The three major projects needed to establish an adventure park along the rivers in downtown Des Moines will generate direct spending in the first five years nearly equal to the original investment, a new study found.

Beyond the first five years, the attractions downtown are likely to bring in $26 million to $32 million a year in direct spending, including a multiplier, the study found. They are expected to draw at least 158,000 visitors a year, based on what backers consider conservative estimates from consultants.

Capital Crossroads consultants Johnson Consulting of Chicago found that the $106 million investment to remove three downtown dams and replace them with areas for kayaking, fishing and other pastimes would bring $104.4 million in direct spending in the first five years. The work is the highest profile and perhaps most expensive of a much broader plan to create 86 projects in 14 cities and counties to turn 150 miles of waterways in Central Iowa into recreation sites.

The adventure park also is expected to offer zip lining and skateboarding.

The total economic impact in the first five years, including direct, indirect and induced spending, would be $173.8 million, the study found.

Employment related directly to operating the attractions would be the equivalent of 151 full-time jobs in year one, rising to 202 by year five, with payroll growing from $8.3 million to $12.6 million.

Johnson expects $7.3 million in tax payments from the project the first five years combined, with $1.7 million a year starting in year five. That includes sales tax, hotel/motel tax and excise taxes.

The project, which eventually will be run by a newly formed entity, is being coordinated by Capital Crossroads, the Des Moines Area Metropolitan Planning Organization, the Greater Des Moines Partnership, the Great Outdoors Foundation and the Community Foundation of Greater Des Moines.

In an interview, Community Foundation President Kristi Knous said the spending will help more than downtown Des Moines, feeding visitors to area attractions such as the Outlets of Des Moines, Jordan Creek Town Center and Adventureland. “This will be a multiday attraction in many cases,” Knous said, predicting added business for hotels and motels.

Johnson Consulting previously did studies on the economic impact of the Iowa Speedway, the Iowa Events Center and the downtown Hilton hotel.

Knous and Greg Edwards, president and CEO of Catch Des Moines, said the projections for use and spending seem conservative in comparison to the water attractions in Ann Arbor, Mich., which is a far smaller market.

Backers of the water trails expect to release a business plan assessing operating expenses, and a separate look at fundraising potential, in January. Work on fundraising is expected to take 18 months. “We’re looking at the money to be one-third private, one-third local public and one-third state and federal,” Edwards said.