HOA flooded my basement and won't pay for repairs

So, I live in a condo association, where there are about 25% townhouses, and half of those have basements. I am one of them. Came home from work one day 6-7 weeks ago, went into the basement, and there is an inch + of water in there. Called my insurance agent, he got a water extraction company out to us quickly. Spent the next 2 days removing all personal items from the basement and into the garage. We also started immediately attempting to figure out where the water was coming from:

1. Sewer backup from full bath in basement...nope, plumber verified, plus the water seemed clean and had no smell.

2. Plumbing leak...turned off main water valve for 24 hours, nope, water still coming in.

3. Property manager thinks it is from "all the rain and the water table"...but it hadn't rained at all in over a week and there was no issue when it was raining.

4. Neighbor behind my unit says he and another neighbor could hear water running inside the retaining wall 20 yards up a small hill from my unit.

Call the Property manager, tell them there is a broken irrigation line. They send someone out to fix this, and now there is NO more water coming in and my sump pump is no longer running 24/7! My homeowners insurance won't cover outside water intrusion into the home unless you have flood insurance. When I ask for my costs for repair to be covered by the HOA, I'm told they don't cover inside damages, that this is on the homeowner...and when I say they should submit an insurance claim for it I am told that the homeowner is liable for their $50K deductible??!!

I attended the next board meeting and was given the same lame excuses for them to NOT cover my costs even though all parties are in agreement as to the reason for the water intrusion being their responsibility. They even had the gall to charge back their water extraction company's bill to me on my next monthly dues. All in all, we are out of pocket for $7800 in services and repairs. Spoke to a real estate lawyer this week, and odds are not great that a lawsuit would recoup my costs and legal fees, so there is little potential for a positive ROI on taking that route.