Voters in fast-growing Texas come face to face with the future today, when they will be asked to vote on ballot issues ranging from water and nuclear power to land development.

In other states, voters will grapple with decisions on a variety of issues ranging from rent control to constitutional amendments allowing state officials more than one term.

The most controversial issue on the statewide ballot in Texas is a proposed constitutional amendment that would dedicate one-half of future state surpluses to a water fund that would be used to finance water projects.

Farmers in the Texas Panhandle are rapidly depleting the Ogallala aquifer, and Houston's water supply is dwindling. Many smaller cities in the state need guaranteed water resources to continue the rapid growth they have experienced in the last 10 years.

The water trust fund is the brainchild of Texas House Speaker Billy Wayne Clayton, a west Texas farmer who depends on irrigation for his livelihood. He argues that even with a vast network of water projects in place, Texas may not be able to meet its water needs after 1990 and that it must prepare now for the future.

Opponents argue that the plan unthinkingly throws billions of dollars at the water problem. They say the state's water needs have been overestimated and argue that conservation of water is a more sensible solution than expensive--and so far unplanned--water projects.

In Austin, voters will decide whether to sell their share of the South Texas Nuclear Project, a four-city nuclear power plant that is years overdue and several billion dollars above its original budget. It will be the second such vote in 2 1/2 years. In the first vote, citizens narrowly decided to stay in the project.

The project would supply power to Austin, Houston, Corpus Christi and San Antonio. The original cost estimate was about $1 billion; today it is up to $4-4.8 billion. The plant is scheduled to come on line in late 1986, compared with an original target date of 1980.

In New Jersey, voters will decide today the fate of a ballot proposition to limit the state's claim to riparian rights, the rights to sole ownership of land currently or formerly covered by the ocean's average high tide. The state now can make claims on the basis of high-tide marks dating back to the 17th Century, when King Charles II chartered the land that is now New Jersey to the Duke of York.

The proposal, a state constitutional amendment, would give the state only one more year to make claims going back that far. Then it could make new claims on land washed by tides during the previous 40 years. Some observers believe the ballot item marks the beginning of a battle that eventually will spread to other Atlantic Seaboard states.

The amendment's strongest supporters are those whose titles to coastal property might be clouded by state riparian claims, including casinos and beachfront developers. Its opponents include outgoing Gov. Brendan T. Byrne, who has called the amendment a "land grab" that will serve only big coastal developers. He argues that the state has never used riparian rights to bilk small property owners.

Other ballot measures across the nation:

In Washington State, voters will decide whether citizens should play a direct role in setting budgets for nuclear power plants.

In Kentucky, a constitutional amendment on the ballot would allow state officials--including Gov. John Y. Brown--to succeed themselves for up to two terms in office.

In West Virginia, a $750 million highway construction bond issue is on the ballot, with the backing of Gov. Jay Rockefeller.

In Minneapolis, a city with a tight rental market, voters will decide whether or not to create a Rent Control Adjustment Board to set maximum rent increases.

In Ohio, a referendum will decide whether to allow private insurance companies to sell workers' compensation insurance to employes who now buy their coverage through a state-run system.