SALT LAKE CITY — Two years after a blistering legislative audit seared state water managers over their lack of knowledge about how much water Utahns are using and where, a follow-up analysis released Tuesday notes progress in data collection.

The audit found two divisions within the Utah Department of Natural Resources — water rights and water resources — have since conducted a significant overhaul on water data collection that emphasizes better collaboration and a process less likely marred by errors.

"Data accuracy issues seem to be on the decline because of efforts by state water agencies, the Legislature and local water systems to improve data collection," the audit by the Office by the Legislator Auditor General said. "However, some water systems continue to have difficulty reporting accurate water-use data."

The audit was presented to legislative members of the audit subcommittee Tuesday.

In 2015, a legislative audit highlighted severe problems with accurate water-use data in Utah, which is problematic given there are two state-sanctioned water development projects on the table — the Lake Powell pipeline and the Bear River. Both are being pursued on the premise that Utah's current water supply and delivery system will be inadequate to meet future water demand.

In the audit's aftermath, Gov. Gary Herbert said no large-scale water development projects would be pursued until an independent analysis of 2015 water use was completed. Herbert also directed additional funding toward state water agencies for site visits to public water systems to enhance data-collection efforts.

Utah water officials now believe the accuracy on water use has jumped from 50 percent to 90 percent after a number of internal agency improvements.

The latest audit, however, said there is much more work to be done.

Specifically, the audit says state agencies need to do a better job at "validating" estimates of secondary water use through trend analysis. While noting the Legislature passed a resolution encouraging water systems to move to universal metering of secondary water, the audit said lawmakers should go a step further and require it on new construction, when costs are relatively low.

Questions about Utah's water use are critical given the state's breakneck economic growth and with a population expected to nearly double by 2050. Utah surpassed the 3 million milestone in 2016, and its population growth rate from 2015 to 2016 was the fastest in the nation.

The state is also the second stingiest in the country for precipitation and is still suffering the effects of a prolonged drought, even though it did see some relief with a generous winter last year.

Herbert has said water is the state's Achilles' heel when it comes to growth, but some public water systems continue to use antiquated or inaccurate accounting methods on consumption or have not moved to more-effective conservation strategies.

The audit noted a need for:

• Systemwide adoption of tiered pricing.

• Reduction of property tax subsidies in financing of water systems.

• Adoption of basinwide conservation goals.

• Auditing unaccounted water use in water systems, such as leaks.

The Office of the Legislative Auditor General also released a follow-up audit on the state Division of Drinking Water. The prior report indicated that the division's sizing requirements for both indoor and outdoor use "capacity" were flawed and not based on actual demands of most local water systems.

While state officials concede the current system is problematic, they are finding it difficult to develop a new standard given the lack of reliable data.

In many instances, water systems don't monitor "peak day demand," which is the barometer used in sizing requirements that determine the amount of water a public system has to have on hand.

The problems have led to water systems that have excess capacity and inflated sizing requirements.

The new audit notes that the division wants to work with local water systems to more appropriately define capacity and sizing requirements. Such a move would require new rules and legislation, it noted.