An estimated one million gallons of sanitary sewer water has overflowed, some of which has flowed into White Rock Creek, the city of Plano said in a news release Thursday morning. The overflow occurred at 5510 W. Plano Parkway Wednesday morning and ended early Thursday morning, the news release said. Drinking water will not be affected by the overflow, according to the news release. The Plano Public Works department has monitored the overflow and will perform cleanup in the affected areas. Heavy rainfall and winter weather throughout North Texas this week has caused the National Weather Service to issue multiple weather advisories for the region, including a flood warning for Collin County, which is expected to expire early Friday morning. The city of Frisco has also experienced about two million gallons of sewer water overflow—some of which poured into Stewart Creek. Drinking water remains safe for Frisco residents as well, according to the city.