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HomeMy WebLinkAbout; Lake Calavera Golf Course Water Supply; Lake Calavera Golf Course Water Supply; 1990-10-27LINDEN R. BURZELL CIVIL ENGINEER TELEPHONE P.O. BOX 369 (619)726-5856 VISTA. CALIFORNIA 92083 (619) 726-5362 (RES.) Report on the Water Supply for Lake Calavera Golf Course Carlsbad, California August 27, 1990 by LINDEN R. BURZELL Civil Engineer 1002 BONNIE BRAE PL, VISTA, CALIFORIA 92084 LINDEN R BURZELL CIVIL ENGINEER TELEPHONE P.O. BOX 369 (619) 726-5856 VISTA. CALIFORNIA 92083 (619) 726-5362 (RES.) Report on the Water Supply for Lake Calavera Golf Course Carlsbad, California August 27, 1990 Summary The City of Carlsbad owns approximately 220 acres including Lake Calavera and surrounding property which is being considered for a municipal golf course. There is considerable community interest in the project and the expectation is that the golf course can be constructed in the near future. The water supply for the golf course is of concern to elected officials and planners who acknowledge forecasts of future shortage of imported water. This study describes alternate water supplies which may be developed during the life of the golf course which would reduce the demand for water from the potable imported water supply provided by the San Diego County Water Authority. These alternate water source include shallow wells in the vicinity of the project which would produce water from 50 to 200 foot depths in the underlying alluvium formation, deep wells of 1,000 to 1,500 feet or.more which penetrate the rock which underlies the shallow alluvium and reclaimed water from the nearby sewage treatment plants. The study indicates that the Lake Calavera Golf Course is likely to have one or more of these alternate water sources available within three to five years and that within five to ten years reclaimed water will be available. For this reason the Lake Calavera Golf Course should be provided initially with, dual water systems so that the alternate water supplies can be kept separate from the potable water supplies as they become available. If the golf course is constructed within two or three years, the likelihood is that imported water will be used exclusively during the startup period. The report concludes that at least two shallow test holes and two deep hard rock test holes be drilled to provide additional information on the quantity and quality of the available water in the underlying formation. 1002 BONNIE BRAE PL., VISTA, CALIFORIA 92084 Geology The Lake Calavera Golf Course site is underlain with a Cretaceous-age granitic batholith or bedrock. Calavera volcanic rock is present in the form of an intrusive slug exposed in the rock quarry just south of the Golf Course site. The surface of the site is mostly Tertiary-age Santiago Formation sedimentary silty sands to clayey silts with lenses of claystone and siltstone. The surface material in the drainage areas is typically alluvium and slopewash materials or stream terrace deposits made up of silty sands and clayey sands. The potential for shallow water wells (50 to 200 feet) is in the loose alluvium, stream terrace deposits and the weathered portions of the Santiago Formation and the contact zones between different formations. The potential for deep wells (depth to 1500 feet or more) is the fractured zones of the granite batholith and also for water which may have accumulated in the contact zones between the different geologic formations. Shallow groundwater was encountered in on site excavations in the northeastern portion of the site and near the Lake. The general geology and subsurface geological conditions are described in detail on pages 4 through 7 of the Southern California Soil & Testing, Inc. Report of Geotechnical Investigation Calavera Lake Golf Course dated October 4, 1989. Existing Nearby Local Wells ^ depths to 200 feet The San Diego office of the Unites States Geological Survey was contacted for well records. Very little factual information was available in the vicinity of Lake Calavera. Most of the wells which we have general knowledge of were drilled prior to the time that well drillers were required to obtain drilling permits and to file the resulting well logs. Early studies include Water-Supply Paper 446, a United State Geological Survey study by Ellis and Lee, which provides the best history of local wells (Ref. pages 169-174). , Water-Supply Paper 446 describes many low capacity domestic wells in the coastal area between Oceanside and Del Mar. None of these wells produced more than 50 gallons per minute. Nearly all of these wells were dug wells rather than drilled and cased gravel packed wells. Long time Carlsbad resident Allen 0. Kelly was contacted on July 11, 1990. Mr. Kelly did not know of any wells drilled above Lake Calavera and was of the opinion that the surface water above the Lake was greater now than in the past probably due to return water from irrigation of landscaping and street drainage. Mr. Kelly's recollection of the well located just south of the Lake was that the production was relatively modest, perhaps 50 gpm and that there was concern that the