South Platte Closed @ Santa Fe/Vanterbilt Park
So last night I did a longboat workout from Mineral up towards downtown. Where Santa Fe crosses the river between Mississippi and Alameda there is massive construction going on in the river for the new bridge for Santa Fe.
There are "River Closed Ahead" signs on the bridges at Mississippi and the one before that. In the river are 4 four-foot diameter concrete pipes completely submerged in the water with a concrete layer on top for construction vehicles to drive over. It is extremely dangerous for boaters as it isn't obvious until you are right on top of it and the current into those pipes is incredibly strong. We messed up and had a boat get pulled into one of the pipes folded in half (it later came out the other side but I wouldn't expect that to always be the case).
The river really should be considered closed there to all boating. At yesterday's water level we could have pulled over about 20 ft above the pipes on river right but with less water, I think the current would get quicker there and the eddy may disappear.
So if you are headed up that way, be sure to take out no later than the first boat chute after Mississippi. Overland Pond Park has been improved into a really nice takeout, so you should probably take out there instead (assuming you can get past any remaining construction fences, we didn't look too closely).
American Whitewater river info you can use.