Connecticut environmental officials are urging residents to use caution around waterways after recent heavy rainfall.

The Connecticut Department of Energy and Environmental Protection is warning people to avoid swimming in waters that are not designated and officially open for recreation.

Officials said runoff flowing into rivers, lakes and other bodies of water after storms can carry bacteria, metals, oils and grease.

Residents are being urged to avoid recreational waterways until water sampling is completed.

The weather has already prompted several beach closures.

All Stratford beaches are closed until Friday because of the recent rainfall.

Eichler’s Cove Beach in Newtown was closed Tuesday, and town officials had not announced Wednesday whether it would reopen.

DEEP officials said water quality testing is underway following the storms.