HAVA, which Congress approved in 2002 in the wake of the Florida voting debacle, is best known for requiring a nationwide switch to electronic voting machines, but it also mandated that polling places be made more accessible to people with disabilities.
As a result, many old voting locations needed wheelchair ramps, more parking and wider doors to meet the standards. Sedgwick County's insight is that it's cheaper to just eliminate polling places that don't meet the specifications than to retrofit them so that they're up to snuff.
In fairness, Sedgwick County officials do say they will make it easier to vote prior to Election Day to compensate for the changes. And this isn't the first place that has cut down on polling places as a result of HAVA. Local officials in Great Falls, Montana, Ottawa County, Ohio and St. Joseph County, Indiana all cited the federal law while taking similar steps earlier this year. I haven't been able to find any data to show whether the number of polling places is decreasing nationwide, but I'd guess that's the trend, either as a result of HAVA or a switch to more early voting.
I'll leave it to you to decide whether the feds are getting their just comeuppance for an unfunded mandate or whether local officials are abrogating their responsibilities, although it's worth considering that those two interpretations might not be mutually exclusive.