Students carrying backpacks filled with school supplies returned in droves to school on Wednesday, the first day of the 2009-10 school year.

So much so that about 70 students who live in the Canyon Oaks Elementary School area east of Highway 29 will attend Donaldson Way Elementary School, said Canyon Oaks Principal Maren Rocca Hunt Wednesday. As she directed traffic in the parking lot, Rocca Hunt said the K-5 school is starting the school year with 630 students.

“We are full,” she said.

None of the 70 students transferred to Donaldson Way Elementary School were able to return to Canyon Oaks Elementary as of Friday, according to the schools.

One reason for the high number of new students is that families are doubling up in many American Canyon homes, a sign of hard economic times, Rocca Hunt said. At the same time, she added, home construction continues on the east side of town.

Eight-year-old Vince Dionsio was among the students reassigned from Canyon Oaks to Donaldson Way Elementary School Wednesday.

His mother, Nina Dionisio, said the family moved to American Canyon in June, and that they were looking forward to sending Vince to the neighborhood campus. It was only on Wednesday that they found out he’ll be going to Donaldson Way Elementary, more than a mile away and on the other side of busy Highway 29.

“It’s OK,” said Nina, as she, her husband and Vince returned to their car to drive to Donaldson Way Elementary School Wednesday. “We’ll see.”

As the Dionisios left, other students and their parents headed toward the front gate and the beginning of life at Canyon Oaks Elementary School.

“I’m nervous because this is my first year here,” said 10-year-old Jose Prieto, a fifth-grader who recently moved from Sacramento. A younger brother will attend Donaldson Way because there was no room at Canyon Oaks Elementary School, his stepmother said.

“We’re hoping for a transfer sometime soon,” said Angelico Prieto, Jose’s stepmother, whose daughter, Angelina, 7, and a nephew, Jesse Prebble, 10, also attend Canyon Oaks Elementary School.

Nearby, Gurjot Bhatti, 7, a second-grader at Canyon Oaks, waited silently for the front gate to open with his mom, Upninder.

“(I’m) fine,” Gurjot said quietly as his mother carried a ream of copy paper for the school.

With budget cuts already affecting schools and more cuts to come later this year, Rocca Hunt expects to have to review her school budget every quarter.

She predicted Canyon Oaks may not be able to buy such items as new computer programs. “People will see it in the classroom,” Rocca Hunt said.

While in past years the students turned away from Canyon Oaks Elementary School were sent to either Donaldson Way or Napa Junction Elementary School, this year Donaldson Way will absorb the overflow by itself.

As of Friday, Donaldson Way Elementary School had about 570 K-5 students.

On Monday, Dee McFarland, principal at Napa Junction Elementary School, said she expected 450 students, including about 30 elementary school-age students with disabilities.

American Canyon Middle School is also expected to be full this year. As of Friday, the school had 872 students — about 50 more than last year.

“We’re bursting at the seams,” Principal Dan Scudero said in his office Monday.