The state has more than 125,000 miles of rivers and streams and 57 major watersheds, as well as numerous groundwater aquifers that some communities such as Baton Rouge depend on for drinking water.

“Managing that water is going to take some critical decisions,” said Bryan Piazza, director of freshwater and marine science with The Nature Conservancy.

In an effort to help, The Nature Conservancy released a new online freshwater database and mapping tool that combines millions of records to give a better overview of the state’s freshwater system. The website is http://freshwaternetwork.org?subject=">freshwaternetwork.org.

The site includes years of information about rivers, streams, bayous, canals, dams, reservoirs, land use, water flow, fisheries and water quality.

In some cases, such as fisheries and state Department of Environmental Quality information, the data cover almost 50 years.

“It’s never all been in one place before,” said Keith Ouchley, director of The Nature Conservancy of Louisiana. “We wanted to provide a tool that provides information for them to do this planning.”

Unlike much of the country, Louisiana’s concern about water usually involves keeping it out of communities rather than desperately seeking some way to find more to use.

However, that thinking is starting to change as the state Water Resource Commission, conservation groups and state agencies see a greater need to develop science and policy to manage the state’s water resources.

“In Louisiana, we have lots of water — a t least, we think we do,” Piazza said. “Currently in Louisiana, we don’t really have a good idea of how much water we have or how much we should have and how much it should cost.”

The Nature Conservancy started work on the project two years ago, meeting with agencies and others to make sure what they were developing would be useful, Piazza said.

On Thursday, The Nature Conservancy launched the website, which allows the public to look at watershed health, the effects of canals and levees on water sources, pollutants, fish populations and more. The Nature Conservancy continues to work on other applications that will allow people to research how connected groundwater is to surface water, how freshwater systems upstream connect with coastal ecosystems and how changes made upstream can affect resources downstream, he said.

The system allows people to research water resources across the state by DEQ subsections, parish, U.S. Congressional district and even an individual address. Another feature allows someone such as a planner to draw a custom outline for consideration for various projects.

“We built this system for decision-making,” Piazza said.

Karen Gautreaux, director of government relations with The Nature Conservancy, noted that although all of this information was available to the public, there never had been one place where it could all be accessed. The information will be useful for the state’s Water Resource Commission.

“The Freshwater Assessment will be an important asset in helping our citizens learn more about the water in their community, and will help public and private partners make science-based decisions that help protect and conserve our water resources to meet current and future needs,” Scott Angelle, Water Resources Commission chairman, said in a news release.

As the system continues to be developed, more information will be added to allow planners to create “water budgets” that essentially show how much fresh water exists, current uses and how additional uses will affect things like water flow and availability to downstream users.

Water-flow modeling for the state, nutrient management, fish biodiversity and freshwater connections to the coast should be available on the site in 2015.

About $2 million has been spent on developing this Freshwater Assessment through private and foundation funding, Ouchley said, with help from other partners, including the Research Triangle Institute International, Southern Illinois University, National Science Foundation and the Baton Rouge Area Foundation.

Follow Amy Wold on Twitter, @awold10.