Sounds to me like the city got caught with their pants down and one hand in the federal cookie jar! Also sounds like there would be any number of ways to resolve this other than a simple ban on skydiving.
I wonder how many times the abuse is actually documented with time, date, N number of the airplane on takeoff, and the name of the abuser?
If you have it set up where people are crossing the runway after every load you will have the occasional head-up-ass from some newby all excited on adrenaline about some personal accomplishment he just achieved in freefall with his ears still plugged from the rapid descent, big deal. There are runway incursions all the time with aircraft, we don't ban flying.
Now if that is NOT the real reason for the ban then they'll need to come clean and then you get into the current issue about discrimination of a legitimate aeronautical use and the federal grant assurance rules.
I've been a part of many different jumping operations where jumpers had to cross a runway all with very few issues even at a 100,000 jump a year operation. I doubt that the Eugene Skydivers does anywhere near that volume so I see it as a manageable issue.
It's all back to a non-controlled airport see and avoid. Airplanes, cars, deer, jumpers in the air, jumpers on the ground, birds, etc.
Looking at Google this is how I see it, if that complaint is the real issue and not just masking small town BS.
1. Land all of the tandems, professionals, and "checked out" experienced jumpers on the west side between the highway and the hangars. That's about 750' x 200', plenty for a modern canopy with a competent pilot.
2. Buy an old pickup for $500 and build benches in the back bed, spray paint it yellow, put a yellow light on the top, and install a VHF radio tuned to unicom. Being careful to train the driver that not all airplanes have radios and some can break or that transient pilots can have their head-up-ass and be on the wrong freq. Then specific drivers with airport ground movement operations training could be used to operate the vehicle to pick up the students and less experienced jumpers from the east side of the runway and bring them back in a more visible, organized fashion at a designated point on the runway.
3. As part of the waiver process any visiting jumpers or students could be instructed to use the same designated crossing point or go around the ends no matter where they landed along the east side in the event that the truck was gone for some unforseen reason.
4. A small presentation could be presented to the local pilots one evening to advise them of the new procedures for the jumpers and to also just make them more aware to be on the look out for crossing jumpers.
5. A small note could be put at the bottom of a noise abatement sign at the runup area for transient pilots to do the same.
6. The operation could also train the jump pilots to increase their awareness and to assist in preventing crossing issues by making radio calls to other aircraft they may see pulling out on the runway while jumpers have just landed and are crossing (in the event of no truck) as soon as they come off of center and are entering the downwind making pattern calls anyway. If the jump pilot has his head on it would be really easy to see it all as he checks the windsock and scans the end of the runway for traffic entering the downwind.
I'll bet there might still be the occasional violator as there is in anything but I'd bet my career on the fact that the number of incidents per volume flown there would be next to none with those procedures in place. If a DZ that does 100,000 jumps a year can keep it to like two issues per year I think a small Cessna DZ in the fog and overcast of the Northwest could keep it to like .25 issues a year and that's pretty much just having to share the planet with other humans.
Now if this is some other small town politics crap under the guise of a runway incursion issue then I hope the FAA nails the city's ass to the wall and the city should be ashamed of even considering wasting tax payer money to stifle a legitimate aeronautical use over some personal fear. One that due to its nature of going point A to point A provides more cycles to justify an airports federal funding than any of the $400 weekend hamburger getter's and coffee crowd landing judges ever will.
I would think that in the time of increased fuel prices, aging pilot pool, high cost of learning, and the fenced out, video game young generation seemingly less interested to do something that doesn't include a couch and air conditioning a full service facility like that would really want an operation that was going to pull out one or two 182's on a sunny weekend and put 40 cycles of use on the FAA board for future funding justification and burn $1,250 worth of fuel. Not to mention providing possible maintenance work to the local shop, flight hours to the local struggling flight instructor or weekend pilot that doesn't have the disposable income due to the economy to put the fuel in his own airplane, and the fact that the jumpers will buy chips, sandwiches, and hotel rooms from the local businesses. But what do I know.