Dennis Jackson - Hydrologist 2096 Redwood Drive Santa Cruz, CA (831)

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1 February 11, 2011 Dennis Jackson - Hydrologist 2096 Redwood Drive Santa Cruz, CA (831) dennisjack01@att.net Tom Lippe 329 Bryant Street, Suite 3D San Francisco, CA Re: Additional Information on Mitigated Negative Declaration for Dunphy P ECPA Dear Mr. Lippe: You have asked me to comment on the potential impacts of the proposed Dunphy Vineyard conversion from oak woodland and grassland to vineyard. A Mitigated Negative Declaration (MND) was prepared, dated September 11, After several cycles of review a revised IS/MND was prepared, dated February 14, 2010 (probably 2011). In this letter, I present new information regarding Dry Creek. The new information includes three additional Department of Fish and Game (DFG) reports concerning Dry Creek. These reports are: June 13, 1977, Stream Survey of Dry Creek from Highway 29 to the headwaters by Alan Baracco. July 21, 1981, Steelhead trout rescue report by John Ellison Fish Population Survey, Dry Creek, Napa County, by John Emig. I also present the findings of a Stream Depletion study prepared for the State Water Resources Control Board Division of Water Rights. June 1977 Fish and Game Report The three DFG reports referenced above are attached to this report. The June 1977 report covered approximately 12.2 miles between Highway 29 and the headwaters of Dry Creek. The field work was done on June 13 and June 14, The report contains two pages of text and three map pages. The survey was done in the second year of the drought. The June 1977 Stream Survey describes the flow in Dry Creek as follows: Flow: The creek has continuous flow in approximately 3 miles of the mid-section, between unnamed tributaries N-4 and S-5. The stream was dry from Highway 29 to approximately 2.5 miles upstream and from the headwaters downstream to approximately 1 mile downstream, with the exception of a pool below tributary N-1. All other areas of the stream had intermittent flow. Flows were measured at two locations: 0.12 cfs at Station 1 and 0.14 cfs at Station 2 (see sketch map). Figure 1, below, shows page 1 of the June 1977 DFG sketch map. The sketch map was created by tracing the USGS 7.5-minute topographic maps for Dry Creek. The June 1977 DFG sketch map shows the location of the pool (Pool 1) they observed downstream of tributary N-1. Figure 2 was created by overlaying the 1977 sketch map on a USGS 7.5-minute map and marking the location EXHIBIT 1

2 Dunphy Vineyard February 11, 2011 Page 2 of 31 Figure 1. The sketch map from the June 1977 DFG survey of Dry Creek was created by tracing the USGS 7.5-minute topographic maps that cover Dry Creek. A total of three sketch map sheets were required to cover the area of the survey. Page 1 of the sketch map covers the area from Highway 29 to upstream of the Dunphy property.

3 Dunphy Vineyard February 11, 2011 Page 3 of 31 Figure 2. The location of the pool observed in June 1977 was determined by overlaying the 1977 sketch map on the 7.5-minute topographic map. The June 1977 pool location is about 4,200 feet downstream of the Dunphy property. The 1977 pool is close to the pools where steelhead trout were observed in the summer of 2000 (star on map). Mile distances are from Highway 29, the start of the 1977 survey.

