Complex sentence: The creek then travels in a northwestwardly direction through Regina, where it was dammed by the Canadian Pacific Railway to create Wascana Lake, both to supply water for steam locomotives and to create a decorative image in Regina.
Split into simpler sentences: The creek then travels in a northwestwardly direction through Regina. The Creek was dammed by Canadian Pacific Railway which created Wascana Lake, to supply water for steam locomotives and to create a decorative image in Regina.