ITEM:

INFORMATIONAL ITEMS/STAFF REPORTS

 

26.

QUARTERLY CARMEL RIVER RIPARIAN CORRIDOR MANAGEMENT PROGRAM REPORT

 

Meeting Date:

January 30, 2013

Budgeted:

N/A

 

From:

Dave Stoldt,

Program/

N/A

 

General Manager

Line Item No.:

 

Prepared By:

Thomas Christensen and

Cost Estimate:

N/A

 

Larry Hampson

 

 

                            

General Counsel Review:  N/A

Committee Recommendation:  N/A

CEQA Compliance:  N/A

 

IRRIGATION OF RIPARIAN VEGETATION: The supplemental watering of riparian restoration plantings was carried out in 2012 at six Monterey Peninsula Water Management District (District) riparian habitat restoration sites.  The following irrigation systems were in use from April through October: deDampierre, Trail and Saddle Club, Begonia, Schulte, Valley Hills, and San Carlos at the Dow Property.  MPWMD uses a combination of drip and sprinkler systems, according to site conditions.  Since 1995, annual irrigation season totals have ranged from approximately 4.5 to 12 acre-feet per year. 

 

            Water Use in Acre-Feet (AF)

            (preliminary values subject to revision)

           

            January - March 2012             0.39 AF

            April - June 2012                    1.54

            July – September 2012            3.51

            October-December 2012         1.28

            Year-to-date                            6.72 AF

 

 

MONITORING OF RIPARIAN VEGETATION:   Beginning in May and continuing through October 2012, staff recorded bi-monthly observations of canopy vigor at target willow and cottonwood trees to provide an indication of plant water stress and corresponding soil moisture levels associated with groundwater extraction.  Monitoring is carried out bi-monthly at four locations (Rancho Cañada, San Carlos, Valley Hills, and Schulte).  Characteristics such as yellowing leaves and percentages of defoliation are used to rate the health of the canopy on a scale from one to eleven (see scale on Exhibit 26-A).  A total of 12 willows and 12 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 values are measured at all four sites using 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 California American Water service area, the District’s monitoring provides insight into the status of soil moisture along the riparian corridor.

 

Monitoring results for the 2012 monitoring season show that riparian vegetation starting showing  signs of stress in the late summer.  However, District irrigation systems and the onset of winter rains helped keep vegetation below threshold stress values in the vicinity of large-capacity wells. The graph in Exhibit 26-A shows average canopy ratings for willows and cottonwoods in selected restoration sites in the lower Carmel Valley.  The graph in Exhibit 26-B shows impacts to water table elevations.

 

The types of monitoring measurements made during May through October 2012 are as follows:

 

            Monitoring Measurement                                        

 

            Canopy ratings                                                (See Exhibit 26-A for trends.)          

            Soil moisture (tensiometers)                                       

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

            Groundwater pumping (production wells)

 

OTHER TASKS PERFORMED SINCE THE OCTOBER 2012 QUARTERLY REPORT:

 

Carmel River Vegetation Management: District staff completed “vegetation management” work along the Carmel River on October 31, 2012. Vegetation was selectively removed from three critical areas with vegetation encroachment in the channel bottom. A total of 478 square feet of stream was opened up. These sites were chosen to minimize the potential that high flows would be directed from the center of the channel toward the bank, possibly causing erosion and property damage.

 

Carmel River Advisory Committee: The committee met on October 25, 2012 for a field trip to the Schulte Road Bridge replacement site and to the lower Carmel River to see an example of bank erosion and to discuss solutions. In addition, the Carmel River Advisory Committee had its regular meeting on November 11, 2012. Minutes of the meetings are provided in the Carmel River Advisory Committee packets.

 

State Proposition 84 Integrated Regional Water Management (IRWM) Grant Program:  MPWMD and Denise Duffy and Associates conducted a second stakeholder meeting with 30 IRWM stakeholders on October 24, 2012.  The group revised the water management strategies to be included in the updated IRWM Plan.  During the fourth quarter of 2012, all nine planning projects and an update of the IRWM Plan had commenced.  As of October 1, 2012, 17% of grant funds ($167,170) had been expended.  The deadline to complete all work under the IRWM grant is December 31, 2013.

 

Sleepy Hollow Ford Removal and Bridge Replacement Project: A constructability analysis and draft final design for the bridge were completed.  The final design is due to be reviewed by California Department of Fish and Wildlife (CDFW – formerly the California Department of Fish and Game) representatives in January 2013.  However, MPWMD and CDFW have suspended additional work on this project until California American Water (Cal-Am) grants access for construction of a permanent bridge.  Cal-Am intends to use the Sleepy Hollow Ford site to place a seasonal temporary bridge to allow access for heavy construction vehicles for the San Clemente Dam Removal and Carmel River Reroute Project.  The San Clemente Dam Project is expected to be completed within three to four years.  After all construction activities associated with dam removal are complete, a permanent bridge at the site of the present-day Sleepy Hollow Ford would be erected.

 

Schulte Road Bridge Replacement Project: District staff met several times with Monterey County Public Works Department to discuss temporary and permanent measures to stabilize streambanks at the site after the first phase of construction was completed.   Temporary measures were put in place in areas where the second phase of the replacement project will occur, which is scheduled for the summer of 2013.  Permanent measures included placement of ½ to 1-ton rip-rap along the streambank and revegetation of disturbed areas with willows and cottonwoods.  MPWMD is cooperating with the County on an irrigation plan to supply water in the dry season to new plantings.

 

EXHIBITS

26-A    Average Willow and Cottonwood Canopy Rating

26-B    Depth to Groundwater

           

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