Howard County has voted to require developers to have more vigorous stormwater management plans to deal with flooding that comes from torrential rains.

After the second so-called “thousand year flood” in two years in historic Ellicott City, Maryland, in 2018, many questioned whether recent development had played a role. Now, Howard County has voted to ensure developers play a role in lessening future flooding.

The Howard County Council passed two resolutions Monday that will raise the standard developers must meet in future projects for stormwater management, or how well the land is able to move and store the large amount of water that comes with torrential rains.

Both resolutions apply to the Tiber Branch and Plumtree Branch watersheds, which flow in Ellicott City on the banks of the Patapsco River.

In July 2018, the council placed a moratorium on development in the Tiber and Plumtree watersheds. The moratorium expires this month.

Under the new resolutions, proposed by Howard County Executive Calvin Ball, future development will have to be able to handle the amount of water that fell during the 2016 flood event that overwhelmed downtown Main Street of the hilly former mill town.

In addition, developers whose properties do not meet the higher stormwater management standards will be required to pay fees that are twice as high.

“These resolutions will ensure that developers are building the infrastructure necessary to manage the rainfall from increasingly severe weather,” said Ball in a news release.

The resolutions are in addition to Howard County’s multiyear plan, which includes razing four historic buildings on the most flood-prone section of lower Main Street. The plan involves building a tunnel which aims to divert water from Main Street during heavy rainstorms.

Ball’s plan doesn’t attempt to eliminate future flooding entirely, but reduces the amount of water on Main Street.

Editor’s note: This story has been updated to clarify the amount of stormwater developers will need to manage for future projects.