1. Charles agreed to finish the report for his study group, but then discovered that the books he needed were only available in the library, and the library was closed. He was up the creek.
2. The city administrators expected to pay for street repairs from their existing budget but that money ran out when they had to pay for damages caused by unexpected storms. They were up the creek without a paddle.

Synonyms: high and dry; leave (someone) in the lurch. The expression suggests a situation where one is in a canoe on a small river without the means to navigate. It describes a situation in which one wants or needs to proceed but lacks the means.