There are many old people and many families with young children living here.

这里是there be句型后面的独立结构的典型用法.
这个句子中已经有了谓语are,其实是一个倒装句,真正的主语是many old people and many families with young children,一个简单句中不能有两个谓语存在,所以必须处理成非谓语形式.