Look at these two photographs again.100 years separate them.
Above: Goodhue Ditch Headgate, 1909 and 2009. Historic photo courtesy of Carnegie Branch Library for Local History, Boulder CO.
During the last century, Gross Reservoir was built upstream. Large spring floods and sediment no longer came downstream. The creek eroded its channel deeper. The ditch company built a diversion dam because its headgate was suddenly above the creek level. Exotic species such as green ash and crack willow colonized South Boulder Creek. Taken all together, this explains why the creek is narrower now, and why there are so many more trees today.
Are you less fond of Boulder Creek, knowing that it is not "natural"?
Do you want the creek to return to its "natural" state?
What are you willing to give up to make that happen?