Meeting Date:

January 25, 2007





David A. Berger,




General Manager

Line Item No.:


Prepared By:

Thomas Christensen

Cost Estimate:



General Counsel Approval:  N/A

Committee Recommendation:  N/A

CEQA Compliance:  N/A


IRRIGATION OF RIPARIAN VEGETATION: The supplemental watering of riparian restoration plantings was conducted in 2006 during the months of May through November at eight Monterey Peninsula Water Management District (District) riparian habitat restoration sites.   The following irrigation systems were in use May through November: Trail and Saddle Club, Scarlett, Begonia, Schulte South, Schulte Bridge, Schulte, All Saints, and Valley Hills.  One additional site came online in September with the completion of an irrigation system at the emergency bank stabilization project at the Dow and Kenny properties.


            Irrigation Water Use in Acre-Feet (AF)      

(final end-of-year values)                             


            January - March 2006              0.00 AF

            April - June 2006                     1.36

            July - September 2006             3.26

            October - December 2006       0.72

            Year-to-date                            5.34 AF


MONITORING OF RIPARIAN VEGETATION:  During the months of May through October 2006, staff took weekly measurements of leaf water potential on target willow and cottonwood trees to provide an indication of plant water stress and corresponding soil moisture levels.  Four locations (Rancho Cañada, San Carlos, Valley Hills, and Schulte) are monitored twice a month for pre-dawn leaf water potential.  A total of 14 willows and 13 cottonwoods at these locations provide a data set of established and planted sample trees that are representative of trees in the Carmel River riparian corridor.  Soil moisture measurements are conducted at three of these sites (San Carlos, Valley Hills, and Schulte) using tensiometers.  Soil moisture values are measured at seven stations with 18-inch and 36-inch tensiometers in the soil column.   Combined with monthly readings from the District’s array of monitoring wells and pumping records for large-capacity Carmel Valley wells in the Cal-Am system, the District’s monitoring provides insight into the status of soil moisture through the riparian corridor.


Monitoring results for the 2006 monitoring season revealed that riparian vegetation was below threshold stress levels.  Willows are considered severely stressed when values are 7.5 bars and above, while cottonwoods are considered severely stressed when values are 10.0 bars and above.  The graphs in Exhibit 26-A and 26-B show impacts to water table elevations and riparian moisture stress in selected restoration sites in the lower Carmel Valley.


The types of monitoring measurements made during May through October 2006 are as follows:


            Monitoring Measurement                


            Dawn leaf water potential                                  (See Exhibit 26-A for trends.) 

            Soil moisture (tensiometers)                                         

            Groundwater levels (monitoring wells)   (See Exhibit 26-B for trends.) 

            Groundwater pumping (production wells)                     






1.         Vegetation Management along the Carmel River:  District staff (Christensen, Watters, Kenner, Bekker, and Lyons), along with the help of a California Conservation Corps crew, completed three weeks of successful “vegetation management” work along the Carmel River starting on September 25 and ending on October 13, 2006.  Vegetation was selectively removed from of seven critical areas with vegetation encroachment in the channel bottom.  These sites were chosen for their potential to direct high flows from the center of the channel toward the banks and potentially cause erosion and property damage.


2.         Integrated Regional Water Management Plan (IRWMP):  District staff (Christensen and Hampson) reviewed the draft IRWMP for the Carmel Bay, Monterey Peninsula, and Southern Monterey Bay planning region.  Areas that require future work include the prioritization process for projects that will be part of an implementation grant.  The District is currently coordinating a Technical Advisory Committee to resolve concerns with the prioritization process.  



26-A    Average Dawn Leaf Water Potential

26-B    Depth to Groundwater