The Iowa Department of Natural Resources is giving the state high marks for managing its deer population and cleaning up lakes, but notes there’s plenty of room for improvement when it comes to the quality of rivers and streams.

The agency released a report card today that grades the state environmental efforts based on D.N.R. field data.  D.N.R. Director Rich Leopold says lakes earned a "B" while rivers and streams were graded at "C-minus."

He says a lake restoration program, launched in the state earlier this decade, is making a big difference. "The legislature’s been giving us some resources and we’ve got great planning…and we’re actually taking (lakes) off the impaired waters list," Leopold said. "In our streams and rivers, we do not have the same level of focus and coordination."

The report card gives Iowa a "B" when it comes to deer management. Leopold admits that some Iowans, depending where they live, might think the state deserves an "F" in that category. He says some counties are still overpopulated, but should be back a reasonable levels within a few years.

"Fourty-percent of Iowa is at or below desired (deer) population levels, while about 45-percent of our state is going to be at or below within a year or two," Leopold said.

"So, the vast majority of Iowa is going to be where we want it to be population wise and still maintain a world class deer herd." Leopold says the D.N.R. clearly miscalculated the state’s deer population several years ago.

"But, overall, what we’re doing in managing the deer population and bring that herd size down is working," Leopold said. The report card also gave the state a "C-minus" for nongame bird populations. Leopold says it’s not clear why those various birds are suffering.

"Largely, we don’t know," Leopold explained. "That’s part of the problem. We don’t have very good monitoring. Is it climate change? Is it habitat loss? Is it pesticide build-up? Is it depredation by natural predators like farm cats? There’s a lot of questions out there that we don’t know."

The D.N.R. graded the health of the state’s natural resources in eight subject areas. When averaged together, the report gives Iowa a grade point average of 2.7, or a "B-minus."

You can see the full report card here .