Such a common thing it is, and yet almost impossible to grasp in its scope – the acres of impervious surface in Baltimore and across the state of Maryland.

Roads, highways, bridges, sprawling parking lots, sidewalks, driveways. The State Highway Administration alone maintains more than 17,000 “lane miles” (road length multiplied by lanes), and that does not include state roads within the city.

That’s a lot of hard stuff.

Considering all of it – the Baltimore Beltway, the Jones Falls Expressway, the Capital Beltway, Interstates 70, 95, 795 and 395, the parking lots of shopping centers, many of them mostly empty in the age of e-commerce – that’s thousands of acres of gray pavement blocking rainfall from being absorbed into the ground.

That leads to minor monsoons of stormwater running into drains and gutters and into Baltimore Harbor. Or into the runs and rivers that flow into the Chesapeake Bay.

And it takes all kinds of pollutants with it.

Farms have historically been a major offender, but farmers have made progress in reducing runoff, according to the Chesapeake Bay Foundation (CBF).

Stormwater, on the other hand, continues to pollute the bay.

“Research has long shown that stormwater runoff from roads contains higher concentrations of pollutants than almost any other sources,” the CBF says.

It’s one of the grave concerns expressed recently by opponents of Baltimore’s plan to relocate a city trash transfer station near the Jones Falls – that during heavy rains, runoff from the proposed facility will carry who-knows-what right into the waterway.

Efforts Mocked by Hogan

Flooding is the other major concern as climate change brings more extreme rainstorms – and more stormwater – to the cities and towns of the Mid-Atlantic.

Maryland has been trying to address the problem for more than a decade. It allows the imposition of stormwater management fees in the state’s most urbanized jurisdictions to pay for various initiatives to slow runoff pollution, an effort mocked by Larry Hogan as a “rain tax” during his successful campaign for governor in 2014.

But while legislators knocked some of the teeth out of the original law, the effort continues.

Local municipalities work on stormwater remediation, and some nonprofits and churches have taken on projects, such as rain gardens, to offset the effects of their parking lots on nearby water sources.

In its latest report, the Maryland Department of Environment (MDE) found that Baltimore City and the state’s largest jurisdictions were meeting, at various levels, long-term goals of turning impervious surfaces into areas where water can soak into the ground.

In all, according to MDE, nearly 43,000 acres of impervious surfaces have been restored so far, representing about 25% of the baseline goal.

That means there is a lot more to be done, starting with state property – all those roads and highways mentioned up above.

“Missed Opportunity”

On Friday, MDE issued a five-year stormwater discharge permit for the State Highway Administration, saying the permit is “designed to deliver economic opportunities for communities, cleaner waterways, and enhanced climate resilience.”

Soon after the permit was issued, however, three leading environmental groups declared it woefully insufficient at a time when the planet is warming and its inhabitants are being slammed by extreme weather.

“Maryland has missed a critical opportunity to reduce stormwater pollution running off the state’s highways, roads and bridges and into local waterways,” said the CBF, Chesapeake Legal Alliance (CLA) and Maryland League of Conservation Voters (LCV) in a joint statement.

The new permit, the groups said, “misses the mark on addressing climate change at the same time that Marylanders are enduring exceptionally heavy rainfall and flash flooding this summer.”

In its announcement, MDE, pointed to the $216 million in combined state and federal funding directed toward the SHA under the permit, promising that it will “support Maryland’s growing restoration economy while protecting vulnerable communities from flooding and pollution.”

The permit requires the SHA to restore 4,092 impervious acres with “green infrastructure such as stream restoration and tree plantings across the roadway network,” MDE said.

It also requires the SHA to “evaluate and report on restoration opportunities and progress in communities with environmental justice concerns, while meeting annual benchmarks to ensure steady progress.”

Under the new permit, MDE said, the highway administration will expand “collaboration with scientists and experts on shared monitoring studies – delivering better data, faster results, and smarter decisions.”

Say the three environmental groups: Not good enough.

No Match for Nature

The new permit takes “a minimalistic approach,” said Kim Coble, LCV executive director.

Coble and colleagues claim the state’s oversight of stormwater remediation by the most polluting jurisdictions has not kept pace with climate change.

The new SHA permit “fails to address significant deficiencies that were identified by experts in the draft permit last year, including use of out-of-date data, emphasis on stormwater practices that do not address the root cause of pollution, and a lack of information on emerging contaminants such as the ‘forever chemicals,’ perfluoroalkyl and polyfluoroalkyl substances (PFAS).”

The CBF, CLA and LCV wanted the highway administration to do a range of things to mitigate stormwater pollution, such as removing unused impervious surfaces and measuring the effects of polluted runoff on wildlife and their habitats.

“Maryland’s current stormwater regulations are no match for nightly thunderstorms and daily floods”  – Chesapeake Bay Foundation.

“Maryland’s current stormwater regulations are no match for nightly thunderstorms and daily floods,” Allison Colden, CBF’s Maryland executive director, said in a separate statement.

“We are disappointed the state did not capitalize on this opportunity to lead by example and demand effective stormwater improvements with tangible benefits. Because of this, one of Maryland’s largest pollution-reducing permits will not adequately reflect current climate impacts for at least another five years.”

Added CLA senior attorney Evan Isaacson, “This permit is not strong enough to help protect communities and streams from highly polluted roadway runoff and will not do enough to meet our bay goals.”

MDE Secretary Serena McIlwain pushed back, issuing the following statement:

“This permit strengthens our ability to protect the Chesapeake Bay and the businesses and communities that rely on it, manage stormwater in overburdened areas, and make our state an even more desirable place to live.”

She went on to promise that the permit will “help build a more competitive Maryland, creating good-paying jobs, protecting businesses and homes from the effects of climate change, and positioning our state as a national leader in clean infrastructure.”

On its website, MDE says the state’s most urban jurisdictions have raised and invested more than $1 billion in clean water infrastructure, while MDE’s Water Quality Finance Administration has guaranteed $117.8 million in low-interest loans to local governments for stormwater restoration projects.

Another $257 million in low-interest loans are pending for planned projects. In the years ahead, MDE expects Maryland jurisdictions to add another 19,000 acres to the impervious acres already restored under prior permits.

That sounds good, but here’s a little perspective:

Baltimore’s impervious surfaces alone cover about 23,000 acres, and nearly 2 million acres of the Chesapeake watershed – an area that encompasses Maryland and Virginia and portions of Pennsylvania, New York, West Virginia and Delaware – are impervious.

That’s a lot of hard stuff.

That’s a lot of runoff we’re continuing to direct into storm sewers and streams and, eventually, into the bay.