Tom Butt
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  Seacliff Slide Update Saturday January 7, 2023
January 6, 2023

From City Manager Shasa Curl:

Evacuation Orders

Fifteen (15) homes within the impacted area have been evacuated and are unoccupied.  Per the City’s consultant, Cal Engineering & Geology, Inc. (CE&G), there is currently no need to evacuate additional homes. In addition, CE&G recommends that the evacuation orders of the fifteen (15) homes remain in effect until further notice. 

City staff contacted evacuated residents on January 6, and provided a brief status update and shared that the City would provide relocation accommodations through at least January 9, with the possibility of an extension dependent upon additional geological assessment or reports and continued site assessments (see attachment). In addition, due to this extended evacuation period, residents were notified this evening and are provided an opportunity to access their homes to obtain essential items.  This limited access is being coordinated with Richmond Fire and Police personnel on site to ensure maximum public safety.

Site Assessment and Mitigation Efforts

On January 4, representatives from the Seacliff Homeowners’ Association (Association) notified the City that they would take over the identification and implementation of mitigation.

At 8:30 AM on January 5, the City’s contractor WR Forde provided Rick Willis, president of the Association, with access to the staging area at the top of the hill via East Bay Regional Park District property.  The contractor showed Mr. Willis the location of the sandbags, plastic sheeting, stakes, and other materials procured by the City for the tarping effort.  By 9:00 AM, WR Forde demobilized from the site.

The Association retained Engineered Soils Repair, Inc., as well as Kropp and Associates, to assess the site conditions and to implement temporary stabilization measures.  Their crews commenced installing plastic sheeting on the hillside on Thursday, January 5.  Weather permitting, crews will work Friday, Saturday, and potentially Sunday.  Based on preliminary discussions, the City understands the Association plans to cover the entire landslide area in plastic sheeting and install temporary pipes on top of the slope to divert runoff from the existing underground system.  The City plans to coordinate with the Association and monitor the work.

In addition, CE&G has identified and informed the City of a depression in the Seacliff Drive roadway, in the left turn pocket at Seaview Drive. Public Works has installed barriers to prevent access to this portion of roadway. Veolia inspected the underground piping in this location and did not identify any dislocations in the pipe.   CE&G’s report does identify the location of the depression and additional investigations are being done to identify potential causes and remedies.

City of Richmond Public Works and safety (Police and Fire) personnel continue to staff the incident area to limit unauthorized access, secure property, and monitor mitigation efforts.

Proclamation of a Local Emergency

During a special meeting of the City Council on Monday, January 9, the City Manager is requesting the adoption of a resolution ratifying the proclamation of a local emergency in the City of Richmond made on January 3, 2023, due to a large landslide on a hillside, east of Seaview Drive, that forced the evacuation of fifteen (15) homes in the impacted area.

The Director of Emergency Services (the City Manager) may request the City Council to proclaim the existence or threatened existence of a "local emergency” if the City Council is in session, or to issue such proclamation if the City Council is not in session. Whenever a local emergency is proclaimed by the Director, the City Council shall take action to ratify the proclamation within seven days thereafter or the proclamation shall have no further force or effect [Richmond Municipal Code Section 2.20.060]. The proposed resolution will approve the proclamation of the emergency order so that it can remain in effect until City Council rescinds the order.

Street Closures Updates

Only portions of Seaview Drive and Seacliff Way are closed.  Seacliff Drive remains open to through traffic.  See diagrams of road closures below.
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Below please find the update regarding the COR Waste Water Treatment Plan (WWTP) Rockslide Incident.

A rockslide occurred at the WWTP site on or before 7:30 AM on January 4, 2023, due to the recent storm events.  The aftermath of the rockslide was observed by Michael McKenzie an employee of Veolia.  The rockslide damaged the security fence on the backside of the Waste Water Treatment Plant (WWTP). A consulting geologist was asked to perform a site visit to survey the situation.

The aforementioned geologist from the consulting firm Questa, Will Hopkins, again walked the plant fence line the morning of January 6, 2023, assessing the City’s potential risk for further damage to the fencing and to adjacent assets. Based upon the rocks that have already crashed through the fencing and in accordance with Mr. Hopkin’s recommendation, staff had the contractor (i.e. Meyers) bring 120 feet of K-rail to the site. The K-rail is being strategically placed between the fencing and the West County effluent manifold at the confluence structure. At the moment, the above ground effluent manifold presents the highest potential for damage due to location and physical exposure. The geologist will return early next week following the storm event that's forecast for the weekend to follow-up on conditions after the storm and determine if any further preventative actions are needed. Photos of K-Rail below:

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The following is an excerpt from the email report provided by Mr. Hopkins that further elaborates upon the incident’s evaluation:

“It was observed that the slope includes various locations where talus slopes of loose rock debris have blanketed the steep slopes above the Plant area.  These talus slopes are the ramps upon which the blocks of rock slide downslope.  Measurements indicate that many of these slopes are steeper than 45 degrees, making them inherently unstable.  Gravel and angular rock piles will stand on their own at a steepness of approximately 40-45 degrees.  When you exceed this steepness, the gravel will tend to raft downslope along the surface and can reach significant velocities.

The current weather conditions, periodic periods of rainfall with some of higher intensity, tend to dislodge soil and fines that fills voids and cracks in the exposed bedrock and on the soil/rock slopes, freeing the boulders and blocks of rock to move downslope.  The water also adds weight to soil/rock so that what was marginally stable under dry conditions is now unstable under wet conditions.

Several boulder size blocks of rock have fallen downslope damaging the perimeter fence and even penetrating through the fence.  We recommended to Veolia personnel that the perimeter fence needs to be reinforced to reduce the potential for boulder penetration.  It was suggested by Veolia personnel that a K- rail type concrete structure could be used to line the area behind the critical area of perimeter fence located near the WCWD structure and main outfall structure.  Veolia personnel instructed Myers and sons to procure 120 feet of K- rail to install as a temporary mitigation measure adjacent to the critical facilities.  The k-rails are en route and should be installed this afternoon.”

Below please find the update regarding 1169 Fairway Drive / Caltrans Drainage Incident.

Figure 1 Photo of Drainage Fissure

A fissure has appeared on Caltrans property in the vicinity of 1169 Fairway Drive. This fissure does not seem to be the result of any recent work but may be as a result of the increase runoff from this storm event.  Staff contacted Caltrans to discuss the situation.  The Caltrans representative reported that he was aware of the situation and has erected some temporary repairs.  He also later noted that Caltrans will construct permanent repairs at some point after the storms have passed.


This is the response from Dan Schnapp, Caltrans Area of Richmond Maintenance Supervisor, via text message at 4:45pm January 5, 2023:

“We are aware of the situation and have made some temp repairs that should help until the rains stop”

See photos below that depict the temporary repairs effected by Caltrans.

City of Richmond team members continue to work diligently to provide excellent customer service to our community.

Thank you,  

Shasa Curl
Richmond City Manager
Office: 510.620.6512