"It's sad any time a permit system needs to be implemented, but it's time." 

The White River National Forest (CO) is the nation's most trafficked national forest, and Hanging Lake -- a National Natural Landmark -- receives an erosive amount of that traffic. After years of public overuse (an estimated 150,000 visitors hiked the trail to the lake in 2016), the White River National Forest has proposed a management plan to solve the issues caused by heavy recreational traffic. The proposal aims to implement new permits that will manage trail congestion and visitor experience, and protect and restore the natural state of the trail. 

Here's what MS Ambassador, and Master of Environmental Management, Mitch Warnick has to say on the matter:

It's sad any time a permit system needs to be implemented, but it's time. It is important to note that permit systems are a nightmare to manage and no agency actually wants to implement and enforce it, so any time there is a permit system it is because all other options have been exhausted.  There was also word of the FS (Forest Service) considering closing it to the public completely, so everyone who is 'upset' should count their blessings. 

In my opinion, perhaps simply closing the parking area could have been a good first step -- this would force people to put in that extra time and effort to simply get to the trailhead from elsewhere, naturally dissuading visitation (because a lot of people are lazy).  Furthermore, I think that there should be crushing fines in place for violations like littering, swimming in the lake, or bringing dogs -- I'm talking thousands of dollars.  When the people won't listen, money talks loud enough.