Thursday, August 16, 2012

Hetch Hechy Valley Restoration Plan on Ballot for November

Picture from SF PUC web site
The Hetch Hetchy Valley is a glacier-carved granite canyon located in Yosemite National Park. Though once described by John Muir as a smaller version of the Yosemite Valley it is currently dammed and used as a reservoir and hydroelectric generator by the City of San Francisco. After obtaining more than 15,000 signatures, a group whose ultimate goal is to restore the Hetch Hetchy Valley has put an initiative on November’s ballot. The initiative would require the city to create a new master plan for their water system based on draining the reservoir and returning Hetch Hetchy to the national park service.

The initiative requires that the water plan include water recycling, water reclamation, conservation, improved storm water capture and increased development, including recharge capability, of groundwater sources and replacing the hydropower from the loss of the dam with solar and wind renewable sources of power. In addition, the plan would have to develop other sources of water supply because all the studies cited on both sides of the argument indicate that the water supply will fall short.

The Hetch Hechy system consist of much more than the reservoir created by the O’Shaughnessy Dam. The system consists of Hetch Hechy Reservoir, Cherry Reservoir and Eleanor Reservoir a portion of the New Don Pedro Reservoir as well as other small surface reservoirs of various size and significance and five groundwater basins.  The stored water in the system is transported to the cities, towns and farms supplied by the system via the Hetch Hetchy Aqueduct, the California Aqueduct, the Delta Mendota Canal, the South Bay Aqueduct, and the Pacheco Tunnel. 
Taken from BAWSCA
Now developing a plan for removing O’Shaughnessy Dam to restore Hetch Hetchy Valley is on the ballot. While many will dismiss the idea as preposterous, enough studies have been done and computer models created that it is fairly certain that the idea is only extremely costly and will reduce somewhat the reliability of the water supply. Billions upon billions of dollars depending on how certain you want your water supply to be, and remember these are costs that would have to be borne by San Francisco water rate payers not the state taxpayers or national taxpayers.

First of all, the inescapable regulatory costs- these costs are certain. While O’Shaughnessy Dam has storage capacity of 360 thousand acre-feet (taf) and the Hetch Hetchy system stores 2,000 taf of water a year, its value is more than that modest amount of water storage. The O’Shaughnessy Dam and Hetch Hechy reservoir provides water storage, hydropower generation, and some flood control, but primarily its value is that water from O’Shaughnessy Dam has filtration avoidance status. Without O’Shaughnessy Dam, the San Francisco Public Utilities System, SFPUC, would have to build a water treatment plant for filtration. New York is currently completing the construction of a new filtration facility to treat the water from the Croton Water System. Though it was originally estimated to cost $950 million, to date its cost has been $2.8 billion. This would translate to a cost of $5-$6 billion to build a filtration plant for SFPUC. Then on top of the construction costs and interest payments, there are the operating costs. Estimates have ranged from $13 million (estimated in 2000) to $20 million annually.

In addition, to replace the storage various solutions have been suggested the most obvious one being increasing the height of the Don Pedro Reservoir to increase its storage. This would require a major construction project. I could find neither feasibility studies nor estimates on the costs associated with that project- the dam cost about $100 million in 1967. Would it cost five times, ten times to expand it now? There is very little recent dam expansion or building data to use to estimate the cost.  However, to effectively replace the Hetch Hetchy storage an inter-tie linking the New Don Pedro Reservoir to the Hetch Hetchy Aqueduct would be necessary to avoid releasing the water through the Delta (and we know how that works out). It would probably cost a couple of billion or more to take care of those two items.

The ballot measure calls for including water recycling, water reclamation, and improved storm water capture in the plan. The reason is there is virtually no other way to obtain enough water for the Bay Area without it. It should be noted that at some time in the future these water reuse strategies will be necessary if the population of the Bay Area continues to grow. There are 993 miles of combined sewers in San Francisco, which collect sanitary sewage from toilets and drains in apartments, homes, schools, offices and other businesses, and street runoff throughout the city. The Water Sustainability and Environmental Restoration Plan would require rebuilding the sewer system to separate the storm water system from the sanitary sewer system and improving the water treatment and recovery of the wastewater treatment plants in San Francisco.

