It's actually a concrete channel about 3-4 meters wide in the middle of this wide and falt waterway.   Cyclists including me typically ride the concrete under two bridges from the Behrens Ranch greenspace to the gravel trails on the north end of the waterway.  

You can see the concrete in a satellite view and use Strava's heatmap to see the traffic.  It's not a trail, per se, but it would be beneficial to those using Ride With GPS to create a route to be able to use this path.