4 Dunphy Vineyard February 11, 2011 Page 4 of 31 of the June 1977 pool and the location of isolated pools where juvenile steelhead trout were observed in the summer of 2000, along with the location of the Dunphy property. The location of the pool observed in June 1977 was estimated to be approximately 1,200 feet downstream of tributary N-1, just downstream of a summer crossing. The location of the pool observed in June 1977 is approximately 550 feet upstream of the isolated pools where steelhead trout were observed in the summer of The Dunphy property is about 4,200 feet upstream of the location of the pool that was observed in June The 1976 and 1977 water-years were a severe drought in California. The 1976 water-year rainfall was inches and the 1977 water-year rainfall was inches, at the Napa State Hospital. The mean rainfall at the Napa State Hospital from 1918 through 2010 (93 years) was inches. The 1976 water- was the fifth driest year and the 1977 water-year was the second driest year for the year period. Since 1977 was the second year of a severe drought, the presence of the June 1977 pool indicates that it is likely that a pool(s) can persist through the dry season of most years in this general vicinity. The summer 2000 observation of juvenile steelhead trout approximately 550 feet downstream of the June 1977 pool indicates that juvenile steelhead can be expected to use the pools in the vicinity through the dry season. The June 1977 Stream Survey was a broad-brush assessment of 12.2 miles of Dry Creek based on a two day field trip. Steelhead trout were observed but their density was only estimated (5 fish per 100 feet of creek) in the 6 mile reach between tributary S-1 and tributary N-7 (tributary S-1 is about 1,900 feet upstream of the Dunphy property). Steelhead trout may have been present in other portions of Dry Creek but their density was either not estimated or reported. Juvenile steelhead trout are wary and their presence may be missed while walking a creek. DFG typically uses electro-fishing equipment to do quantitative assessments of juvenile steelhead trout which was not done during the June 1977 survey. Therefore, it is possible that juvenile steelhead trout were present in the pool observed downstream of tributary N-1 during June 1977 even though their presence was not specifically recorded in the June 1977 report. The June 1977 establishes the presence of a pool during a significant drought, approximately 4,200 feet downstream of the Dunphy property. July 1981 Fish and Game Report The July 21, 1981 report by John Ellison, DFG, describes a juvenile steelhead trout rescue operation that took place on June 17, Juvenile steelhead trout were captured between Dry Creek Road and Highway 29. A total of 1,182 juvenile steelhead trout were captured but 212 of them died. The remaining 970 juvenile steelhead trout were taken to DFG s Silverado Base facility. The 212 dead steelhead trout were weighed and their fork-length was measured. There is also a hand-written report of a reconnaissance walk on June 15, 1981 along 5.5 miles of Dry Creek to locate stranded juvenile steelhead trout. The hand-written report included a copy of a USGS 7.5- minute topographic map showing that the reconnaissance walk covered the area from the mouth of Dry Creek to a point past the USGS Dry Creek near Napa stream gauge, roughly 1.3 miles upstream of the Dunphy property. There are several illegible notes on the map along with some X s. At least one of the notes appears to be a temperature. Figure 3 shows the map from the June 15, 1981 reconnaissance walk. The 1981 water-year rainfall total was inches at the Napa State Hospital. The 1981 water-year was the 18 th driest year during the 93 year period from 1918 through 2010.

5 Dunphy Vineyard February 11, 2011 Page 5 of 31 Figure 3. The map from the June 15, 1981 reconnaissance walk to locate stranded fish has illegible notes, X s and what appears to be water temperatures.

6 Dunphy Vineyard February 11, 2011 Page 6 of Fish and Game Population Survey John Emig assessed the fish populations of Dry Creek by electro-fishing five 30-meter sections in September and October of The 1983 water-year was the wettest year during the 1918 through 2010 period with a total of inches of rain at the Napa State Hospital. Figure 4 shows the location map for the September-October 1983 fish population study (Emig s Figure 1). Figure 5 shows the locations of Emig s Stations 1 and 2 overlain on Figure 2. The downstream end of the 1983 fish population study was at Tributary N-1 from Figures 1 and 2. Emig s Station-1 was located approximately 1,300 feet downstream of the Dunphy property and Station-2 was located about 4,150 feet upstream of the Dunphy property. Table 1 and Table 4 are from Emig s 1983 Fish Population Study of Dry Creek. Table 1 gives the number of each fish species captured at each station. Stations 1 and 2 had the lowest number of steelhead trout of the five Dry Creek stations. Table 4 shows the mean fork-length of the steelhead trout captured at each station along with the number of fish and the standard deviation (S.D.). Stations 1 and 2 had the largest mean fork-length of the five stations. So, Stations 1 and 2 had fewer steelhead trout but they were larger than the steelhead captured at the other stations. These observations are based on Emig s discussion of steelhead trout quoted below. The mean FL (fork-length) of steelhead in Dry Creek was calculated at 90.4 rnm (Table 3). This is higher than the 60 mm mean FL found by Anderson (1969). A histogram of the steelhead fork length in Dry Creek (Figure 2) indicates a bimodal distribution. One group is from 50 mm FL to about 110 mm FL, another from 110 mm FL to about 170 mm FL. Larger fish were found in the lower section of the stream (Table 4). Dry Creek steelhead were more abundant in the upper area (Stations 4 and 5), but larger fish and the greatest biomass were found in the lower area (Stations 1 and 2). In other California streams, trout have been reported to be most abundant and of larger size when in association with other species (Moyle et al 1982). Although fewest Dry Creek steelhead were found in association with large numbers of other species, they were of greater and attained a high biomass. As noted by Moyle, et al (1982), The larger of the steelhead in the lower area probably due to the presence of deep pools providing more diverse habitat, warmer water, and higher productivity. Emig notes that Stations 1 and 2 had the larger fish and greater biomass than the upper stations. Emig that steelhead in the lower area (Stations 1 and 2) were able to grow large because of the presence of deep pools with diverse habitat.