The two major waste water treatment plants that serve the city of San Francisco are the Southeast Water Pollution Control Plant in Bayview built in 1950’s and the Oceanside Water Pollution Control Plant built in 1993. On a dry day the San Francisco combined sewage system treats about 80,000,000 gallons a day of sanitary sewage.   The San Francisco Wastewater Treatment plants are not designed to do any more than screen out trash, skim off scum and grease and use bacterial action to digest toilet paper and bio-solids. Pharmaceuticals, pesticides, hydrocarbons and anything else the residents can think to pour down the drain or dump into the storm drains will either clog the system or be released into the Bay or Ocean. If we are to reuse this water additional treatment would be necessary. Pharmaceuticals, pesticides and other chemicals pass through the system untreated at this time additional treatment and control would be necessary to reuse this water. The cost of these systems would be dependent on the level of treatment desired to drink that water. Washington DC is currently engaged in a plan to upgrade their Blue Plains Wastewater Treatment system that discharges to the Potomac their program is estimated to cost $7.8 billion.

CALVIN (CALifornia Value Integrated Network) is an economic-engineering optimization model of California’s inter-tied water management system. It was developed by Jenkins et al. at the University of California, Davis and has been used to make many of the estimates for feasibility for removal of the O’Shaughnessy Dam and restoration of the Hetch Hetchy valley. CALVIN uses 72 years of monthly historical data to represent future hydrology. They use data from water year 1922 to water year 1993. This period includes the droughts of, 1929-1934, 1976-1977, and 1987-1992, which were some of the worst on record. However, this period of time may not be representative of the severity and duration of droughts and what rainfall will look like in the next decades. Australia’s experience with drought duration last decade should have taught us that.  The driest year in the data was 1924 when the state average rainfall was only 10.50 inches, but in that year the San Francisco Bay region was drier than the rest of the state. The future might hold a worse or longer drought or a regional drought.

An important limitation with CALVIN is perfect foresight; CALVIN knows when the droughts are going to happen and how long the droughts will be. This allows the model to be proactive in preparation for droughts, reducing water scarcity and associated costs. In addition, the model assumes that unlimited amounts of water can be purchased from others (farmers) to make up any shortfall and that there exists a pipe linking the New Don Pedro Reservoir to the Hetch Hetchy Aquitard.

This ballot measure is for the development of the Water Sustainability and Environmental Restoration Plan. This plan has the potential to be forward looking and develop an integrated and robust design for the water and wastewater systems of the Bay Area for the next century. The cost of developing this plan is limited to 0.5% of funds previously authorized by voters for the Water System Improvement Program, WSIP. That translates to $23 million dollars of the $4.6 billion WSIP just to develop a plan that must be completed by November 2015 “in time for the San Francisco Board of Supervisors or a group of citizens to propose a charter amendment to be voted on at the November 2016 election, which if passed would authorize implementation of the plan.”

Even this ballot measure is a significant decision for the residents of San Francisco, and about much more than restoring the Hetch Hetchy Valley. This is a first step on the road towards rebuilding the entire, water storage, treatment and sewer system for the Bay Area  as well as replacing the hydroelectric power from O’Shaughnessy Dam with other (hopefully) renewable power. The full implementation of the plan could easily cost San Francisco rate payers $10-$20 billion for infrastructure. I assume that funds to restore the Hetch Hetchy Valley would come from donations or the federal park service. The $23 million that the ballot measure authorizes for the study may not be enough to develop a fully integrated and workable plan, for transport, sewers, water treatment, water recycling and power generation let alone hold the necessary public hearings and outreach in San Francisco.    

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