1 OVERVIEW
The Lake Don Pedro Community Services District (LDPCSD) has been continuously providing water to the community of Don Pedro since its development in the 1960’s. The community’s water supply is pumped from Merced Irrigation District’s (MID) Lake McClure through two fixed pumps, set at 700 feet above sea level on the shores of the Lake near Barrett Cove Marina. The LDPCSD also operates one groundwater well on Ranchito Dr. that is pumped to the water treatment plant on Merced Falls Rd. for treatment and distribution.
The water supply remaining in Lake McClure is extremely low; less than 7% of capacity and dropping currently at one foot every other day. The water supplied by the single groundwater well is inadequate to support the water demand of the community. This document addresses the current water supply emergency, the reliability of the existing emergency supply system, the projects and actions of the LDPCSD in support of securing additional water supply and extending our existing supply as long as possible. A summary is provided below with much more detail herein:
1. The Lake McClure water supply is dwindling quickly and if the drought conditions continue, we will not be able to pump lake water somewhere between the middle and end of March 2015.
2. We are planning for the immediate installation of three more groundwater wells and the potential for a permanent pump system in deeper water on Lake McClure. The District is applying for grants to pay for these critical projects to secure additional water supply.
3. The District has adopted mandatory water conservation measures requiring that all customers reduce their water usage by 30%, for all water used over 7 units (700 cubic feet) per month. The goal is to extend our water supply farther into the spring until the additional wells can be developed and placed in service.
2 BACKGROUND
The level of Lake McClure has always fluctuated widely based on weather, snowpack, MID water use and federal instream flow requirements that MID must meet in the river below the dam. The lowest lake level ever recorded was 588 feet above sea level, which occurred at the end of February 1991. Luckily the LDPCSD had constructed a cryptic floating pump system to continue pumping water to the plant below the 700 foot level. But at Barrett Cove the lake floor is at approximately 550 feet above sea level and we can only reasonably pump down to the 560 foot level. Just when we thought the community was going to run out of water, so much so that the District filed a lawsuit to stop MID from releasing water below the dam, along came the March Miracle in 1991 that began to fill the lake quickly and our water supply recovered for a bit. On many occasions since 1991 the use of the emergency float pumps have been necessary, and recently a new barge and pump was purchased for a more reliable system. But this water year is extremely bad. The lake elevation will fall to historically low levels by the 21st to 23rd of January, 2015; and the weather predictions are for continued and increasing drought conditions.
The District declared a Drought Emergency in February 2014, after the lake level had been below the pumps for over a year and the driest January (2014) on record had just passed. As the lake continued to drop drastically, by August 2014 the LDPCSD Board and management were discussing the possibility of mandatory water conservation measures. Feeling that the District needed to get its own system leaks under control and that the winter could bring good rains, the District chose to not adopt mandatory measures at that time. The previous manager left the District on October 3, 2014 and I joined the District as a contract manager on October 6, 2014.
Understanding the state water supply picture, operation of McClure, weather, drought funding and the District operations; I immediately began to work to find immediate water supply solutions and convince the LDPCSD Board to take a number of water supply related actions in November and December 2014 that have led us to where we are today. We hired a competent contractor to aggressively repair system leaks; which have for the most part been completed. The purpose of this discussion is to inform our community of the seriousness of the situation, to gain an understanding of the mandatory water conservation measures, and to discuss forward thinking solutions and actions.
3 WATER SUPPLY FACTS AND PROJECTIONS
• The total water consumption of our community is less than 500 acre feet annually, and the capacity of Lake McClure is 1 million acre feet.
• Lake McClure is currently filled to 69,000 acre feet, less than 7% of its capacity and the water surface elevation is currently dropping one foot every other day.
• The December rains did not fill the lake at all, and there is very little snowpack to fill the lake this spring. With the current weather patterns, it is predicted that we will no longer be able to pump water at the current location in Lake McClure after the end of March 2015; less than 90 days from now.
• The quality of the remaining water is unknown and can be easily contaminated by storm runoff. It is also unknown if we can actually pump water down to elevation 560 above sea level, as the lake has never been that low in history. • The Ranchito well has a safe yield of up to 50% of our winter water demand and approximately 15% of summer peak demand.
• Groundwater wells drilled in the region range from zero to over 300 gallons per minute, due to the fractured rock subsurface and variability of the geology in the area. The cost of a new well for a public agency like LDPCSD can be up to $500,000 if treatment is required for water hardness.
4 EMERGENCY WATER SUPPLY SYSTEM RELIABILITY
• The emergency pumping system consists of two 150 HP pumps mounted on a barge, 1200 feet of piping and electrical cable, a surge tank and one 150 HP booster pump on land This emergency pump system can cost up to $20,000 per month in electricity alone, and it takes the LDPCSD staff 20% of their available time to move and secure the barge weekly; taking them away from critical system maintenance and leak repairs. • As with any highly mechanical system, the emergency pump system is not 100% reliable for long term use and a pump failure could cause long term water outages due to the time required to repair or secure a new $40,000 pump. Currently, these pumps are running continuously in the summer, have tested poorly for their condition and the onshore booster pump has no backup.
