More tourists, and more kamaaina wear-and-tear have taken their toll on state and county parks, and it soon will become critical to find a new source of revenue to restore them to decent condition.

It appears that the primary sources won’t be enough, even with an increase in tourism refueling the tax tanks — meaning that charging fees to nonresidents users may be a reasonable solution.

According to preliminary figures from the Hawaii Tourism Authority, arrivals in April rose nearly 7% but their spending fell by almost as much — 6% — compared with data from a year earlier.

Increasingly these visitors, 856,250 in all, include tourists who enjoy going off the beaten path. Hawaii’s trails and lesser-known parks are sustaining more traffic, the independent-minded adventurers being directed there by social media postings.

Charging fees is not a new idea, and there already has been significant movement in this direction, at state and county levels.

In the immediate aftermath of the Great Recession a decade ago, the administration of Gov. Linda Lingle proposed a “Recreation Renaissance” program for the Department of Land and Natural Resources that explored various means of monetizing state recreational resources to support their upgrades and maintenance.

It also required some state investment, funds that did not materialize. But it set off some exploration of various user fees; for example, the department’s Forestry Division last year held hearings on proposed rules on fees for campground rentals, parking, entrance and other activities (dlnr.hawaii.gov/forestry/frs/rulechange/guide-fees-and-charges/). Those surely need to go into effect.

Precursor to the latter-day fees discussion was the implementation of $7.50 daily charges for admission at Hanauma Bay that are applicable to nonresidents age 13 and up (all preteens enter free, as well as older youths and adults with proof of Hawaii residency). Parking fees for all ($1 per vehicle) also are assessed.

It’s a hybrid, administratively: The City and County of Honolulu regulates it as a nature preserve, but because of its famous marine-life resources it is also classed as a state park.

In any event, the fees are intended to help sustain the natural resource, which bears up under traffic from thousands of visitors annually. Further, the reef fish that attract all the attention are given respite during park closures each Tuesday and on Christmas and New Year’s Day. Such strategies could be considered for other natural resources that are in danger of being tapped out.

For its part, the city has come under criticism in recent years, allegations that the Hanauma fee revenue is used for purposes other than for bay maintenance. Accountability for that will become critical going forward, in the event that revenues continue to drop.

It is not only the avid tourists who prompt this call for preservation efforts; recreational resources are heavily used by all. And out of concern about vandalism and illegal activity by homeless campers, the city early this year responded by locking down dozens of parks.

Fortunately, awareness of diminishing returns from tourist spending despite rising visitor counts has reached those in key leadership roles. Chris Tatum, the Hawaii Tourism Authority’s new CEO, has underscored that HTA priorities include the need for a “long-term sustainable tourism strategy.”

This means, of course, that state investment in tourism directed at pumping up the raw visitor numbers also must work to keep its natural resources healthy. Everyone — visitor and kamaaina alike — should be able to expect that.