A far-reaching measure before California voters in June would authorize the state to borrow $4.1 billion for investments in outdoor recreation, land conservation and water projects. But Proposition 68, which needs a simple majority vote to pass, is not your typical water and parks bond measure.

The proposition steers clear of flashy, big-ticket items like new dams and major state park expansions. Instead, it favors upgrading smaller neighborhood parks, protecting local greenways and open space and cleaning up polluted riverbanks and groundwater supplies, largely in urban and suburban areas.

While the Bay Area would get a slice of the money, including funding for the preservation of such crucial watersheds as the Russian River, Los Gatos Creek and San Francisco Bay, the financing would skew toward low-income cities in the Central Valley and Southern California.

“We’re making the investment in our underserved communities a priority,” said Mary Creasman, state director of government affairs for the Trust for Public Land, which helped draft Prop. 68. “That’s different than what we’ve seen in the past.”

One of the proposition’s biggest chunks of funding — $725 million — is designated for the creation and expansion of parks and recreation centers in neighborhoods short of those opportunities. The money would be allocated through competitive grants with preference for the “park-poor” places in the Central Valley and Inland Empire as well as in desert and rural communities. The money could pay for pools, gyms, youth programs and open space.

Disadvantaged areas would also have priority in receiving many of the proposition’s remaining funds.

In total, roughly a third of the measure’s bounty is designated for parks and other recreation uses, a third for protecting natural habitats and a third for water and flood-control projects.

Prop. 68 was authored by state Sen. Kevin de León, D- Los Angeles, who as president of the Senate last year fought to correct for the “underinvestment” in parks, wildlands and water systems in poorer communities, mainly in the southern half of the state. De León, a U.S. Senate candidate this year, called the initiative the first bond measure to focus on “social equity.”

The Legislature last year approved the proposition for the June 5 ballot with the backing of Gov. Jerry Brown.

The measure is widely supported by cities, chambers of commerce, environmental groups and water suppliers from both Southern California and Northern California, all of whom cite at least some benefit for their area.

Bay Area communities, besides being eligible for a variety of competitive grants, are guaranteed at least $250 million.

More than $200 million would be set aside for restoring and improving water quality in the San Francisco Bay and the Sacramento-San Joaquin River Delta. About $3 million would go to habitat restoration along the Russian River, and another $3 million would go toward protection of Los Gatos Creek and the Guadalupe River. Also, state parks in the East Bay would get at least $10 million for improvements.

Other dedicated funds include $60 million to protect high-elevation watersheds in the Sierra Nevada, $200 million to restore Southern California’s Salton Sea and at least $50 million to upgrade levees in the delta. Prop. 68 explicitly states that no money would go toward Brown’s controversial tunnel project, which would move water through the delta from Northern California to Southern California.

The proposition is the first water and parks bond measure since 2006, when voters approved the $5.4 billion Proposition 84. Eight years later, voters approved a water-only bond measure, Proposition 1, which committed $7.1 billion to projects seeking to help drought-proof the state, including new dams and reservoirs. The Prop. 1 money is still being doled out.

General obligation bonds are commonly used by governments to finance infrastructure projects they can’t immediately afford. The bonds are essentially loans from investors who the government agrees to pay back, with interest. In California, such borrowing must be approved by voters.

The main opposition to Prop. 68 is from fiscal hawks who say the state shouldn’t be taking on new debt, especially for upgrades to parks and water systems. These expenses, they say, should be covered by the state’s annual budget.

“If we hit a recession and our revenues drop off, all of a sudden our debt service goes way up,” said Jon Coupal, president of the Howard Jarvis Taxpayers Association, which opposes the proposition.

In November, California voters are likely to see another proposed bond to fund water projects. The secretary of state’s office announced last month that proponents of an additional $8.9 billion of borrowing, many from the agricultural community, had turned in the required signatures to put an initiative on the ballot.

The new, privately backed measure would be similar to the Legislature’s measure in supporting groundwater cleanup and water recycling, often for disadvantaged communities. But it would go a step further to help with larger water projects.

The initiative, for example, would fund improvements to Central Valley irrigation canals and upgrades to reservoirs, including Oroville Dam. The measure, though, would not pay for new dam construction.

The Association of California Water Agencies, which represents more than 400 water suppliers across the state, has endorsed both the June and November bond measures as necessary for maintaining California’s sprawling water infrastructure.

“Intelligent voters ought to think of the measures as a pair,” said Tim Quinn, executive director of the water agencies. “Together they give a substantial amount of momentum for things that are important for California.”

Kurtis Alexander is a San Francisco Chronicle staff writer. Email: kalexander@sfchronicle.com Twitter: @kurtisalexander