July's deadly flash flood in historic Ellicott City is prompting Howard County officials to reconsider the impact of development on the area's waterways.
The County Council will vote on a measure next month that would temporarily halt commercial and residential development in the Tiber-Hudson watershed for nine months.
The freeze, proposed by Councilman Jon Weinstein, who represents the historic district, will push the county to critically examine whether development "poses additional threats to the safety of people, businesses and property," he said.
The Kittleman administration says it is too early to determine the relationship between development and flooding, according to Andy Barth, the county's press secretary.
The administration will wait until the county completes hydraulic studies of the watershed and other analyses before it determines the impact of development on flooding.
"It is important to also recognize that much of the development in the Tiber/Hudson watershed predates various stormwater controls. The county will need to determine through the studies underway the contribution to flooding by older development versus newer development," Barth said.
Weinstein said he believes development contributed to the flood, which created a ravaging river through the historic district on July 30. The flood killed two people, impacted nearly 90 businesses and displaced 190 residents. The halt covers future building and grading permits and would go into effect 61 days after it is enacted.
Still, no amount of flood management could have stopped the natural disaster, he said.
"We can't stop six-and-a-half inches of rain falling from the sky in two hours," Weinstein said. "Water will go where water will go."
By design and typography, the town is prone to flooding.
Development has increased around the river town, which was designed in 1772 to support a flour mill by speeding up the flow of water that courses under the low-lying district's buildings.
Compared to other jurisdictions in the state, Howard County has a high portion of land dedicated for development. According to studies by the Maryland Department of Planning, nearly 51 percent of the land in the county is developed.
Developers have submitted more than 100 proposals to build homes, shopping centers and other buildings in less than 3 square miles around Ellicott City since 2001, and most applications have been approved. Dozens of those developments are near the Tiber and Hudson streams.
The area targeted for the freeze extends south of Bonnie Branch Road, north of Interstate-70 and west of Route 29 in some places, bordered by the Patapsco River to the east, according to a map attached to the legislation.
Several projects have submitted new applications for subdivisions or development since July 1.
One proposal that lies within the zone outlined in the bill — to create 13 new single family lots on Church Road in the Ellicott City historic district — is slated to go before the Planning Board next week. Engineer and landscape architect Stephanie Tuite, a partner at a consulting firm involved in the project, said it's too early to tell if the legislation would affect the site's development timeline, which is still far from construction-ready.
"It is a concern but it's not an immediate concern for us," said Tuite, of the firm Fisher, Collins and Carter Inc.
Tuite added that while she shares concerns about flooding, she's not sure about the bill. "I know what they're trying to achieve but I don't know that it will achieve what they're trying to achieve," she said.
Katie Maloney, chief lobbyist for the Maryland Building Industry Association, said she has not read the legislation but that the organization is generally concerned about moratoriums, which create backlogs and can be costly for developers.
New construction often must follow stricter stormwater restrictions implemented in recent years, which she said helps to address the problem.
"We believe it's counterproductive to halt development just for the sake of trying to resolve a flooding issue," she said. "We think the problem is much deeper."
But a temporary halt to new construction could give officials time to assess the magnitude of the problem and the adequacy of current stormwater rules, said Bob Smith, a Columbia-based principal at the NAI KLNB real estate brokerage, who focuses on commercial and industrial properties.
"A moratorium based on new development within the watershed is probably a rational approach," he said.
By design and typography, Ellicott City is prone to flooding.
Twice in the last five years, streams that feed into the Patapsco River have overflowed, raising concerns about stormwater runoff from development in and around the Tiber-Hudson watershed.
But stormwater runoff from new development is only part of the challenge.
Older developments were built at a time when state and federal regulations required little to no stormwater management, studies show.
Twenty years ago, state and federal regulations focused on managing the quantity, not the quality, of runoff.
That approach used a curb and gutter system to move stormwater off of streets and buildings as quickly as possible, discharging runoff into water bodies, according to studies by the Chesapeake Bay Foundation.
Since then, the state has shifted to larger stormwater structures like ponds and man-made structures designed to catch and hold water.
The unique challenge in the historic district is that stormwater management must happen outside the flood-prone area in order to help it cope with future rains.
"The work has to be done outside the district if we want to catch the rain and keep it there," Weinstein said. "We have to follow the tributaries along the way."
Officials have acknowledged the county's approach to handling stormwater runoff has been piecemeal in some parts of the county.
As it works on long-term solutions, Barth said the county is installing temporary curb and gutter structures and expanding storm drains to reduce the impact of storms in the area.
Earlier this year, Weinstein and County Executive Allan Kittleman established a workgroup to explore ways to encourage businesses to manage stormwater runoff.
Kittleman also established a workgroup to examine flood control tactics in historic Ellicott City. That group's recommendations, submitted late last year, will guide the county's future strategy, Barth said.
Nearly 70 percent of the county's stormwater projects fall on commercial property.
So far, most of the county's stormwater projects have been on county land where projects are not hampered by limited property access rights.
Weinstein is also calling on the county to suggest policy changes to protect the historic district from future flood events.
His bill asks the county's Department of Public works to study the flow of water draining from the watershed using hydraulic and hydrologic analysis that typically include flood plain mapping, runoff analysis and designs for flood protection channels.
The county has already begun these studies. Much of the county's flood-mitigation work will depend on whether or not the county receives federal disaster aid, Barth said.
Still, Weinstein hopes the moratorium allows the county to "take a fresh breath" from the devastating flood.
"A moratorium now allows us to take a step back and look at this issue more comprehensively," he said.
The Council will hear testimony on Sept. 19 in the George Howard building in Ellicott City. To sign up to testify, go to apps.howardcountymd.gov/otestimony.
Baltimore Sun reporter Natalie Sherman contributed to this story.This story has been updated.