production was coming in part from the Lake rather than from the aquifers underlying the Lake. -2- Regarding wells in the Aqua Hedionda basin southwest of Lake Calavera, Mr. Kelly's recollections are that the wells in this area were as deep as 80 feet before reaching bedrock and that the capacities were in the range of 100-150 gpm, very spotty and susceptible to droughts. Mr. Kelly acknowledged that current flows in the Aqua Hedionda basin seemed to be greater now than it was historically due to the return flows from irrigation. Mr. Kelly indicated that he agreed that it may be possible to develop significant quantities of water from shallow wells. Deep Hard Rock Wells The possibility of locating water of acceptable quality in fractured sections of deep hard rock formations has improved substantially in recent years. Drilling equipment and techniques have improved and costs are in line with results. The difficulty is in locating fractures which are extensive and interconnected sufficiently to permit significant quantities of water to be extracted over time without depletion. Drilling techniques today usually involve air hammer down hole drills with foam additives to expel cuttings as opposed to the older method of roller rock bit rotary drilling methods with mud circulation to remove cuttings. Several successful deep hard rock wells have been drilled in northern San Diego county in recent years in Oceanside, San Marcos and the Pauma Valley. Typically, the better wells are 250-600 gpm. Water quality varies from location to location averaging about 600 ppm of total dissolved solids with a high of 900. The best wells were drilled to at least 1000 feet and in at least two locations to over 1200 feet. For every successful well there are perhaps 5 to 10 + poor wells drilled where either the production in non existent or very low. In some cases the dissolved minerals are too high, hence the well has marginal value. Even a 10 or 15 gpm well could be considered a successful well for a single family private home or isolated ranch. Lake Calavera Golf Course needs larger capacity wells in the range of 100 to 250 gpm to justify the capital cost and the maintenance and operations expense. i There are private enterprise firms who drill water wells at their risk. The business principal is that they will drill wells and if successful the client will buy the water for a predetermined price less the cost of power to pump the water. For example, it may be feasible for a private firm to drill deep wells for the City of Carlsbad if the City will agree to pay say 90* of the cost of purchasing water from the San Diego County Water Authority less power costs. There is attached in the Appendix, Item 1 a letter dated July 20, 1990, from a qualified water development firm SRT/Resources Development, Inc., which indicates an interest in finding water for the Lake Calavera Golf Course. -3- The water quality of water produced from deep wells cannot be predicted in advance. If deep wells are drilled on the Lake Calavera property at elevation 350 and the well is 1000 feet in depth, the bottom of the well will be 650 below sea level. This situation requires locating fractured rock formations where the pool of water in storage is at a higher elevation than sea level, otherwise, the water produced from the well will gradually increase in salinity due to sea water intrusion. Lake Calavera _^ Storage and Runoff During the course of this study, this consultant met with the lead consultant, Don Collett & Associates, and other members of the design team on a regular basis. It became apparent that esthetics and environmental concerns precluded the use of the Lake for irrigation storage. The preliminary design called for a lake level of about 208 feet. The spillway is about 216 feet. If the Lake is operated at about 208 feet elevation, surface runoff will be released gradually downstream to maintain the uniform lake level. The contributory drainage area above La Casa del Zorro is approximately 2500 acres. The annual surface runoff has not been determined in recent years, however, is probably in the range of 100 to 300 acre feet annually. Nearly 100% of this inflow occurs from Nov 1 to May 1 each winter. In order to make use of this surface runoff, it would be necessary to impound water in the winter months to nearly spillway level and then gradually draw the level down throughout the summer months; this variable water depth of 15 to 20 feet or so would not be aesthetically acceptable. The best way to make use of the available local water appears to be to develop the groundwater. This consultant presumes that the City of Carlsbad will continue to regulate the outlet works of Lake Calavera to maintain a predetermined lake level of about 208 feet. In very dry years some makeup water may be required from the secondary water system in order to maintain this level. It is not considered feasible to store surface runoff for irrigation with the incumbent seasonal cycling of the elevation of the water surface. Dam safety, reservoir operation and flood control are beyond the scope of this report. ; Reclaimed Water The City of Carlsbad has undertaken