7 Dunphy Vineyard February 11, 2011 Page 7 of 31 Figure 4. The September-October 1983 Fish Population study of Dry Creek was done between Montgomery Creek, in the headwaters, and a point upstream of Highway 29.

8 Dunphy Vineyard February 11, 2011 Page 8 of 31 Figure 5. The location map from Emig s 1983 fish population study was overlain on Figure 2. The locations of Emig s Station 1 and 2 were then transposed to Figure 2. The downstream end of Emig s 1983 fish population study was at Tributary N-1 on from Figure 2.

9 Dunphy Vineyard February 11, 2011 Page 9 of 31 It is known that larger size decreases steelhead trout mortality during downstream migration. Larger juvenile steelhead trout are more likely to return to spawn than smaller fish. The juvenile steelhead trout from Stations 1 and 2 are more likely to return to spawn than the fish captured at the other stations. The steelhead trout and their habitat in the vicinity of Station 1 are more likely to experience adverse impacts from the Dunphy project than the other stations sampled by Emig in Figure 5 shows that juvenile steelhead trout have been observed in the vicinity of the Dunphy project during the dry season. The observation of the pool downstream of tributary N-1 in June 1977 demonstrates that pools can exist on Dry Creek in very dry years. A Brief Discussion of Groundwater The following definitions are from Bates and Jackson, 1984, Dictionary of Geological Terms, American Geological Institute: Groundwater (Ground Water); (1) That part of subsurface water that is in the zone of saturation, including underground streams. (2) Loosely, all subsurface water as distinct from surface water. Aquifer; A body of rock that is sufficiently permeable to conduct groundwater and to yield economically significant quantities of water to wells or springs. Aquiclude; A body of rock that will absorb water slowly but will not transmit if fast enough to supply a well or spring. Aquifuge; A rock which contains no interconnected openings or interstices and therefore neither absorbs nor transmits water. Aquitard; A confining bed that retards but does not prevent the flow of water to or from and adjacent aquifer; a leaky confining bed. It does not readily yield water to wells or springs, but may serve as a storage unit for groundwater.

10 Dunphy Vineyard February 11, 2011 Page 10 of 31 Confining Bed; A body of impermeable or distinctly less permeable material stratigraphically adjacent to one or more aquifers. (Stratified: Formed, arranged or laid down in layers or strata; especially said of any layered sedimentary rock or deposit). Confined Aquifer; An aquifer bound above and below by impermeable beds, or any beds of distinctly lower permeability than the aquifer itself; an aquifer containing confined groundwater. Unconfined Aquifer; Groundwater that has a free water table, i.e. is not confined under pressure beneath relatively impermeable rocks. Joint; A surface of fracture or parting in a rock, without displacement; the surface is often plan and may occur with parallel joints to form a joint set. Fault; A fracture or fracture zone along which there has been displacement of the sides relative to one another parallel to the fracture. Shear; A deformation resulting from stresses that cause contiguous parts of a body to slide relative to each other in a direction parallel to their plane of contact. It is the mode of failure in which a portion of a mass on one side of a plane or surface slides past the portion on the opposite side. It is also used to refer to surfaces and zones of failure by shear, and to surfaces along which differential movement has taken place. Shear Zone; A tabular zone of rock that has been crushed and brecciated by many parallel fractures due to shear strain. Shear Stain; A measure of the amount by which parallel lines have been sheared past one another by deformation. Breccia; A coarse-grained clastic rock, composed of angular broken rock fragments held together by a mineral cement or fine-grained matrix. Clastic; Pertaining to a rock or sediment composed principally of fragments derived from pre-existing rocks or minerals and transported some distance from their place of origin; also said of the texture of such a rock. Clast; An individual constituent, grain, or fragment of a detrital sediment or sedimentary rock, produced by the physical disintegration of a larger rock mass.. The definition of an aquifer is based on its function. Driscoll (1986) discusses the function of aquifers. A portion of his discussion follows. Aquifer Functions An aquifer performs two important functions a storage function and a conduit function. The interstices of a water-bearing formation act as storage sites and are part of a network of conduits.

