8. QUARTERLY IRRIGATION PROGRAM AND RIPARIAN PROJECTS REPORT
Program/Line Item No.: N/A
Staff Contact: Thomas Christensen Cost Estimate: N/A
General Counsel Approval: N/A
Committee Recommendation: N/A
IRRIGATION OF RIPARIAN VEGETATION: The supplemental watering of riparian restoration plantings in calendar year 2003 began in May at nine Monterey Peninsula Water Management District (District) riparian habitat restoration sites and is continuing in October. The following irrigation systems are in operation: DeDampierre, Trail and Saddle, Scarlett, Begonia, Schulte South, Schulte Bridge, Schulte, All Saints, and Valley Hills. Quarterly use for the year to date is as follows:
Water Use in Acre-Feet (AF)
April - June 2003 0.88
MONITORING OF RIPARIAN VEGETATION: During the months of May through September 2003, staff took weekly measurements of dawn 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 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 installed 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 2003 monitoring season show that non-irrigated sample willows at Valley Hills are severely stressed and cottonwoods are below threshold values. Sample trees are not irrigated intentionally to see how they respond in a natural setting with groundwater extraction. However, the projects as a whole are irrigated and riparian vegetation is under threshold values. 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 8-A show impacts to water table elevations and riparian moisture stress in selected restoration sites in Lower Carmel Valley. As of August 4, 2003 stream flow ceased in the Rancho Cañada area.
The types of monitoring measurements made during May through September 2003 are as follows:
Dawn leaf water potential (See Exhibit 8-A for trends.)
Soil moisture (tensiometers)
Groundwater levels (monitoring wells) (See Exhibit 8-B for trends.)
Groundwater pumping (production wells)
OTHER TASKS PERFORMED SINCE JUNE’S 2003 REPORT:
1. Quarterly Monitoring Report: District staff prepared the riparian monitoring section for the Quarterly Monitoring Report associated with the Conservation Agreement Monitoring Plan. This report addresses the increased pumping rate at Cal-Am's Rancho Canada Well.
2. Lagoon Vegetation Monitoring: District staff completed the annual survey of species composition and distribution at Carmel River Lagoon Wetlands. In addition to vegetation data gathered from line-intercept transects and quadrats, staff also measured ground water elevations from piezometers and collected soil samples for analysis of conductivity.
3. Meeting with Carmel River Watershed Council (CRWC): On July 30, 2003, District staff (Farina, Dettman, Christensen, Chaney, and Hampson) met with CRWC representatives to discuss CRWC's request for District assistance with the CRWC's Watershed Assessment for the Carmel River. The General Manager indicated that the District looks forward to a collaborative effort with CRWC request. Professional services will be compensated but staff will also be volunteering time outside of work hours. The District has already provided many original documents of interest to the CRWC.
4. Irrigation System at Cal-Am's Rancho Cañada Well: On August 12, 2003, District staff (Christensen and Bekker) assisted Cal-Am and Monterey Peninsula Engineers in set-up of the irrigation system on the south bank of the Carmel River opposite Cal-Am's Cañada Well. This system is designed to offset impacts to riparian vegetation associated with an increase in pumping capacity of the well from approximately 1,500 gallons per minute (gpm) to 2,500 gpm. Rancho Cañada Golf Club is currently irrigating the north side of the river in the vicinity of the well.
5. Assistance to Carmel River Watershed Conservancy: District staff (Christensen and Hampson) met with representatives of the Carmel River Watershed Conservancy (CRWC) on September 3, 2003 to assist the CRWC with preparations for a workshop on using the "Properly Functioning Conditions" (PFC) method to assess the health of streams within the Carmel River watershed. This method was chosen by CRWC to be consistent with efforts in other watershed assessments throughout California and consists of a checklist-type approach to assessing the condition of streambanks, channels, and streamside vegetation. The workshop has been tentatively scheduled for October 11, 2003 and will be targeted toward property owners, land managers, and persons interested in helping to assess the Carmel River watershed. CRWC is seeking representatives from all main Carmel River tributaries and selected sub-basins for this workshop.
6. Annual River Clean Up: On September 10, 2003, District staff (Christensen, Bekker, Lyons, and Summers) began the annual river clean up from the Highway One Bridge to just upstream of Rancho San Carlos Bridge. To date, eight tires, various car parts, and a large quantity of household trash have been removed from the riverbed.