ITEM:

INFORMATIONAL ITEMS/STAFF REPORTS

 

27.

QUARTERLY IRRIGATION PROGRAM AND RIPARIAN PROJECTS REPORT

 

Meeting Date:

July 18, 2005

Budgeted

N/A

 

From:

David A. Berger,

Program/

N/A

 

General Manager

Line Item No.:

 

Prepared By:

Thomas Christensen

Cost Estimate:

N/A

 

General Counsel Approval:  N/A

Committee Recommendation:  N/A

CEQA Compliance:  N/A

 

IRRIGATION OF RIPARIAN VEGETATION: The supplemental watering of riparian restoration plantings resumed in May of 2005 at eight Monterey Peninsula Water Management District (District) riparian habitat restoration sites.  The following irrigation systems were in use in May and June:  DeDampierre, Trail and Saddle, Scarlett, Begonia, Schulte South, Schulte Bridge, Schulte, and All Saints.

 

            Water Use in Acre-Feet (AF)

            January - March 2005   0.00 AF

            April - June 2005           1.59

            Year-to-date                  1.59 AF

 

MONITORING OF RIPARIAN VEGETATION:  During the months of May and June 2005, 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.

 

Current monitoring results for the 2005 monitoring season to date show that riparian vegetation is 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 27-A and 27-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 June 2005 are as follows:

 

            Monitoring Measurement                                        

 

            Dawn  leaf water potential  (See Exhibit 27-A for trends.)        

            Soil moisture (tensiometers)                                          

            Groundwater levels (monitoring wells)   (See Exhibit 27-B for trends.) 

            Groundwater pumping (production wells)                     

           

 

 

OTHER TASKS PERFORMED SINCE MARCH 2005 REPORT:

 

1.        Riparian Planting Update:  During the period April through June 2005, District staff (Lyons and Bekker) planted a total of 60 riparian trees in open areas at the DeDampierre and Red Rock Restoration Projects located along the Carmel River.  Riparian plantings provide valuable habitat for threatened species and protect property from eroding river flows.

 

2.        Annual Carmel River Inspections:  On April 5th and 6th 2005, District staff inspected the Carmel River from Camp Steffani (River Mile 15.5) to the Carmel River Lagoon (River Mile 0.0). Annual inspections help determine the scope of work for vegetation management activities typically conducted in the fall in preparation for high winter flows, and for addressing new erosion problems and riparian ordinance violations.

 

No large downed trees that could divert high flows and lead to bank erosion were observed at this time.  However, several areas had vegetation encroachment that could possibly create debris dams and divert flows into banks.  These areas will be addressed this fall.  In addition, several riparian ordinance violations were documented and staff plans to follow up with letters to property owners.  Additional spot checks will occur this spring to track changes and document conditions for permit requirements.

 

EXHIBITS

27-A    Average Dawn Leaf Water Potential

27-B    Depth to Groundwater

 

 

 

             

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