11 Dunphy Vineyard February 11, 2011 Page 11 of 31 Groundwater is constantly moving through these conduits under the local hydraulic gradient. Rates of movement vary from a feet per year to feet per day. Thus, water contained in any aquifer is in temporary storage, and if not used, will be discharged to springs, lakes, streams or oceans. Our previous examination of groundwater environments indicates that openings in aquifers comprise three general classes. 1. Openings between individual particles in sandstone and sand and gravel formations. 2. Crevices, joints, faults, and gas holes in igneous and metamorphic rocks. 3. Solution channels, caverns, and vugs (openings) in limestone and dolomite. The shape of the openings in the rocks or sediment, their size, volume, and interconnection all play a vital part in the hydraulic characteristics of an aquifer. In an unconfined aquifer the hydraulic gradient between two points separated by some distance is the result of the difference in elevation between the two points. In an unconfined aquifer, water flows downhill. In a confined aquifer the hydraulic gradient is the result of a difference in pressure between the two points of interest. In an unconfined aquifer, Driscoll (1986) says: When a pump is turned on in a well, a significant elevational difference is created between the water surface in the well and the surrounding aquifer. This difference in elevational head forces the water in the aquifer to flow towards the well. In a confined aquifer, Driscoll (1986) says: When a well is drilled through an overlying impervious layer into a confined aquifer, water rises in the well to some level above the top of the aquifer. The water level in the well represents the confining pressure at the top of the aquifer. Confined pressure is defined as the vertical distance between the water level in the well and the top of the aquifer. This is equivalent to the hydrostatic head, expressed in feet (meters) of water. When a well penetrating a confine aquifer is pumped, internal aquifer pressure is reduced and the overlying sediments compact the aquifer. But the pores in the rock remain saturated as long as the pumping water level remains above the aquifer. Should the potentiometric surface of a confined aquifer fall below the top of the aquifer itself during pumping, it then becomes a partially confined aquifer. Stream Depletion Study In May 2010 the State Water Resources Control Board (SWRCB) adopted the Policy for Maintaining Instream Flows in Northern California Coastal Streams (the Policy). The provisions of the Policy became effective on September 28, The first four paragraphs of the Policy are quoted below to set the context for the discussion of Stream Depletion Areas. POLICY FOR MAINTAINING INSTREAM FLOWS IN NORTHERN CALIFORNIA COASTAL STREAMS 1.0 INTRODUCTION The State Water Resources Control Board (State Water Board or Board) adopted this state policy for water quality control on May 4, This policy is also known as the North Coast Instream Flow Policy. It applies to applications to appropriate water, small domestic use and livestock stockpond registrations, and water right petitions. Water Code section , which was added by Assembly Bill 2121 (Stats. 2004, ch. 943, 3), requires the State Water Board to adopt principles and

12 Dunphy Vineyard February 11, 2011 Page 12 of 31 guidelines for maintaining instream flows in northern California coastal streams as part of state policy for water quality control, for the purposes of water right administration. This policy implements Water Code section The geographic scope of this policy, referred to as the policy area, extends to five counties Marin, Sonoma, and portions of Napa, Mendocino, and Humboldt counties and encompasses (1) coastal streams from the Mattole River (originating in Humboldt County) to San Francisco, and (2) coastal streams entering northern San Pablo Bay. This policy focuses on measures that protect native fish populations, with a particular focus on anadromous salmonids 1 (e.g., steelhead trout, coho salmon, and chinook salmon) and their habitat. Beginning in 1996, the National Marine Fisheries Services (NMFS) and the California Department of Fish and Game (DFG) listed steelhead trout, coho salmon, and chinook salmon as threatened under the federal Endangered Species Act (ESA) and the California Endangered Species Act (CESA), respectively. In 2005, the coho salmon s status was upgraded from threatened to endangered on both the ESA and the CESA lists. A number of factors led to the decline of anadromous salmonid populations in the policy area. Climatic variation, disease, predation, loss of genetic diversity, fish harvesting, and land and water use all pose an ongoing threat to salmonids. Degradation and loss of freshwater habitat is one of the leading causes for the decline of salmonids in California (DFG, 2004). Historical and continuing urban, agricultural, and timber harvest land use practices affect fish habitat by increasing pollutant loading and causing sedimentation of spawning gravels. Land use practices also result in removal of riparian habitat and physical alteration of stream channels, including the creation of barriers to fish migration. Water diversion results in a significant loss of fish habitat in California (NMFS, 1996). Water withdrawals change the natural hydrologic patterns of streams and can directly result in loss or reduction of the physical habitat that fish occupy. Flow reduction can exacerbate many of the problems associated with land use practices by reducing the capacity of streams to assimilate pollutants. Construction and operation of dams and diversions create barriers to fish migration, thereby blocking fish from access to historical habitat. Dams also disrupt the flow of food (i.e., aquatic insects), woody debris, and gravel needed to maintain downstream fish habitat. 1 The first usage of terms defined in the Glossary of Terms (Appendix I) is indicated in bold. The SWRCB determined that some water users may choose to extract groundwater instead of pursuing a surface water diversion license under the Policy. The SWRCB explored the potential impact of groundwater extraction on streams in the Policy Area by hiring contractors. In February 2008, Stetson Engineering, under a contract with the SWRCB, published a technical memorandum entitled; Approach To Delineate Subterranean Streams and Determine Streamflow Depletion Areas. The opening paragraphs of this technical memorandum are quoted below. The State Water Resources Control Board s (State Water Board) adoption of the Policy for Maintaining Instream Flows in Northern California Coastal Streams (Policy) may result in some water diverters choosing to divert groundwater instead of pursing a water right application to divert water from surface streams. Groundwater diversions can have similar effects on the depletion of surface flow as diversions from surface streams. Thus, increased groundwater pumping could have a negative effect on the instream flows and anadromous fish habitat in the policy area if a hydraulic connection exists.

