Centipede - low spots

This is what Dan Gill, retired consumer horticulturist with the LSU AgCenter, suggests/recommends in regards to filling low spots in the lawn - I assure you Dan is an extremely knowledgble and highly respected extension horticulturist. You are likely to get additional settling in the trenched area over the winter so it might be best to wait until spring. LINK.

If you use masonry sand as fill you will absolutely avoid potential contamination by torpedo grass - personally, I’d be extremely cautious of using river silt/pumped sand acquired from river systems in southeast LA as fill for this reason alone.

Bulk dirt or river silt carry really high risks of a host of weeds. Bagged soil may be weed free, but most brands are little more than finely ground mulch and will compact in a couple of years.

Possible alternative is to top low areas with clean sand then till into existing soil... then more sand to create volume you need. If you do it now, it will settle by the time grass starts growing again. Sow some annual clover in the patches to keep it pretty in the winter.