Wind and Riverine Flooding
Riverine flooding can be a result of storm surge from hurricanes, winter
storms, or excessive rainfall overflowing river and stream banks.
The Blackstone River basin, which encompasses nine communities in
Rhode Island and several more in southwestern Massachusetts, has
experienced flooding many times, with records dating back as far
as 1818. When land in a floodplain is developed, cyclical floods
can become costly and dangerous.
Update: In October 2005, a record 15.38 inches of rain fell
in the Blackstone Valley area, much of it over a nine-day period.
Stormwater overpowered Woonsocket's waterwater treatment facility
and caused it to discharge sewage into the river, destroyed Central
Falls' Town Landing, drove sediment into reservoirs so Pawtucket
and Cumberland residents had to boil tapwater, and flooded streets
and basements. Initial damage reports ran into millions of dollars.
Natural Hazards In Rhode Island
• Today, high winds from a hurricane similar to the one in 1938 would cause over
$20 million in damages statewide for single-family structures.
• Rhode Island’s tornado risk is rated as an average of 1-5 per year.
• The Blackstone River basin is located in a high-activity storm track where
intense local storms have caused damages averaging over $200,000 per flood. Today,
100-year storm damages could reach over $3.5 million. A 100-year storm is one that in a
given year has a
1 percent chance of striking.
• All 39 communities in the state have been identified by the Federal Emergency
Management Agency (FEMA) as "flood-prone."
Dams at Risk
• Seven dams along the Blackstone River in Rhode Island present a significant
hazard. These dams are not necessarily in poor condition, but lives and property
downstream are at risk. Providence County has a total of 14 high-hazard dams.
Insured Value of Property
• Providence County has 783 flood insurance policies worth over $83.5 million.
There have been over 473 claims since 1978, including 51 repetitive loss properties. In
order to qualify as repetitive loss, properties must have sustained a minimum of two
events within the course of 10 years, with a combined damage expense equal to 25 percent
of the market value of the property.