13 Dunphy Vineyard February 11, 2011 Page 13 of 31 Pursuant to Water Code 1200, the State Water Board has permitting authority over subterranean streams flowing in known and definite channels. Groundwater classified as percolating groundwater is not subject to the State Water Board s permitting authority. Thus, when considering an appropriation of groundwater, the State Water Board may have to evaluate the legal classification of the groundwater and determine whether it is a subterranean stream subject to the State Water Board s permitting authority. In doing so, the State Water Board applies a four-part test, which was uphold by the appellate court in North Gualala Water Co. v. State Water Resources Control Bd. (North Gualala) (2006) 139 Cal.App.4th 1577 [43 Cal.Rptr.3d 821]. The State Water Board also has continuing authority to protect public trust uses and to prevent the waste, unreasonable use, unreasonable method of use, or unreasonable method of diversion of water, regardless of basis of right. This technical memorandum provides an approach: (1) to delineate subterranean streams in accordance with the State Water Board s four-part test; and (2) to delineate areas (Potential Stream Depletion Areas) where groundwater pumping could potentially cause stream depletion. The identification of Potential Stream Depletion Areas (PSDA) is not intended as a substitute for the State Water Board s classification of groundwater; instead, identification of a PSDA may be used to assess impacts of groundwater pumping on instream flows and habitat. New information and site specific studies may in the future, result in some PSDA being classified as subterranean streams. The named groundwater basins/areas in the Policy area are listed in Table 1. Page 3 of the Stetson Engineering technical memorandum (2008) provides this operational definition of Subterranean Streams. DELINEATION OF SUBTERRANEAN STREAMS In determining the legal classification of groundwater, the following physical conditions must exist for the State Water Board to classify groundwater as a subterranean stream flowing through a known and definite channel: (1) A subsurface channel must be present; (2) The channel must have a relatively impermeable bed and banks; (3) The course of the channel must be known or capable of being determined by reasonable inference; and (4) Groundwater must be flowing in the channel. Where the above physical criteria can be clearly applied, the subterranean stream may be identified using published resources and approaches as discussed below. By the above definition, subterranean streams are corridors of more permeable material than the surrounding material. Water moving as underflow of a stream or in the hyporheic zone surrounding a stream are examples of subterranean streams. However, groundwater extracted from the alluvium surrounding a subterranean stream can also impact the flow in the associated surface stream. The older alluvium surrounding a stream is called a Potential Stream Depletion Area (PSDA). Page 5 of the Stetson technical memorandum (2008) discusses the operational definition of PSDAs. STREAM DEPLETION WHERE SUBTERRANEAN STREAMS ARE NOT DELINEATED In the Policy area where streams and adjacent alluvial aquifers are hydraulically connected, groundwater pumping threatens streamflow by depletion. Stream depletion from wells can result from direct depletion of the stream or reduction of groundwater flow to the stream. Groundwater moves laterally from older alluvial deposits to the stream channel deposits and is then discharged to the stream as baseflow. Wells pumping from the older alluvial deposits will intercept groundwater moving toward the stream which may ultimately discharge to the stream. Where

