The Beaver Wave is a great low flow option in the Denver area. At prime flows it forms a great A-shaped wave with a solid right shoulder, and at higher flows it forms a significant left shoulder as well. Most flows produce a solid wave from knee to waist high that can be surfed with a pretty wide variety of craft. As of summer 2016, access is sometimes hampered by construction on the South Platte Trail, but if worse comes to worse you can hike up the banks or even the riverbed from Habitat Park.
Fall flat here; the rocks are pretty close, especially at lower flows, and out of control falls off of the wave can lead to injuries. There are also a few rocks guarding the eddies on both sides; be sure to check out the shallow rock on surfer’s right along the eddy line before you drop in for your first ride.
At low flows, bring something with volume like a SUP (e.g. the IRS) or the Taquito. As flows get over 180-200 or so, I’ve had a lot of fun on the CBC Fish. Shorter custom-built riverboards also work well at higher flows too.
The South Platte at Englewood gives the best gauge information here; the wave is surfable with a long enough/high enough volume board starting at about 120 cfs if you’re desperate, but you really want 140 cfs or more.
Park in the Habitat Park lot and cross the river where you can depending on construction activity; the wave is about 300 yards upstream from your parking space.