• Overall, the emergency system functions well for short term periods in which the water level dips below 700 feet above sea level. The system is designed to function and the necessary pipe, electrical cable and fittings are in place to continue to follow the dropping water to the final elevation of 560 feet.
5 EMERGENCY WATER SUPPLY PROJECTS
The last thing a district manager wants to do is explain to customers that the system is out of water and we must either do without, or truck water into the water treatment plant at $20,000 per day. Some customers never like to hear that a public agency is spending millions of dollars “just in case” we might run out of water. But when you run out, those same customers and all others will ask “why didn’t you do something?” Immediately upon my arrival at the District in October 2014, I began to plan for projects to keep us in water no matter what. If the cost is too high or grants are not available, the customers can then make a decision, through the District Board, if they want to pay for the projects in advance of an outage. At this point we are moving as quickly as possible to secure the water supply without regard to whether grants are available, or not.
Within the past week, we have received two separate state grant commitments in the amounts of $200,000 and $60,000 to install a new groundwater well and to purchase the emergency pipe and electrical cable to follow the Lake McClure water to the bottom of the river. We are currently planning the following projects, which are all moving forward as quickly as the process and funding will allow:
5.1 THE INSTALLATION OF ADDITIONAL GROUNDWATER WELLS
We are preparing to drill from one to three wells with the goal of increasing our groundwater supply to approximately 300 to 500 gallons per minute or 1.3 to 2.2 acre feet of water per day. This amount of groundwater supply will meet between 70% and 100% of the peak summer water demand, without any water available from Lake McClure. All necessary wells are planned to be installed and operational by summer. The goal is to locate the wells in an area where their connection to our water treatment plant is possible, so the water can be treated consistently to state water quality standards. If the wells are located in an area remote from the water plant, treatment for iron and manganese removal will be required of us by the state. The total cost of the wells is estimated to range from $200,000 to $1.5 million. State grant commitments of $200,000 for the wells have been secured and we have submitted two other grant applications to state and federal agencies to fund the remainder.
5.2 THE INSTALLATION OF A DEEP WATER INTAKE (PUMP) SYSTEM ON LAKE MCCLURE
For over two decades, officials of the LDPCSD have been discussing the need to install pumps at Lake McClure in a location where the deepest water in the lake can be accessed with permanent pumps. The ideal location is near McClure Point, just east of New Exchequer dam. Pumps located in this area can reach down to an elevation of 440 feet above sea level, over 120 feet deeper than the emergency pumps in the current location. The MID management supports the construction of a deep water intake and has committed to financially support the project at some level.
The ideal time to construct the pump structure is now, when the lake level is at its lowest. The pumps must then be connected by approximately five miles of pipeline to the existing water supply pipeline on Ranchito at Merced Falls Rd. The project involves significant environmental review, complex engineering design and extensive permits from the Army Corps of Engineers, State Water Board and others to allow for construction. The total project cost is estimated at approximately $6 million and could take up to two years to complete.
6 OTHER LAKE DON PEDRO CSD ACTIONS
6.1 SYSTEM LEAK REPAIRS
In mid-October, we commissioned an effort to immediately address all water systems leaks with a goal of reducing system losses to less than 10%, in accordance with industry standards. The majority of leaks in the water system are now fixed as of this report; however more leaks seem to pop up daily and are occurring in the service lines which run from the water main to the meter box. Due to the nature of these line failures, replacement of the service lines is more cost efficient than their repair. Service line replacement takes our crew a full day to complete, and the crew can only be dedicated to this work a limited number of days per week. Contracted service line replacements can be more expensive than working with our crews, and the amount & cost of leakage in many cases does not warrant the added expense of contracted repairs. As of the end of December 2014, our system leaks are below 10%. 6.2 MANDATORY WATER CONSERVATION MEASURES
Effective December 3, 2014, the Board of Directors implemented mandatory water conservation measures, with a goal of reducing water consumption by 30%; for all water used over 7 units (700 cubic feet). Customers who use less than 7 units do not need to reduce consumption further; but most can if they try. The District website at www.ldpcsd.org contains extensive information regarding the measures and reference material to help customers reduce water use.
6.3 EMERGENCY SERVICES COORDINATION
The District is coordinating regularly with the state office of emergency services, and both Tuolumne and Mariposa County Departments of Emergency Services. The counties have been extremely helpful in coordinating emergency funding providers and facilitating communication with those agencies that can help us through this emergency.
6.4 OUTREACH MATERIALS
The District website at www.ldpcsd.org contains many tips and educational materials to help you reduce water consumption by 30%.
Source: Lake Don Pedro Community Services District