14 Dunphy Vineyard February 11, 2011 Page 14 of 31 geologic maps indicate or infer the presence of older alluvium (or equivalent deposits), the location and nature of the bed and banks becomes uncertain. Therefore, along stream reaches where geologic map information is currently insufficient to definitively delineate bed and banks (subterranean stream), but extraction of groundwater can potentially deplete streamflow, Potential Stream Depletion Areas (PSDA) will be delineated. New information and site specific studies may result in some PSDA being classified as subterranean streams. The areal extent of stream channel deposits of an active natural stream within a PSDA, as mapped by the USGS or CGS, will be indicated on the maps prepared for the Policy area. These deposits typically occupy all or a portion of the stream floodplain and were deposited by the stream. Pumping from these deposits are likely to result in depletion rates higher than rates resulting from pumped wells located elsewhere in a PSDA. A schematic diagram showing the relationship between subterranean streams, PSDA and stream channel deposits is shown in Figure 2. The result of the 2008 Stetson technical memorandum was the creation of a set of 7.5-minute maps showing PSDA and subterranean streams in the Policy Area. Dry Creek, in the vicinity of the Dunphy project, is on the Napa Potential Stream Depletion Area quadrangle (attached). The entire Napa Potential Stream Depletion Area quadrangle measures 24 inches by 36 inches so, Figure 7 shows the vicinity of the Dunphy project which is in the northwest corner of the Napa quadrangle. Figure 7 also contains most of the legend of the Potential Napa Stream Depletion Area quadrangle. The maps of the Stream Depletion Areas are also provided in the form of GIS shape and layer files. Figure 8 shows the outline of the Dunphy parcel, as per the Napa County GIS files, along with the Potential Stream Depletion Areas. Relationship between the Dunphy well and the PSDA According to the California Geological Survey (CGS) geologic map of the Napa 7.5-minute quadrangle (Clahan et. al., 2004), the ground surface at the Dunphy well is in the Great Valley Sequence. The County has not entered the well driller log for the Dunphy well into the project record so it is unknown if the well intersects formations other than the Great Valley sequence. The legend of the CGS map describes the Great Valley Sequence as follows: Great Valley Sequence (early Cretaceous and late Jurassic) - Sandstone, pebble conglomerate, siltstone, and shale. In December 1975, the California Department of Water Resources (DWR) published Evaluation of Groundwater Resources: Sonoma County, Bulletin 118-4, Volume I, Geologic and Hydrologic Data. That publication provides the following discussion of well yield of the Great Valley sequence and the Franciscan which together they refer to as Jura-Cretaceous rocks. Well Yield. Ground water is present in the Franciscan and Great Valley Sequence rocks as indicated by the great number of springs in the areas of outcrop (see Figure 18). Ground water is not present in primary openings, as with the water-bearing materials, but rather in secondary openings such as joints, fractures, and shear zones. Wells drilled in these rocks frequently are completed as "hard rock" wells; that is, they usually are uncased. Well yields generally are low and range from less than 1 to at most 3 gpm (<4 to 12 liters/minute). These meager yields, however, may be sufficient for domestic purposes provided that water storage facilities of at least 1,000 gallons (3.78 m 3 ) are available. Well log data are available from 27 wells drilled into the Jura-Cretaceous rocks. These wells range in depth from 20 to 257 feet (6 to 78 meters); the range of yield of water is from 0.2 to 68 gpm (0.7 to 257 liters/minute), with the average being 18.4 gpm (70 liters/minute). Static water levels ranged from 2 feet to 160 feet (0.6 to 48.7 meters); one well was reported as flowing. An indication of the ability of a "hard rock" well to yield water is its discharge per unit of saturated rock. For wells

