ITEM:		DISCUSSION ITEMS
2.	NEXT STEPS ON LOS PADRES DAM AND RESERVOIR LONG-TERM STRATEGIC AND SHORT-TERM TACTICAL PLAN
Meeting Date:			May 22, 2014	Budgeted:	No
From:			David J. Stoldt,	Program/
			General Manager	Line Item No.:
Prepared By:			David J. Stoldt	Cost Estimate:	See Below
General Counsel Approval: N/A
Committee Recommendation:
CEQA Compliance: N/A

SUMMARY: Staff has not concluded its review of the final Long-Term Strategic and Short-Term Tactical Plan for Los Padres Dam. Hence, the report is not ready for recommendation to the Board for acceptance, which will occur at a future Board meeting.

Staff has determined that removal or maintenance of Los Padres Dam includes more concerns than NMFS and Cal-Am have focused on (i.e., steelhead passage improvements, access to upper watershed spawning and rearing habitat, water supply, and water rights). Other issues include how the presence or absence of the dam affects water and sediment flows at the MPWMD’s Sleepy Hollow Steelhead Rearing Facility, effects on juvenile rearing habitat downstream of Los Padres Dam, sediment delivery to the downstream reaches and Carmel River State Beach, geomorphology of the river channel, and 100-year flood elevations. In addition, the potential effect of climate change on the long-term hydrologic cycle and runoff from the basin needs to be taken into account in the decision about this dam.

However, Robert Shibatani was asked to provide very rough estimates of potential scope of services that might continue to advance work on alternatives related to Los Padres Dam. The following represent a very preliminary evaluation of next steps as provided by Mr. Shibatani:

Scope A – In-Depth Alternatives Identification and Fatal Flaw Screening

-current alternatives; new alternatives; application of screening criteria specific to environmental issues, permitting, yield potential; land use/institutional, seismicity/geotechnical, constructability, project costs.

Time: 3 months

Estimate: $70-90K

Scope B – LPD Decommissioning Plan

-structural decommissioning, staging/phasing, riparian mitigation, post-removal stream design options, interim water supply provisions, interim instream flow objectives, interim sediment management, liaison with SWRCB/NMFS, phasing costs.

Time: 6-8 months

Estimate: $120-150K

Scope C – LPD Sediment Management Plan

-refined sediment budget, river profile sediment budget, removal options, sediment relocation options, by-pass options, baseflow continuance options, institutional issues, active management/removal staging, aquatic effects, flood aggradations, options costing.

Time: 3-4 months

Estimate: $60-100K

Scope D – Detailed Feasibility Studies of Top Three Off-Mainstem Storage Options from Long-Term Plan

-reconfirmed yield, storage capacities, diversion rights, raw water conveyance, sizing, institutional issues, land use issues, access issues, regulatory permitting, environmental fatal flaws, operational constraints, operational integration with existing water supply requirements, preliminary design and siting particulars, public outreach, State inter-agency liaison, private financing, project costs.

Time: 6-9 months

Estimate: $175-350K

Scope D – Hydropower and Pumped Storage Capabilities Study

-siting potential, operational range, operational constraints, power marketing, revenue analysis, licensing requirements, preliminary design considerations, project costs.

Time: 2-3 months

Estimate: $30-60K

Scope E – Regulatory Agency Integration Plan with New Peninsula Water Direction

-redefined watershed priorities, integration with MPWSP, strategy to maximize SWRCB support, strategy to maximize NMFS support, integration with Cal-Am options, develop proposed long-term regulatory solution for Carmel River (accepting pendency of IFIM study).

Time: 1 month

Estimate: $15-25K

In order to evaluate the options for Los Padres Dam, MPWMD has begun a comprehensive set of efforts to guide decision-makers. These include the April 2014 study entitled “Los Padres Dam and Reservoir Long Term Strategic and Short-Term Tactical Plan” by the Shibatani Group (referred to hereafter as the Shibatani Report), a scope of work to update instream flow recommendations using the Instream Flow Incremental Method (IFIM)^[1], and a hydrologic simulation of surface-groundwater interactions in the watershed using GSFLOW. MPWMD has also submitted a proposal to the Bureau of Reclamation WaterSMART program for a basin study of the Carmel River watershed that, if funded, would evaluate present supplies and demands and propose adaptation strategies for future hydrologic changes due to climate forcing. The basin study would evaluate climate change and sea level rise effects through the end of the century.

