The Calgary Board of Education says masks will need to be worn by kindergarten to Grade 12 students and staff when classes resume in September.
The CBE said the decision was made after taking into account increased COVID-19 cases and the lower vaccination rates for youth ages 12 to 19 in the city.
The decision will be reviewed before the end of September, and the CBE said it will consider any further direction from the province's chief medical officer of health, Alberta Education, and active case counts in the Calgary area.
"We all play a role to ensure our return to school is as safe as possible and that we minimize the spread of COVID-19 in our schools and workplaces. The CBE has and will continue to encourage all eligible employees to get vaccinated," chief superintendent Christopher Usih said in an email sent to parents on Wednesday.
Other health measures will include:
Requiring students and staff to use a daily checklist to identify if they should attend school or stay home.
Staying home when symptomatic.
Practising proper hand hygiene.
Enhancing cleaning and ventilation.
Implementing classroom cohorts for kindergarten to Grade 6.
Not allowing unscheduled visitors or volunteers.
Limiting public use or rentals of school facilities outside of school hours.
However, the CBE said schools will no longer inform close contacts of positive cases, at the direction of the chief medical officer of health, but that additional health measures might be implemented if the COVID-19 situation worsens or if outbreaks occur.
The CBE is also lifting some health restrictions, such as allowing band and sports activities to go forward, as well as some field trips.
Last week, dozens of parents marched to the CBE's headquarters to call for stricter health guidelines in schools this fall. The provincial government hasn't mandated health measures for schools, leaving it up to local boards to do so.
The Calgary Catholic School District hasn't officially released its plan for COVID precautions for the 2021-22 school year, but superintendent Bryan Szumlas has said to expect similar measures to last year.
There are more than 5,600 active cases of COVID-19 across Alberta, and more than 2,000 of which are in Calgary.
Just over 23 per cent of all cases in the province have been Albertans younger than 19.
Around 56 per cent of those ages 12 to 19 have received two doses of a COVID vaccine. Children younger than 12 are not eligible to be vaccinated.
Registration has already closed for CBE's online learning program.
Post-secondaries in the city, including the University of Calgary and SAIT, are also requiring masks for back-to-school in indoor public areas where distancing can't be observed.