reclaimed water use studies which will lead to projects which will distribute reclaimed water throughout the City. The Luke-Dudek study on this subject is expected to be implemented in the near future. This study calls for construction of reclaimed water distribution facilities throughout the City in Phases I through V. The target areas for use of reclaimed water include agriculture, parks, schools, landscaped areas, residential areas, commercial areas, industrial areas, freeways and golf courses. -4- The Lake Calavera area falls in the Phase III time period to receive reclaimed water. It may be possible to construct a portion of the Phase III reclaimed water distribution system as part of the Lake Calavera Golf Course. This possibility is discussed later in this report under Optional Water Supply Plans 2 and 3. Reclaimed water is somewhat higher in dissolved mineral content than that of the potable water supply provided by the Carlsbad Municipal Water District. It is anticipated that over time the City of Carlsbad can anticipate that the total dissolved solids concentration of the reclaimed water delivered within the City will be in the 800 ppm range which will be acceptable for all irrigation uses on the golf course and landscaping. Water Requirements ^_ Quantity The Lake Calavera Golf Course irrigation system is being designed by Gordon's Irrigation Consulting of Laguna Hills, California. Mr. Gordon's preliminary plan calls for maximum irrigation flows of 1,958 gpm over an 8 hour irrigation period with a possible error of plus or minus 5%. Accordingly, the maximum rate of flow from storage for design should be 1,958 x 1.05 or 2,056 gpm. The total daily requirement is forecast to be .827 MG. The inflow to storage will come from reclaimed water, groundwater and makeup water from the potable water system. This flow can be provided off peak or uniformly over a 24 hour period using a 1 MG tank for regulation. The average inflow will be about 574 gpm. If the inflow is delivered over a 12 hour period the inflow would be 1,148 gpm. It is recommended that the pipelines serving the golf course be sized to provide the rates of flow described above. Water Requirements ^ Quality The mineral quality or total dissolved solids concentration of the water available for golf course irrigation is one of the controlling factors on the quality of grass. Greenskeepers prefer low mineral content water because It is easier to grow good grasses. With the increased use of reclaimed water and the' accompanying higher mineral content, greenskeepers and golf course architects have discovered ways to continue to grow good grass by using new strains of salt tolerant grasses and by designing improved drainage features into the greens and tees. In order to prepare Lake Calavera golf course for reclaimed water the greens and tees should be provided with high quality PGA type soil mixtures. Well drained soils and use of selected grasses will permit use of reclaimed water and moderately high salinity groundwaters to be used throughout the irrigated area. -5- The water supply for irrigation to Lake Calavera golf course should be within the following ranges of total dissolved solids concentrations: Imported Water: - 500 - 600 ppm Reclaimed Water: - 800 - 900 ppm Groundwater: - 600 - 1.000 ppm Water Cost The water to be delivered to Lake Calavera golf course will be provided by the Carlsbad Municipal Water District system. The water rate is set by the District and the City of Carlsbad by Resolution. These rates are modified froa time to time based on the cost of water received from the San Diego County Water Authority and the cost of distribution and reclamation. In August, 1990, the Carlsbad Municipal Water District was paying $277.00 per acre foot for imported treated water received from the San Diego County Water Authority. The City of Carlsbad bills its users at the rate of $439.96 per acre foot ($1.01/100 cubic feet) for water. The estimated initial annual cost for irrigation water for the Lake Calavera golf course is $186,543. This is based on the current water rate and the forecast by Gordon's Consulting that the golf course will require about 424 acre feet per year. When reclaimed water becomes available, the annual cost for irrigation water would drop to about $152,500 if the current rate for reclaimed water is maintained and all irrigation water is reclaimed. Water cost to the City can be reduced if exploration of groundwater produces significant quantities of water of suitable quality. -6- Conclusions 1. Greens will require special design consideration in order to thrive with a blend of secondary water for irrigation. 2. Fairways and landscaping can tolerate a secondary water supply based on reclaimed water, water from shallow wells or water from deep rock formations provided TDS does not exceed 1,000 ppm. 3. Air gap separation will be required between the potable water supply and the secondary water sources, the potable source must discharge to atmosphere into a storage tank, surface pond or Lake Calavera. 