Brian E. Frosh, a Democrat, is the Maryland attorney general. Mark R. Herring, a Democrat, is the Virginia attorney general. Karl A. Racine, a Democrat, is the D.C. attorney general.

For all who cherish the Chesapeake Bay and champion efforts to save this national treasure, reports of improved oxygen levels and rebounding crab and oyster populations should be reason to take heart. Collective efforts of Chesapeake watershed states are bearing fruit, with water quality improving — but more progress is needed before the United States' largest estuary is truly out of the woods. Now, these hard-earned gains are threatened.

In September, Rep. Bob Goodlatte (R-Va.) introduced an amendment to the 2018 House appropriations bill that would prohibit the Environmental Protection Agency from spending funds to enforce the restoration plan known as the Chesapeake Total Maximum Daily Load. This deliberate sabotage was not Goodlatte's first attempt to thwart the collaborative federal-state efforts in the Chesapeake Bay.

According to Goodlatte, the EPA should be stripped of its clear authority under the Clean Water Act to enforce pollution limits to which all Chesapeake Bay jurisdictions have agreed and dedicated years of investment. Notwithstanding strong bipartisan opposition, including 20 members from the bay watershed, the amendment survived. The appropriations bill is now with the Senate.

Goodlatte's poison-pill amendment is just the latest in a string of attacks by the Trump administration and some members of Congress to weaken or destroy bedrock environmental laws. The Chesapeake Bay Total Maximum Daily Load is a quintessential example of how the federal government should use the Clean Water Act's authority and framework to join state partners in restoring and maintaining our country's waterways.

After 25 years of extensive but ultimately unsuccessful restoration efforts, virtually everyone agreed that a new strategy was required for the Chesapeake Bay to be saved. The prospect of losing the bay, with a "natural capital value" of $107.2 billion annually and enormous recreational and environmental benefit to millions of Americans, prompted widespread public outcry and galvanized regional leaders. All seven watershed jurisdictions — Delaware, Maryland, New York, Pennsylvania, Virginia, West Virginia and the District — worked with the EPA to develop a new Chesapeake Clean Water Blueprint. Designed to ramp up restoration and pollution-control efforts, the blueprint identified steps to reduce nitrogen, phosphorus and sediment loads to improve water quality in the bay and its tributaries.

Unlike prior efforts, however, this blueprint included a crucial accountability framework and federal backstop authority to ensure that each jurisdiction actually does what it promised and investments made by all states are not wasted. Far from the dictatorial overreach Goodlatte alleged, the accountability framework simply contemplates that the EPA will take certain actions if a jurisdiction fails to meet its commitments. Moreover, the Total Maximum Daily Load — or pollution diets — were not punishment or randomly assigned, as Goodlatte asserted, but rather were developed after an extensive public process, using state-of-the-art modeling tools and monitoring data, peer-reviewed science and close interaction with each jurisdiction. When special interests outside the bay watershed then attacked the blueprint, we and other bay states successfully defended the plan, which the court determined to be a lawful example of cooperative federalism.

The Senate is putting together its version of the EPA's budget, and positive indications suggest it will reject the Trump administration's efforts to financially gut the bay restoration program. While the administration's budget would eliminate all $73 million in funding, the House bill provides for $60 million, and Senate appropriators have signaled they are likely at least to match this allocation.

Whether the Goodlatte amendment will survive, however, remains uncertain and, thus, provides Chesapeake Bay champions a critical opportunity to make their voices heard. We must make clear the importance of our region-wide, collaborative approach and the crucial role the federal government must continue to play to ensure that all actors are working together toward the common goal of restoring this vital watershed.

As the first president to sign in to law protections for clean air and water 50 years ago, President Lyndon Johnson counseled (on signing the Wilderness Act): "If future generations are to remember us with gratitude rather than contempt . . . we must leave them a glimpse of the world as it was in the beginning, not just after we got through with it."

For our children and future generations, let us continue the collaboration and vigilance necessary to return the Chesapeake Bay to what it once was, in all of its beauty and bounty.