Emily Driehaus and Christina Liu |  Hydroviv Science Team   

Severe weather has been wreaking havoc on communities across the country, damaging critical infrastructure, even the quality of our water supply. Flooding and landslides from storms and recent atmospheric rivers have caused problems with drinking water infrastructure of both public and private water systems, contaminating water sources, leaving individuals without safe drinking water for days and sometimes weeks.

Drinking Water Contamination From Stormwater Runoff

Stormwater runoff can contaminate both groundwater and surface water during rainstorms, especially heavy precipitation events including hurricanes and atmospheric rivers. As stormwater runs into a storm drain or the nearest body of water, it picks up both biological and chemical contaminants from the ground that make their way into the water supply. Impervious surfaces exacerbate this problem, as stormwater cannot penetrate the ground and instead sits on top of these surfaces, contributing to flooding during a hurricane. Some local governments, such as Washington, D.C. and other municipalities surrounding the Chesapeake Bay, are working to combat this issue by replacing impervious surfaces with materials that soak up stormwater and allow it to permeate the ground instead of sitting on top of surfaces gathering contaminants that harm drinking water supply. 

Flooding and Water Systems

The influx of water from rain and flooding from severe storms can overwhelm both public and private water systems. Combined sewer overflows are systems designed to collect stormwater runoff, sewage, and other wastewater for transportation to a wastewater treatment plant. There the water is treated before moving on to a larger body. However, heavy rain and flooding can cause these systems to overflow, allowing untreated water to spill into nearby water sources, potentially contaminating drinking water supplies. This includes wells, which may also become contaminated with sewage, bacteria, and other microorganisms from stormwater runoff, flooding, or broken levees. 

Severe Storms and Water Treatment Facilities

Water treatment plants are not immune to the power outages and structural damage caused by high winds from severe storms. Treatment plants can lose power and the infrastructure can be damaged during these storms, leaving facilities without the ability to treat water. Equipment and infrastructure in water treatment plants can also be contaminated by runoff and floodwater. The inability of treatment plants to treat water due to power outages leads to boil water notices to ensure people in the affected area are not ingesting biological contaminants through their drinking water. 

Case Study: Hurricane Harvey

Hurricane Harvey made landfall in southeast Texas on August 25, 2017, and bombarded the Gulf Coast with heavy rain and wind for days. The Category 4 storm caused $125 million in damage in Texas and Louisiana, including damage to water systems. According to the Texas Commission on Environmental Quality, 61 public drinking water systems and 40 wastewater facilities were declared inoperable and 203 boil water notices were issued during the storm. Flooding also damaged chemical and energy plants in the area, leading to the contamination of surface water and drinking water reservoirs with sewage, wastewater and toxic chemicals. All inoperable facilities, except one wastewater facility, were restored in the cleanup process following the storm. However, tap water was not safe to drink in some communities for months, with boil water notices lasting into December for some areas affected by the storm.  

How To Prepare for Water Service Interruptions Ahead of a Severe Storm

The best way to avoid losing access to clean drinking water is to prepare before the storm arrives. While the links below focus on making preparations ahead of a hurricane, these are useful for anyone in the path of a severe storm that may cause flooding or interruptions in water service. 

The National Hurricane Survival Initiative recommends beginning preparations as far in advance as possible to avoid the chaos at stores right before the storm hits. Buying bottled water is an option for individuals preparing for a hurricane, but prices can increase dramatically right before a storm due to increased demand. Alternatively, individuals can store their own water in the days before a hurricane hits. The NHSI recommends storing water in containers made out of durable materials, such as plastic bottles. Because hurricanes can leave water treatment plants without power and contaminate water sources, individuals should prepare enough water, about a gallon, per person for at least three days.

The Centers for Disease Control also offers a detailed list of essential preparations to undertake before a storm, providing valuable guidance for severe weather and floods beyond hurricanes.

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