Storm runoff in a concrete channel overflowed and eroded the footing for the service road circling Lake Murray reservoir near the San Carlos Bay portion of the lake. The channel funnels runoff into two large pipes going under the road and apparently excess runoff that the pipes couldn’t handle flowed over the top and undermined the soil beneath the road. Possibly the pipes were leaking as well. Crews put up barriers and it appears they have already done some excavation, probably to determine the extent of damage before repairs begin.

Arian Collins, Supervising Public Information Officer for the Public Utilities Department responded to my questions with this statement: “There was some damage to the roadway due to the recent rain storms, and the road has been closed to through traffic. Staff will be inspecting the area this week to determine the amount of damage and scheduling repair. At this time, it may take up to a month before the roadway is repaired. Since this is City property, any repairs will be paid for by the City.”

Click pics for enlargement:

Point at which runoff from channel normally enters the pipes but was blocked and ran over the top (I'm standing on the right side of the road shown in the next photo) Crews dug a roadcut to expose corroded pipes

The lake level is quite high but the ducks don't seem to mind

Update Jan 29: crews are working to build a temporary road bypass to allow through traffic until the repair project can be designed, funded, and approved. The crew supervisor told me that the two old deteriorated 48″ pipes under the road had plugged up during the storm, causing the heavy flow coming down the channel to spill over the road. He said the replacement pipes will probably be 60″ each. He also said since the damage is on Water Department property, expenses will be paid from water department funds, not from city taxpayer accounts.

Update Feb 8: the temporary repair is in place. Work on the permanent repair is expected to begin sometime in May. City Councilmember Marti Emerald wasted no time using this event for political advantage. On Feb. 3, she issued a press release headlined “Councilmember Marti Emerald Gets Fix For Lake Murray Sinkhole” (http://www.sandiego.gov/citycouncil/cd7/pdf/100203lakemurraysinkhole.pdf). Quite disingenuous, because the Water Department had already begun temporary repairs and planning for the permanent repair and provided Ms. Emerald’s office with information about it when she made her request. The press release also calls it a pedestrian path, but it is actually a service road belonging to the Water Department which the public is presently permitted to use.