Over the past decade, nonprofits and state organizations have started recognizing that removing dams from rivers can actually help the environment by allowing fish to return to their original spawning grounds.

According to Laura Craig, director of river restoration at American Rivers, removing dams reconnects fish habitat, lowers water temperature, speeds water flow, increases dissolved oxygen — an important indicator of a river’s ability to support fish populations — and improves water quality for cities. New Jersey and Maine have both seen dam removal projects successfully boost fish populations, and now Delaware is getting in on the act.

For more than 200 years, different species of fish such as American shad and striped bass have been unable to return to their traditional spawning grounds in the Pennsylvania section of the creek about 25 miles to the north since a series of dams was built across the creek by early American settlers. This year, the fish will be able to swim past the site of a dam that was demolished by the city of Wilmington in Delaware last fall, allowing them to move as far as the next barrier, Dam 2, about three-quarters of a mile upstream, where large numbers are expected to create a sudden bonanza for anglers.

The return of shad and other migratory fish to the creek will not only restore an ancient natural rhythm but will also nurture other wildlife like bald eagles that prey on the fish, while their decomposed bodies, post-spawning, add nutrients to the waterway.

Delaware isn’t the only state committed to removing dams for the sake of the environment. In Oregon and California, four dams on the Klamath River are due for removal by 2022. And in New York State, where there are an estimated 2,000 dams in the Hudson River watershed between New York City and Albany, the state has committed $5 million for dam removal.