COVID-19 viral activity at Katy-area wastewater monitoring sites reached "very high" levels as of Aug. 20, the highest classification on Harris County Public Health's surveillance dashboard, according to KHOU 11 reporting.

Countywide, the agency rated activity as "high," with Katy and Cypress among the areas showing the strongest signals. The elevated readings come just eight days after Katy ISD welcomed more than 90,000 students back to classrooms on Aug. 12 for the start of the 2026-27 school year.

Why wastewater tracking matters now

Individual COVID-19 cases are no longer a mandatory reportable disease in Texas. That leaves wastewater testing as the primary tool for tracking community spread in Harris County.

A Harris County Public Health spokesperson told KHOU 11 on Aug. 20, "COVID-19 individual cases are no longer a mandatory notifiable disease in Texas, so we are unable to provide a total number of recent cases in the timeframe you indicated."

HCPH collects samples from sites across the county and tests them for COVID-19, influenza and RSV. The agency said the current increase should be viewed as an indicator of community-level trends, not a count of individual infections.

One outbreak already reported

HCPH confirmed it received one reported COVID-19 outbreak on Aug. 6 at a facility in the southwestern quadrant of Harris County. The agency did not identify the facility. Outbreaks are still reportable under Texas law, even though individual cases are not.

Surveillance expanding

HCPH has not issued specific guidance directed at Katy-area residents or Katy ISD families in connection with the elevated readings. The agency said it continues to expand its wastewater surveillance program to cover more areas of Harris County.

The dashboard does not publicly explain what thresholds define "high" versus "very high" classifications.