Title
Amendment No. 2 of Personal Services Agreement (PS 17-001) with Geotechnical Resources, Inc., to Provide Geotechnical Services for Mitigation Recommendations and Monitoring related to Trillium Park Drive Landslide
Body
RECOMMENDED ACTION (Motion):
Approve Amendment No. 2 of Personal Services Agreement (PS 17-001) between the City and Geotechnical Resources, Inc., to provide geotechnical services for mitigation recommendations and monitoring related to Trillium Park Drive Landslide
BACKGROUND:
Following a period of prolonged, intense precipitation in February 2017, there was land movement in the area of a deep seated landslide in Trillium Park Drive near Canyon Court. On February 16, 2017, the City’s water line pulled apart and damage occurred to the asphalt pavement in Trillium Park Drive. The water line was capped off and abandoned through the landslide area and a section of Trillium Park Drive was closed from Canyon Court to Swordfern Court.
On March 13, 2017, the City executed a personal services agreement with Geotechnical Resources, Inc. (GRI) to provide geotechnical services to monitor, evaluate surface conditions, make preliminary findings concerning the slope stability hazards at the site and develop recommendations to assist the City with short- and long-term mitigation options of the landslide with respect to public improvements. As a result of GRI’s initial landslide evaluation and recommendations, on May 3, 2017, the City executed Amendment No. 1 to install three inclinometers with piezometers to assist with the long-term monitoring of the public infrastructure within the City’s rights-of-way. For reference purposes, an inclinometer measures magnitude, rate and direction of landslide movement and piezometer measures ground water level. GRI’s initial evaluation included the determination that the landslide responds to high ground water levels in the area.
This Amendment No. 2 is for a fourth inclinometer with piezometer. After GRI provided their draft findings, evaluation of the landslide, and long-term monitoring recommendation, it was determined that a fourth inclinometer with piezometer would provide a long-term benefit for monitoring the public infrastructure in Swordfern Court.
The proposed four inclinometers with piezometers will be located in the following four approximate locations:
• In Canyon Court near property at 13776 Canyon Court (Amendment No. 1)
• In Trillium Park Drive midway between Canyon Court and property at 17346 Trillium Park Drive (Amendment No. 1)
• In Swordfern Court near the end of the cul-de-sac (Amendment No. 2)
• In Wake Robin Circle near property at 17405 Wake Robin Circle (Amendment No. 1)
BUDGET IMPACT:
Amount: $12,875 Amendment No. 2
FY(s): 2016-17
Funding Source:
25% Water Fund 510-551-6006
25% Street Fund 260-526-6006
25% Sewer Fund 520-552-6006
25% Storm Fund 530-553-6006