Why does this surprise you? Since deficit spending is generally disallowed for state and local governments, nearly all sizable projects are funded through bonds. Bonds are basically loans with a promise to pay back in the future, generally with tax revenues. So you are paying off that 99 year bond to build a TB sanatorium built in the 1930s.

We are doing the same thing today. My grandchildren will be paying for the school repair and high-speed rail bonds that passed a couple of years ago here in California. Their grandchildren will be paying off the anti-global-warming school air conditioning and hyper mag-lev rail bonds that will be put forth 25 years from now.