An Iowa State University study on the "Economic Value of Iowa's Natural Resources" estimates the activity within the state's parks, lakes, and trail systems generate about $2.63 billion annually in spending.
The study added, the multiplier effect of such activities could translate to more than 27,400 jobs and $580 million in income.
Not included in the 2007 study was the recreational use on Iowa's rivers. This summer's floods have brought attention to the waterways, but not the kind of attention river enthusiasts and state lawmakers wanted to see or promote. Before the floods, the legislature this past session passed, and the governor signed, a $12 million investment for communities to improve their riverfronts and use these "natural" assets to their economic benefit.
There are 72,000 miles of rivers and streams in Iowa ... many of them navigable by owners of the some 34,000 registered small, non-motorized watercraft in the state.
To help make rivers more attractive and accessible to current river users -- and to attract future visitors – the Iowa Department of Natural Resources has increased the number of river access points ... and launched a $200,000 Dam Safety Program for portage construction and installation of warning signs to call attention to the dangers of being in the water too close to a low head dam.
Ryan Hanson, volunteer, Boone: "There's no way to tell it was even here you know, from upstream if you weren't from around here you wouldn't have even known it was there and then by the time you see it, it's too late."
Luke Wright, Iowa DNR: "They're very deceiving because they have a hydraulic action where it rolls down under there. So it's very difficult to get back out once you're in."
In 2007, six people died in dam accidents.
There are nearly 200 low-head dams on Iowa rivers. While most are no longer used to create hydraulic power for long abandoned businesses once near rivers' edge, the dams are too expensive to remove.
With portage trails and signage ... the hope is "if it is built, more of the public will come."
Luke Wright, DNR: "Rivers have been an untapped source of recreation for years. Once they know that they're signed and they're safe and they know where things are, you're going to find a lot more people getting out and using them."
And once more people come to the river, many hope for a ripple effect on local business. For example, this small businesses near the new portage at the Fraser dam -- hopes to prosper with the river enhancements.
Art Steinberg, Fraser Bait Shop: "I think it will help me out a lot because I think there will be more people going over there now because its easier to walk down."
The increase in recreational river traffic may be due to the desire to enjoy a wilderness experience close to home … get a little peace and quiet … with the possibility of observing some of the river wildlife. Whatever brings people to the river, most want to see clean water.
Over the last decade, many river enthusiasts have volunteered for river clean-ups and removed tons of trash from the water. One of the largest organized Iowa cleanups is the annual weeklong Project AWARE. Some of the trash is "sculpted" into art … and displayed at the Iowa State Fair.
But pollution in Iowa's rivers is not always visible. There is often e-Coli and ammonia contamination coming from aging municipal sewage treatment facilities that have at times sent diluted raw sewage directly to rivers and streams.
There is also contamination from agricultural runoff. Such pollution put the Iowa River on a national "endangered rivers" list.
Jennifer Severin, American Rivers: "It's the ag runoff as you well know that makes the river endangered and dirty and unswimable."
In 2007, the national advocacy group American Rivers listed the Iowa River -- which flows from the north central part of the state to the southeast -- as one of the top ten "most endangered rivers" in the country.
Jennifer Severin, American Rivers: "And it really sheds a national spotlight on rivers and helps those folks who are on the ground who have probably been working on river issues for a long time. It just helps propel the issue forward for Iowans to say, 'Oh my gosh, its really true. The Iowa River is really endangered. We need to do something about it'."
Some things have been started to improve Iowa's rivers – at least on paper. More than 850 miles of rivers and streams have been newly designated by the DNR as having "recreation use protection" ... which means those waterways need to be made safe for human contact.