How to Turn Off Utilities Before a Flood

Floodwater and live utilities are a fatal combination. Electricity in contact with water kills within milliseconds. Gas leaks in flooded structures trigger explosions. Yet most homeowners have never located their utility shutoffs — and many don't know that turning them off at the right moment is the single most effective action you can take before floodwater arrives.

This guide gives you the exact sequence, the specific locations, and the tools required to shut down electricity, natural gas, and water at your home before a flood event. Read it now. Practice it before you need it.

Why You Must Act Before Water Arrives

Floodwater that contacts a live electrical system can energize the entire water column — including the street, neighboring basements, and anything submerged nearby. The U.S. Consumer Product Safety Commission reports that electrocution in flooded conditions accounts for dozens of deaths after major flood events, with many occurring after the immediate flood threat has passed.

The critical rule: never enter flooded areas to turn off utilities. If your basement is already underwater, do not go down there to reach the electrical panel. Turn off utilities BEFORE water enters your home. This requires advance preparation and a clear action plan.

Use our Flood Emergency Action Plan to understand the full sequence of pre-flood actions. Utility shutoff is one of the most time-sensitive steps — along with moving valuables to upper floors and deploying flood barriers.

How to Turn Off Electricity Before a Flood

Find Your Electrical Panel

Your main electrical panel (breaker box or fuse box) controls all electrical circuits in your home. Common locations:

Basement or utility room — most common in older homes
Garage — common in newer construction
Hallway or closet — particularly in condos and apartments
Exterior wall — some older homes have outdoor panels

If your panel is in the basement, this creates a critical problem: once floodwater enters the basement, the panel becomes inaccessible. If your panel is in a flood-vulnerable location, have a licensed electrician relocate it above the expected flood line — ideally 12 inches above your Base Flood Elevation (BFE). FEMA documents this as a recommended mitigation measure that also qualifies for flood insurance premium reductions.

Step-by-Step Electrical Shutoff

Open the main electrical panel door — usually a metal door on a gray or beige box.
Locate the main breaker — this is the large double-pole breaker at the top or bottom of the panel, typically labeled "MAIN." It controls all circuits simultaneously.
Flip the main breaker to OFF — move it to the OFF position. On most panels, this means pushing it away from the center (toward the outer edge).
Verify power is off — check a nearby outlet or light switch to confirm no power.

If you cannot safely reach the panel (water is already in the room), call your utility company's emergency line. They can shut off power at the meter from outside your home. Do not attempt to reach a submerged panel under any circumstances.

Note on generators: If you're using a portable generator, keep it at least 20 feet from your home and never connect it directly to household wiring without a transfer switch. Generator exhaust is also a serious carbon monoxide hazard — never operate generators indoors.

Tools to Keep Near Your Panel

Rubber-soled shoes (always wear when working near electrical equipment)
Non-contact voltage tester to confirm power is off before touching anything
Waterproof flashlight — panel rooms are often dark; having a reliable light source is essential during an emergency. Consider the Streamlight or Coast brand waterproof flashlights rated IPX7 or higher.

How to Turn Off Natural Gas Before a Flood

Gas leaks are more dangerous in flood conditions because floodwater can damage gas line connections, move structures slightly to stress fittings, and carry ignition sources. A gas leak in a flooded or recently-flooded structure can result in an explosion hours or days after the flood — even after you've returned home.

Locate Your Gas Shutoff Valve

Your main gas shutoff valve is located on the gas supply line just before it enters your home — typically on the outside of the house near the gas meter. The meter itself is usually located:

On the exterior of the home (most common)
In a utility alcove or mechanical room
Sometimes in the basement on the incoming gas line

The shutoff valve is a small lever or rectangular nub on the gas pipe. When the lever is parallel to the pipe, gas flows. When it is perpendicular (90 degrees) to the pipe, gas is off.

