Montgomery County Executive Isiah Leggett . (Katherine Frey/The Washington Post)

At a news conference Tuesday, Leggett announced a proposal to spend $4.21 billion in capital funding over the next six years. Overall, the proposal would be $168 million, or 4.2 percent, more than the previous capital spending plan, which was proposed two years ago.

But Leggett proposed $1.36 billion in school construction funds, a 0.3 percent decrease over the previous plan. The county school board had requested $1.49 billion, or a nearly 10 percent increase.

Leggett is proposing seven school additions and the construction of two new elementary schools and a new middle school. But he is proposing delaying the modernization of most middle schools and all high schools.

Leggett said that the school board’s request for a 10 percent increase would have been unsustainable and that the school system is doing better than other departments, which are sustaining 7 percent or 8 percent cuts.

Leggett said school officials have given a “guarded” response to the proposed decrease. In a statement, Superintendent Joshua P. Starr said he understands that the county is in a tough fiscal situation.

“It’s a very difficult balancing act,” school board president Shirley Brandman said in an interview Tuesday. “But I have concerns about any delays.”

While schools may be taking a hit, other departments might see significant increases. For instance, Leggett has recommended the department of health and human services receive $59.4 million — more than triple the amount the department received in the last capital plan. The increase is because of a new health center on Dennis Avenue in Silver Spring and a new children’s resource center, which is currently located in Rockville.

Other new projects include a transit center for Montgomery Mall in Bethesda, a replacement for the 2nd District police station and long-awaited improvements to three roads in the Clarksburg area.

The county would pay two developers in Clarksburg $15 million starting in fiscal 2015 after they complete construction of the three roads. The county has agreed to own and maintain the roads afterward.

Leggett also expects the water and sewer rate for county residents to increase by up to 8.5 percent.

The increase in the capital spending plan owes partially to expected increases in stormwater management funds and in special taxes being paid by residents living near a proposed mixed-use development complex in White Flint. County officials added that a recent slowdown in some construction projects freed up money for the new plan.

In a memo, Leggett said he kept bond agencies in mind as he crafted the fiscal plan, because he wanted to preserve the county’s coveted Aaa bond rating.