15 Dunphy Vineyard February 11, 2011 Page 15 of 31 in the Jura-Cretaceous rocks, this value ranged from 0.01 to 1.5 gpm per foot (0.1 to 18 11m per meter); the average was 0.22 gpm per foot (2.7 liters/minute per meter). (Emphasis Added) See the preceding section of this letter entitled A Brief Discussion of Groundwater for definitions of the terms joints, fractures and shear zones. The above quote, from DWR s Volume I of Bulletin 11-4, of the discussion of well yield shows that DWR believes that the Great Valley sequence is similar to the Franciscan in regards to the movement of groundwater and well yield. DWR would expect similar well yields from well drilled in either the Great Valley sequence or in Franciscan. Groundwater in the Great Valley sequence, that is available to a well, is found in secondary openings such as joints, fractures and shear zones. The specific capacity (well discharge divided by drawdown in the well) of wells completed in Jura-Cretaceous rocks ranged from 0.01 to 1.5 gpm/foot. The specific capacity of the Dunphy well, based on the short duration 2004 pump test, is 4.2 (25 gpm/6 feet of drawdown). The specific capacity of the Dunphy well (4.2 gpm/ft) is more than twice as great as the largest reported specific capacity for Jura-Cretaceous rock (1.5 gpm/ft), as reported in Bulletin Volume 1 (1975). This suggests that the Dunphy well is drawing water from the alluvium through the fractures, joints or shear zones in the Great Valley sequence. The 2004 CGS geologic map of the Napa quadrangle also shows that there is a concealed fault between the Dunphy parcel and Dry Creek see Figure 6. The map shows the concealed fault is about 250 feet to the northeast of the Dunphy well, in the alluvium. The map shows the concealed fault crossing to the west side of Dry Creek Road south of the Dunphy parcel. The revised IS/MND for the Dunphy project does not mention this fault. The revised IS/MND is incomplete because it does not consider the presence of the concealed fault. The discussion of faults in the revised IS/MND dated January 14, 2011 is quoted below. VI. GEOLOGY AND SOILS. Discussion: a.i-iii The project site is not located within the Alquist-Priolo Earthquake Fault Zone. The nearest fault, the West Napa Fault is located approximately 2,500 feet to the east, and two active faults are located over 2,500 feet to the south of the project site14. No faults, scarps, or other indications of active fault zones were recognized through field visits. The project would result in no impacts with respect to fault rupture. There is a high potential for strong ground shaking throughout the entire San Francisco Bay and Napa County areas. The project is located in an area of very low hazard from liquefaction. The project would not involve the construction of new structures that would result in risk of loss or injury. These impacts are considered less than significant. The fault is mapped as a concealed fault because it is buried by the Pleistocene alluvium (mapping symbol Qpa). According to Bates and Jackson (1984) the Pleistocene is an epoch of the Quartenary period, It began two to three million years ago and lasted until the start of the Holocene some 8,000 years ago. The mapped fault is in the rock below the alluvium. The fault is probably at the intersection of the Great Valley sequence, on the west side of the fault, and the Sonoma Volcanics, on the east side of the fault. There has been no movement along a mapped concealed fault since the alluvium was deposited. If there had been movement along the fault after the alluvium was deposited then there would be indications of the existence of the fault at the ground surface. The lack of evidence of the fault along the ground surface means that the authors of the geologic map had to infer the location of the fault. The concealed fault has not affected the alluvium since the fault has not moved since the alluvium was deposited. The concealed fault does not affect the flow of groundwater through the alluvium. The concealed fault does not affect the flow of groundwater through the alluvium because the fault has not changed the alluvium in any way (Dr. Robert Curry, Registered Professional Geologist, personal communication).

