flood resources
Official sources for alerts, flood maps and preparedness in and around Riverside: