If the funding woes continue, "this revered agency would have to start cutting staff," said Jeffrey Featherstone, a Temple University professor and former deputy executive director at the commission. "It would be on a death cycle."
Two other commission member states, New Jersey and Delaware, have paid or are expected to. Although New Jersey had threatened to withhold funding last year if drilling regulations weren't passed, it didn't.
But because of political wrangling at the national level, the federal government - the commission's fifth member - has failed to pay its portion every year but one since 1998. Its cumulative shortfall is now more than $9 million.
Maya van Rossum, the Delaware riverkeeper, said it seems clear Pennsylvania's failure to pay "is arm-twisting because of the gas drilling regulations."
She called it a "myopic" strategy given the commission's proven value to the river basin and the states in it by regulating water withdrawals, maintaining water quality, and managing droughts and flood mitigation.
"Frankly, it's going to result in putting us right back into the water wars," she said. The commission was formed as a way to broker disagreements among the four states about how to divvy up the river water.
Commission executive director Carol R. Collier said she was "worried . . . we're really in a nonsustainable situation." Payroll makes up nearly 80 percent of the budget, and the commission has been tightening its belt for years.
Collier said she was trying to convince the federal Office of Management and Budget "that there is not only a contract that they need to adhere to," but how cost-effective the commission's work is.
Pennsylvania Department of Environmental Protection spokesman Kevin Sunday said $400,000 in DRBC funding was frozen when Gov. Corbett called for cuts. "We felt the DRBC could absorb this one-time reduction . . . and still be able to meet its core mission," he said.
He said now that New York and the federal government were shortchanging their payments, Pennsylvania was paying far more than its 25 percent fair share of the DRBC budget.
Corbett's proposed budget for next year restores the state's fair share of commission funding, minus 5 percent. That "is in line with the present economic situation and the governor's call to cut spending by 5 percent," Sunday said.
The governor went lighter with cuts to the Susquehanna River Basin Commission, which has been issuing permits for water withdrawals related to natural gas drilling. It was cut by only 10 percent.
And the Susquehanna commission, unlike the Delaware commission, is allowed to charge fees, which amounted to about half its $12 million budget in 2010. That's more than double the $5.6 million the Delaware commission plans to spend this year.
The commission had declared a moratorium on drilling in the Delaware basin until regulations could be adopted. They were proposed in December 2010 but the process stalled in November, when a meeting to vote on revised regulations was canceled.
Contact Sandy Bauers at 215-854-5147, email@example.com, or follow @sbauers on Twitter. Read her blog at philly.com/greenspace.