Hydrologic simulation model and revised instream flow recommendations are needed first in order to evaluate options for Los Padres Dam. What happens with Los Padres Dam and Reservoir could have significant effects on main stem flows during the dry season (typically June 1 through November 1), when juvenile and young-of-the-year steelhead are often at risk due to water diversions. Removal of the dam would reduce streamflow and juvenile rearing habitat in the dry season. On the other hand, maintaining or increasing the volume of surface storage – especially in the upper watershed – could provide a significant increase in juvenile rearing habitat over existing conditions when coupled with Cal-Am’s proposed future operations in the Carmel River after new water supply projects are completed.^[2] However, the effects on the quantity of steelhead habitat with and without surface storage have not been quantified. A GSFLOW ^[3] model can be used to compare how surface and groundwater supplies would be affected by the presence or absence of surface storage and changes in water supply operations.

A key component of determining water availability for municipal supply is the set of instream flow requirements necessary to maintain steelhead habitat during different life stages. The 2002 NMFS instream flow recommendations for the Carmel River are outdated and are based on habitat conditions that have changed significantly, especially in the lower 15.5 miles of the river. MPWMD recommends using the IFIM and incorporating 1-D and 2-D flow modeling in order to develop an updated set of instream flows needed to protect steelhead habitat between the Carmel River lagoon and Los Padres Dam. A GSFLOW model using an updated set of instream flow requirements would allow analysis of the effects of various alternatives on the availability of flow for steelhead and for municipal use.

Other studies for a dam removal option would include a sediment transport model combined with a flood study that should be carried out for the downstream reaches that could be affected in order to evaluate the effect of restoring the natural rate of sediment flow on channel geomorphology and 100-year flood elevations downstream of Los Padres Dam.

For an alternative that involves dredging of Los Padres Reservoir to recover storage capacity, MPWMD should take the lead in development of a project for permanent steelhead passage facilities and in studying alternatives for a long-term sustainable sediment management program. The latter effort would involve evaluating feasible options to bypass the natural sediment load in the river around the reservoir and would require a determination of the potential downstream effects from restoring the natural sediment load. MPWMD does not have a cost estimate for such studies at this time.

RECOMMENDATION: The Shibatani Report concludes that a hybrid alternative consisting of both the removal of Los Padres Dam and new off-mainstem storage development was determined to best meet the long-term needs of water supply, instream flows, and fish passage within the watershed and represented the most effective means of maximizing beneficial use of the basin’s available hydrology.

However, there has not been sufficient study to determine the effects of the various project alternatives on the river. The General Manager recommends deferring additional work on the Shibatani preferred alternative and instead undertake the studies already underway.

An instream flow study is estimated to cost up to $500,000 and would take two years to complete with a tentative start date in the Fall of 2014; however, MPWMD is seeking the cooperation of other agencies interested in an update of instream flows, which could substantially reduce the cost of this study. MPWMD estimates that development of a GSFLOW model will cost approximately $125,000 and should be completed by the end of 2015. This will allow MPWMD to model various future runoff and operations scenarios including river flows with and without main stem storage (Los Padres Dam), the effect of off-stream storage (e.g. Shibatani preferred alternative), and the effects of proposed future Cal-Am pumping scenarios.

U:\staff\Board_Committees\WSP\2014\20140522\02\item2.docx

---

[1] The Instream Flow Incremental Method (IFIM) is an interdisciplinary problem-solving tool – a modular decision-support system designed to help natural resource managers and their constituencies determine the benefits or consequences of different water management alternatives. MPWMD has developed a scope of work titled “Draft Carmel River Instream Flow Study Scope of Work,” dated February 6, 2014.

[2] Cal-Am proposes to reduce dry season diversions from the Carmel River to about 600 acre-feet between June 1 and November 30.

[3] GSFLOW is a simulation model developed by the U.S. Geological Survey that integrates a precipitation runoff model with a groundwater flow model to simulate flows throughout the area of study. The model allows simulations of changes in climate variables, surface storage, and groundwater development and returns information on surface and groundwater flow availability.