Maintenance and Repair: Who is Responsible for Sewer Repair if Their Tree It Breaks on Their Land

My question involves real estate located in the State of: Texas


Background:

• I own a house that's on the golf course
• The city sewer line runs through the golf course behind my house
• My sewer line connects to the city line about 6 ft beyond my back fence
• There is a 16 ft utility easement, 8 ft on my property and 8 ft on the golf course property.
• About 3 ft outside of my property (about halfway between my property line and the city sewer) there is a tree is on the golf course
• A root from that tree has broken my sewer line
• sdf

So my questions are:

1. Who has the responsibility to repair the line? Me, the golf course since THEIR tree broke my line on THEIR property, or the Utility company that holds the easement?
2. If it's my responsibility, do I need permission to make the repairs? If so, who do I need permission from? The golf course, or the Utility company?
3. Do I need permission/temporary construction license from the golf course? They are "requiring" I hire a 3rd party to complete the repairs and provide proof of $1m of liability insurance. They are also requiring I sign an indemnification
4. Or do I need permission from The utility company since the break happened within their easement? Are they the only ones who are allowed to make repairs within the easement?

I've scoured the internet, but my particular facts and circumstances aren't really addressed. I understand if their tree broke my line within my property boundary it would be my responsibility, but since it happened on their property, I think it's less clear. Any insight you can provide would be greatly appreciated!

I offered to pay for the actual plumbing repairs if the golf course would provide the digging. They have the labor and the equipment to accomplish that task in a very short amount of time. But their legal dept shot that down, which I guess I can kind of understand, given they are not "licensed" in this particular field.

We are now trying to sell our house, so I need to get this wrapped up. I am probably going to have to go ahead and pay for it up front, but I wanted to know if I need to sign this dang waiver and if I have any recourse to collect after I pay.

Maintenance and Repair: Who is Responsible for Sewer Repair if Their Tree It Breaks on Their Land