4. A secondary water system should be provided. It should include off site and onsite facilities, storage, transmission mains, distribution mains, and pumps to pressurize the secondary water system to the hydraulic grade necessary to irrigate the golf course and landscaping. 5. The off site portion of the secondary water system for the golf course should be planned in accordance with the reclaimed water distribution master plans as described in Phase III of the Luke Dudek report. 6. The investigation of shallow groundwater resources justifies drilling at least 2 and perhaps as many as 5 test holes in the shallow alluvium. The first 2 test holes should be drilled on site. 7. The investigation of deep groundwater in the underlying hard rock formation justifies at least 2 onsite test holes each of which should be drilled to depths of 1000 to 1500 feet. 8. The potable water source of water for the golf course project is the existing 21" Carlsbad Municipal Water District pipeline which was built by the San Diego County Water Authority in 1979 as part of the Trl Agencies pipeline. This pipeline lies south of the golf course . property approximately 600 feet and runs roughly parallel to the southerly boundary. 9. If reclaimed water and groundwater are made available, the long term cost of water for the golf course will be significantly less than the cost of using potable water. 10. The forecast of success in developing significant quantities of groundwater is that one useful well will result from each five to ten test holes drilled and tested. -7- Three Optional Water Supply Plans Plan 1. Potable water for domestic purposes and a secondary supply from onslte shallow and deep wells and reclaimed water in the future. System requirements: (1) 4 test holes - completed wells based on evaluation of test hole results. (2) Provide dual water systems, one system for potable water and a separate system for secondary water. a. Potable offsite, 12" pipeline from CMWD, 21" Tri Agencies pipeline to site. b. 1 MG Tank on site for secondary water at elev. 350. Tank will provide for well water, future storage for reclaimed water and delivery point for make up water from potable system with air gap separation. A booster pump will be required for the golf course irrigation hydraulic grade which may be as much as 500 feet. Plan 2. Potable water for domestic purposes and a secondary supply from both onsite and offsite shallow and deep wells and reclaimed water when it is available to Tank C. System requirements: (1) 4 test holes - completed wells based on evaluation of test hole results. Sites may be onsite or offsite. (2) Provide dual water systems, one system for potable water and a separate system for secondary water. ; a. Potable offsite, 10" pipeline from CMWD, 21" Tri Agencies pipeline to site. b. Use existing offsite 1 MG Tank C elev. 392 feet converted to secondary storage, feed tank from 14" Line C with air gap separation construct ultimate reclaimed water pipeline for Phase III from Tank C to golf course about 3,900 feet. -8- Plan 3. Potable water for domestic purposes and a secondary supply from both onsite and offslte shallow and deep wells and reclaimed water when it is available to Tank C. System requirements: (1) Test holes and wells same as scheme 2. (2) Provide dual water systems same as scheme 2. a. Potable offsite 10" pipeline from CMWD as in scheme 2. b. Use existing offsite 1 MG Tank C elev. 392 feet converted to secondary storage together with Pipeline C from El Camino Real to Tank. Feed Tank C from 21" CMWD pipeline with air gap separation and construct ultimate reclaimed water pipeline for Phase III from Tank C to golf course. Plan 3 opens up many additional opportunities for shallow wells along the route of the pipeline as well as onsite. Plan 3 assumes that CMWD will be able to transfer the pipeline and Tank C to the reclaimed water system without much cost. -9- PRELIMINARY COST ESTIMATES FOR DUAL WATER SOURCES 1. Shallow test holes (2) 2. Completed wells (2) 3. Deep test holes (2) 4. Completed wells (2) 5. Offslte potable water main and connection 6. Dual water systems onslte 7. 1 MG Tank onslte 8. Convert Tank C to secondary water storage and 3900 feet of 12" pipeline 9. Convert Tank C and Pipeline C to secondary water and provide make-up water to Tank C from the Tri Agency Pipeline PLAN 1 60,000 80,000 140.000 100,000 35,000 by others 350,000 PLAN 2 60,000 80,000 140,000 100,000 30,000 by others 0 PLAN 3 60,000 80,000 140,000 100,000 30,000 by others 0 160,000 Total $ 765.000 0 = = = E±r== = = = 570,000 230,000 640,000 -10- MAPS 1. Plan 1 2. Plan 2 3. Plan 3 -11- PLAN No. 1 IMG TANK for Secondary Water TEST HOLES 12" POTABLE WATER PIPELINE SCHEMATIC POTABLE HATER PIPELINE SCHEMATIC SECONDARY WATER PIPELINE minim PLAN No. 2 TEST HOLES ' ^ 12" SECONDARY WATER PIPELINE JJ1C*2» 10" POTABLE WATER PIPELINE ' HIIIIIIII SQ1Q1ATIC POTABLE WftTER PIPELINE ^^^^ EaiH-lATIC EEXBNmRY WATER PIPELINE •—••••• EXISTING TANK C • . OONVERTED TO SECONDARY HATER STORAGE PLAN No. 3 TEST HOLES 12" and EXIST. 14" PIPELINE CONVERTED TO SECONDARY WTER . 10" POTABLE WATER PIPELINE SCHEMATIC POTABLE HATER PIPELINE SCHEMATIC SECONDARY HATER PIPELINE " !.'