Response from the City of Raleigh's Parks & Recreation Department:

Staff cleaned mud and silt from this location middle of last week and again on Friday after rains Thursday evening. Also reinstalled “dismount bicycle before entering tunnel” sign on the east side of the under pass. This location floods frequently after rain events. Staff will inspect and clean as soon as possible following future minor flooding. We generally send out PSA if clean-up is delayed due to magnitude and/or number of facilities impacted to warn citizens of wet/slippery conditions.