Lawsuit-happy neighbor issues

[Nedrick]

What is the name of your state (only U.S. law)? Iowa

Our neighbor sued us (as well as previous owner/contractor) nearly 9 years ago because our garage was built too high and caused rain run-off into their basement. We eventually settled by giving them an easement to the north (closest to them) 6 feet of our property "for the purpose of landscaping, enlarging the access to their basement, pouring concrete to carry water away from Grantee's house, including the right to add dirt for landscaping and to maintain said property and improvements...to protect their house from water damage."

As part of the easement, we also signed a release to "fully and finally release and discharge (our names) from any and all present or future liability or obligation of any kind or nature in connection with the design, construction, configuration or location of their driveway or garage, including how they affect the flow or drainage of water on certain real estate owned by the (neighbors).

Last year, we added a wrap-around porch to the side of our house (facing the neighbors) which agitated them and led them to send us a letter informing us about a possible infringement of our easement and water issues. After talking with our lawyer, we found they didn't have a leg to stand on. Now, they've got a huge grudge against us now and look for every opportunity to get on our nerves. They told us we couldn't place garbage (for take-away) on their parkway anymore, can't wheelbarrow yard waste on their side of our fence to a wooded area behind our house, had their lawyer send a letter about insuffucient access to their back yard because of our fence (which has been there for almost 5 years), etc., etc...

So, we're at the point where we're ready to move and our big concern is that if we move, they'll sue the new buyers because the release has our name specifically only it. (They never really took advantage of the easement and did anything effective to fix the water drainage issue.)

Should we be concerned?

Thanks in advance!