WASHINGTON – U.S. Senator Ben Cardin (D-Md.), Chairman of the Senate Environment and Public Works Subcommittee on Water and Wildlife, has introduced legislation to better control the harmful volumes of polluted stormwater generated from our nation’s federal aid highways. Highway stormwater is a growing threat to water quality, aquatic ecosystems and the fish and wildlife that depend on the health of these ecosystems. The force of excessive stormwater flows and volumes from highways presents greater flash flood risks, leads to rapid erosion of water channel streambeds and stream banks, while damaging and shortening the useful life road and water infrastructure. Senator Cardin has introduced a bill, S. 2457, the Highway Runoff Management Act, to address these concerns.

“Freakishly strong storms, polar vortexes, baseball-sized hail, three-mile wide tornadoes and other unusual weather are becoming more usual. Rainfall and ice melt on hard surfaces like roads and highways have a very destructive and turbulent effect on nearby waterways and infrastructure. As extreme weather events triggered by our changing climate become more frequent it is imperative that we incorporate better designs into our infrastructure to better handle these types of events.

“Stormwater runoff poses a grave threat to our environment, public health and budgets. Organic and inorganic pollutants wash off the hardened surfaces in urban areas and flow into local rivers and streams. These contaminants are legitimate threats to water quality but the greater concern is the sheer volume and rapid flow rate in which stormwater leaves these hard surfaces and enters our waterways. Our goal is for states to improve the designs of new highways to better manage stormwater and therefore avoid the costly damage that poorly managed stormwater causes to infrastructure and nearby streams, rivers and coastal waters.”

According to U.S. Geological Survey: an inch of rain on one square foot of pavement produces 1.87 gallons of stormwater. Using the Federal Highway Administration (FHWA) design standards for interstate highway lane and shoulder widths – 12 feet per lane, 10-foot right shoulder (2x), 4-foot left shoulder (2x) – 10 miles of a four-lane interstate highway generates nearly 2.5 million gallons of polluted stormwater for every inch of rain. Applied to the Potomac and Anacostia River Watersheds: the Capital Beltway, not including its 48 interchanges, generates nearly 30 million (29,920,946) gallons of polluted stormwater for every inch of rain that falls on the 64 mile 8-12 lane interstate highway loop.

S. 2457 Highway Runoff Management Act

to Protect Water Resources and Private Property and Preserve Highway and Water Infrastructure

Senator Cardin’s Highway Runoff Management Act would require states to analyze the hydrological impact federal aid highways are having on water resources and development approaches to reducing the destructive impact of heavy stormwater runoff volumes and flows.

Impervious road surfaces are extremely efficient conveyances for stormwater. Rapidly moving high volumes of untreated polluted stormwater runoff that rush off of road surfaces, erode unnatural channels next to and ultimately underneath roadways comprising the integrity of roadway infrastructure, increases stress on storm sewer systems shortening the useful life of this infrastructure and ultimately degrade nearby lakes, rivers, streams, and coastal waters both through heavy erosion of streambanks and streambeds and the discharge of untreated pollution into these waters. Many federal aid highways contribute directly to this costly problem, yet the responsibility and expense for remediation and repair to the damage highway runoff causes to water resources and water infrastructure is borne solely by water utilities or state natural resource agencies with very little if any help from highway authorities whose infrastructure is a leading cause of the damage.

Section-by-Section

Section 1: Short Title: the name of this bill is the “Highway Runoff Management Act

Section 2(a): The legislation amends Title 23 (Highways) by adding an new section (“330: Federal-aid highway runoff management program”) to Chapter 3 (General Provisions).

Sec. 330

Subsection (a): Defines terms in the bill including:

(1)               “Covered Project,” reconstruction, rehabilitation, reconfiguration, renovation or major resurfacing that at a minimum increases the impervious surface area of the project area or increase imperviousness by 1 acre or more.

(2)               “Erosive Force,” is threshold flow and volume rate by which channel and bank material becomes detached, which is usually a 2-year storm event.

(3)               “Highway Runoff,” is stormwater discharge that lands on and flows off of a federal aid highway and into a nearby water body or municipal stormwater system.

(4)               “Impacted Hydrology” is the stormwater that is generated from a covered project area.

(5)               “Management Measure,” are the means used to reduce flow and volume of stormwater from a covered project area.

Subsection (b): “State Highway Stormwater Management Programs,” Requires states to analyze the impact highway runoff is having on the hydrology of the nearby water resources and develop and implement the appropriate stormwater management measures to reduce the impact highway runoff is having on these resources.

Subsection (c): “Guidance,” Instruct FHWA to develop guidance for states to follow to conduct the required analysis and management activities prescribed in (b).

Subsection (d): “Reporting” requires states to report back on the progress made under the applied stormwater management activities unless, such reporting is already being done through an existing regulatory permit.

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