Why isn't stormwater treated before it goes into a creek?

Some older sewer systems use a Combined Sewer System, which blends stormwater runoff with municipal sewage. Stormwater reaching the sewer system flows to a treatment plant and is treated along with sewage. There are serious risks with this system because combined sewers can handle only small rain events. Flash floods, which happen frequently in Texas, can quickly overwhelm this type of system, resulting in sanitary sewer overflows, which are messy, smelly and detrimental to lakes and streams. This can also be a health hazard since untreated sewage can transmit disease. 

To prevent this, the City of McKinney, like most cities in North Texas, uses a Municipal Separate Storm Sewer System, which separates stormwater from sewage and conveys stormwater runoff directly to creeks and lakes. This type of system vastly cuts down the risk of sanitary sewer overflows and directs stormwater as efficiently as possible out of our streets and away from homes and buildings. 

Learn more about separate storm sewer systems and why they are a better solution for stormwater than directing it to a treatment plant

Show All Answers

1. What is stormwater runoff?
2. Who regulates stormwater runoff?
3. Why all the fuss about stormwater?
4. Stormwater pollution only affects streams and creeks. Why should I care?
5. Into what water bodies does the stormwater from the McKinney storm system discharge?
6. Why is there a marker on our storm drains?
7. Where can I find McKinney’s requirements related to stormwater management?
8. Are there any charges or fees associated with the storm drain system?
9. Who clears clogged storm drains?
10. Why shouldn't yard trimmings and soil go into the storm drain? Doesn't rain wash the same kind of material into the creek anyway?
11. Why isn't stormwater treated before it goes into a creek?
12. What do I do if I see someone dumping something other than rainwater down a storm drain?
13. If I make a complaint, will my name and address be kept confidential?
14. There is mud on the street in my neighborhood. What can the city do about it?
15. There is erosion and poor drainage in the creek near my house. What can the city do about it?