Minnesota has spent $761 million from the state's 2008 Legacy Amendment to clean up and protect lakes and streams, but it's too soon to know whether the funding has made any difference.

But clarity should emerge in the coming years as the state implements a strategic plan tracking water-quality changes watershed by watershed, the Office of Legislative Auditor said in a report Monday.

Meanwhile, some of the government entities charged with spending the special sales tax funds could do a better job of reporting on how the money is used, the report said.

Last year legislators directed the auditor's office to answer questions that have frustrated them since the Legacy Amendment was passed by voters in 2008. Can the state measure the outcomes for water quality? What good has the money done? And is the distribution of the money transparent?

By and large, the report concluded, state and local government agencies do pretty well in tracking distribution and keeping the process open to the gaze of the public and the Legislature.

But a handful of state agencies systematically failed to report at least one required piece of information — primarily whether the Clean Water Fund money was spent directly on projects or on administrative costs, the report found. It recommended that the state's Legislative Coordinating Commission do more to track data reporting for the Legislature.

The biggest question — whether the money is improving water quality across Minnesota — cannot yet be answered, the auditor's office said. In part that's because it takes many years to change the land-use practices that cause water pollution, and even longer for those changes to show up in water quality.

Plan in place

Only now does the state have a strategic plan in place to track such long-term changes, a 10-year cycle of measurements on each of the state's 80 major watersheds.

By far, the largest chunk of Clean Water funds, 36 percent, has gone to the state Board of Water and Soil Resources. It has spent $276 million, primarily to buy conservation easements in agricultural regions of the state to protect groundwater and surface waters from nitrate and phosphorus pollution, and to fix septic systems and control stormwater runoff.

The report estimates that those funds have reduced nitrogen and phosphorus pollution by 256,000 pounds a year. But that's only a tiny fraction of the reductions needed to bring the state's waters back to the point where they are swimmable, fishable and drinkable, the report said.

The second largest chunk, $206 million, was spent by the Minnesota Pollution Control Agency, primarily for the testing and monitoring required to identify polluted waters, and to measure change over time.