Step-by-Step Gas Shutoff

Locate the shutoff valve on the gas meter or incoming supply line.
Use a gas shutoff wrench or adjustable wrench — the valve requires a firm quarter-turn. Keep a dedicated gas shutoff tool with your emergency supplies. The Klein Tools or Channellock gas shutoff wrenches are compact and designed for this exact application.
Turn the valve 90 degrees until it is perpendicular to the pipe.
Do NOT turn the gas back on yourself. After shutting off gas for a flood, the utility company must inspect and restore service. Gas appliances need to be re-lit by a qualified technician.

Important: Only shut off gas if you smell gas, hear a hissing sound, or if flooding is imminent. If you've already shut off gas and don't smell gas after the flood, you can leave it off but do not attempt to restore it yourself.

Individual Appliance Shutoffs

Every gas appliance (water heater, furnace, range, dryer) has its own shutoff valve — typically a small ball valve or lever on the gas supply line near the appliance. If your main gas shutoff is in an inaccessible location, these individual valves provide a backup option. Label them with permanent marker during your pre-flood preparation.

How to Turn Off Water Before a Flood

Shutting off water before a flood prevents contaminated floodwater from backflowing into your home's water system — a phenomenon called "cross-contamination" that can render your entire plumbing system unsafe long after the flood recedes.

Main Water Shutoff Locations

There are typically two locations to shut off water:

Main shutoff valve inside the home — usually located where the main water line enters the home (basement, crawlspace, utility room, or under a kitchen sink). This is typically a gate valve (round wheel you turn) or ball valve (lever).
Street shutoff (curb stop) — located at the property line, often in a small underground vault or box with a metal cover. This requires a specialized curb stop key to operate and is typically operated by the water utility.

Step-by-Step Water Shutoff

Turn the main indoor shutoff valve clockwise until fully closed (for a gate valve) or turn 90 degrees perpendicular to the pipe (for a ball valve).
Turn on a faucet to release pressure — this confirms the shutoff worked and relieves residual pressure in the pipes.
If your indoor shutoff is inaccessible, contact your water utility to shut off at the curb stop.

A properly placed main water shutoff should be one of the first items in your home inspection checklist. Use our Home Flood Vulnerability Inspection Guide to audit your utility shutoff locations and accessibility.

Create Your Utility Shutoff Map

The single most important pre-flood preparation for utilities is documentation. Create a simple map of your home showing:

Location of main electrical panel
Location of main gas shutoff valve
Location of main water shutoff valve
Location of individual appliance shutoffs (furnace, water heater)
What tools are needed for each (gas wrench, flashlight)
Utility company emergency numbers

Store this map in a waterproof document bag in your emergency kit. Include it in your Family Flood Evacuation Plan so every adult in your household knows where to go and what to do.

When to Shut Off Utilities

Alert Level	Action
Flood Watch	Locate shutoffs, gather tools, review plan
Flood Warning	Shut off gas and consider electricity if evacuation ordered
Evacuation Order	Shut off all utilities before leaving
Water entering home	Evacuate immediately — do not attempt to reach submerged utilities

Never wait until water is entering your home to shut off utilities. The safe action window closes quickly. Build shutoff into your go-bag checklist so it becomes automatic. See our complete Flood Emergency Kit Checklist for all pre-flood preparation steps.

After the Flood: Restoring Utilities Safely

Restoring utilities after a flood is as important — and as dangerous — as shutting them off. Follow these rules:

Never restore electricity until a licensed electrician inspects the panel and all wiring for water damage and short circuits
Never restore gas until the utility company inspects and re-lights appliances
Water can usually be restored once local authorities confirm the municipal water supply is safe
Have your HVAC system inspected for flood damage before operating it
Replace GFCI outlets in any area that was flooded — they cannot be trusted after submersion

The cost of professional utility inspection after a flood ($200–500) is trivial compared to the risk of electrocution, gas explosion, or carbon monoxide poisoning from damaged systems. Budget for it as part of your flood recovery plan.