••' EXISTING TANK C CONVERTED TO'SECONDARY HATER STORAGE Illlllllll Recommendations 1. That a commitment be made to provide and use reclaimed water when reclaimed water becomes available. 2. That an Investigation be made of both shallow and deep groundwater with the goal being to find a significant quantity of water suitable for irrigation. At least two test holes should be drilled and as many as five test holes appear to be justified. 3. That the golf course irrigation system be constructed initially to provide for storage and distribution of secondary water including both reclaimed water and groundwater separated by air gap facilities from the potable water system. 4. That the best plan to serve Lake Calavera golf course is Plan No. 3. 5. That the City of Carlsbad consider the private enterprise approach for developing groundwater as proposed by firms such as SRT/Resources Development, Inc. (See Appendix). 6. Groundwater produced by local wells should be utilized if its dissolved mineral concentration does not exceed 1,000 ppm or it can be blended with other water to meet that criteria. 7. A general mineral laboratory test be performed on the water produced by each test hole before undertaking completion of the test hole into a producing well. -15- W APPENDIX 1. Letter to Linden R. Burzell from SRT/Resources Development, Inc.,regarding wells dated July 20. 1990. 2. Memorandum dated July 13, 1990, re Interview with Allen 0. Kelly -16- SI/RESOURCES DEVELOPMENT, INC. July 20, 1990 Linden Burzell Post Office Box 369 Vista, California 92083 Dear Lin: Thank you for the opportunity to work with you on the proposed Carlsbad golf course. The project appears to be interesting and challenging. SRT Resources Development's primary concept is to find water on behalf of beneficial users and to be compensated for our risk, exploration and drilling expense by some means directly tied to water production. In this concept we have assumed an able and willing beneficial user who can utilize the water in a timely manner. In our discussions on the Carlsbad golf course project it appears the actual use for any water we may find may be an extended period, up to a few years after we have completed our task. This would create a problem for us due to the fact that we would have capital invested with no short-term method of realizing a return on our capital. In view of the above, I suggest a situation where upon successful completion of a well we are compensated for our direct cost and a "standby" fee paid at a fixed amount until the well is put into production. After production begins the standby fee would stop and we would receive a royalty per acre foot to enable us to ,be compensated for our exploration expense and risk exposure. Once again, we look forward to working with you and welcome your suggestions concerning a compenstion package which will be fair to both Carlsbad and SRT Resources Development. Yours tr: Ron Fergus General Manager ""2170 El Camino Real, Suite 211 (619) 757-2750 WDceanside, CA 92054 FAX (619) 721-3141 — July 13, 1990 *•> Interview with Allen Q.. Kellv by telephone July llr 1990 (438-0668) regarding— water from shallow wells ** Mr. Allen Kelly is currently recovering from a heart attack. Mr. Kelly «• and I discussed local groundwater conditions in the Calaveras Lake area and the Aqua Hedionda drainages with me at some length. Mr. Kelly is a longtime m Carlsbad resident and pioneer in local water supply, also a landowner in the Aqua Hedionda drainage area. ^ Allen feels that the springs and surface drainage upstream from Calavera Lake are flowing more now due to seepage from irrigation of landscaping plus * street drainage. He did not recall any good wells in this area. He did not -^ know of the Alvarado Well, if one exists as suggested by Mr. Burton of SDG&E. *"• Allen seemed to recall a test hole drilled by the City of Carlsbad at the — suggestion of a City Councilman some time ago. The well was located 50 feet from the south side of the Lake. The flow was relatively modest (50 gpm or «•> so) and what they were pumping could have been circulation from the Lake. ** .«, Allen's recollections of the Aqua Hedionda basin north of and parallel to ^ El Camino Real was that some wells were as deep as 80 feet before hitting ** bedrock. Capacities were better (perhaps in the 100-150 gpm range) spotty and «* susceptible to drought. Allen agrees that the current surface flow indicates that perhaps significant quantities of water could be developed. He feels •" that the present surface flow is higher than it was historically due to return — flows from irrigation. Allen believes that the golf course in this area is operating a well currently. The basin may be deepest near the Rusty Grove property. -,- SELECTED REFERENCES 1. Southern California Soil and Testing, Inc. - Report of Geotechnical Investigation, Calaveras Lake Golf Course, October 4. 1989. 2. United States Geological Survey, Water Resources Investigations, Report 85-4032, Evaluation of the Mission, Santee, and Tijuana Hydrologic Subareas for reclaimed water use by J. A. Izbicki. 3. United States Geological Survey, Geology and Groundwaters of the Western Part of San Diego County, California, Water Supply Paper 446 by Ellis and Lee