16 Dunphy Vineyard February 11, 2011 Page 16 of 31 If there is a hydraulic connection between the Dunphy well and the alluvium then, the presence of the concealed fault, mapped between the Dunphy well and Dry Creek, will not affect the flow of groundwater either from the Dunphy parcel in the Great Valley sequence towards Dry Creek, or from Dry Creek towards the Dunphy well when it is pumping. Figure 6 shows the Dunphy parcel on the CGS geologic map of the Napa 7.5-minute quadrangle. The entire Dunphy parcel is to the west of the concealed fault and is mapped as Great Valley sequence. The Sonoma Volcanics lie to the east of the concealed fault, below the alluvium. A fault is the result of relative movement of the geologic material on opposite sides of the fault (see the definitions in the previous section of this letter). The movement along a fault fractures consolidated bedrock but would not fracture unconsolidated material such as alluvium. The area of fractured rock extends (shear zone) some distance to each side of the fault. The number of fractures per unit volume, in bedrock, is greater within the shear zone surrounding a fault than in the main body of the solid rock away from the shear zone. Fetter, (Applied Hydrogeology, 1980) gives a discussion of the relationship between faults and groundwater flow. A portion of that discussion follows: Fault zones can act as either barriers to groundwater flow or as groundwater conduits, depending on the nature of the material in the fault zone. If the fault zone consists of finely ground rock and clay (gouge), the material may have a very low hydraulic conductivity. Significant differences in groundwater levels can occur across such faults. Impounding faults can occur in unconsolidated materials with clay present, as well as in sedimentary rocks where interbedded shales, which normally would not hinder lateral groundwater flow, can be smeared along the fault by drag folds. In consolidated rocks, faults are more often groundwater conduits. Broken and brecciated rock in the fault zone may have a high porosity and hydraulic conductivity. Water may move along a fault to discharge as a spring. The 2004 CGS geologic map legend (figure 6) describes the mapping unit, containing the Dunphy parcel, as: KJgv Great Valley Sequence (early Cretaceous and late Jurassic) - Sandstone, pebble conglomerate, siltstone, and shale. The presence of shale in the Great Valley sequence suggests that the concealed fault, under the alluvium, between the Great Valley sequence and the Sonoma Volcanics may be a barrier to groundwater flow between the Sonoma Volcanics and the Great Valley sequence. However, the concealed fault does not impact the lateral flow of groundwater in the overlying alluvium. The Dunphy well is only about 250 feet away from the mapped location of the concealed fault therefore; it is likely that the fractured area surrounding the fault extends to the Dunphy well or past it. Such fractures would result in a greater yield to the Dunphy well than would be expected if the well was outside of the fault shear zone. As discussed above, the specific capacity of the Dunphy well (4.2 gpm/ft) is more than twice as great as the largest reported specific capacity for Jura-Cretaceous rock (1.5 gpm/ft), as reported in Bulletin Volume 1 (1975). The unexpectedly high specific capacity of the Dunphy well supports the hypothesis that the Dunphy well is within the shear zone of the concealed fault. The fractures in the shear zone of the concealed fault have the potential to provide a hydraulic connection between the Dunphy well and the alluvium of the PSDA. Farrar and Metzger (Ground-Water Resources in the Lower Milliken Sarco Tulucay Creeks Area, Southeastern Napa County, California, , 2003) consider the Great Valley sequence to be relatively impermeable compared to either the Sonoma Volcanics or to alluvial deposits (page 10). Rocks in the Great Valley sequence and Franciscan Complex are highly lithified and generally of low permeability. In other areas of northern California, these geologic assemblages generally provide only small quantities of water to wells. The Great Valley sequence or Franciscan Complex

17 Dunphy Vineyard February 11, 2011 Page 17 of 31 Figure 6. The northwest corner of the geologic map of the Napa 7.5-minute quadrangle created by the California Geological Survey, 2004, showing the approximate location of the Dunphy parcel. The geologic map legend is continued on the next page. The Dunphy well is located in the northern tip of the parcel. A concealed fault lies to the east of Dry Creek Road, between the road and Dry Creek in the vicinity of the well. The Dunphy parcel is to the west of Dry Creek Road.

18 Dunphy Vineyard February 11, 2011 Page 18 of 31 Figure 6 Continued. The legend of the geologic map of the Napa 7.5-minute quadrangle created by the California Geological Survey, 2004.

19 Dunphy Vineyard February 11, 2011 Page 19 of 31 Figure 7. The northwest corner of the Stream Depletion Map of the Napa 7.5-minute quadrangle is shown. The original Napa quadrangle Stream Depletion Map measures 24 inches by 36 inches and is attached to this report. A portion of Dry Creek near the Napa River is on the Yountville 7.5-minute quadrangle.

20 Dunphy Vineyard February 11, 2011 Page 20 of 31 Figure 8. The Stream Depletion map in Figure 5 was overlain on a 7.5-minute topographic map showing the location of the Dunphy parcel. The cross-hatched areas are Potential Stream Depletion Areas. The stippled areas are mapped stream channels and associated alluvial gravels within Potential Stream Depletion Areas, wells pumping from these areas are likely to result in greater and more immediate stream depletion.

21 Dunphy Vineyard February 11, 2011 Page 21 of 31 form the bottom boundary of the ground-water basin in the study area because the rocks in these assemblages are relatively impermeable compared with the rocks of the Sonoma Volcanics and sediments in the Quaternary alluvial deposits. Farrar and Metzger (2003) expect the Great Valley sequence to provide only small quantities of water to wells. The LSCE letter dated February 7, 2011 and entitled Investigation of Geologic Conditions, Dunphy Vineyard Project, Napa County discusses geology of the area around the Dunphy parcel, including the concealed fault between the Dunphy property and Dry Creek. The February 7, 2011, letter from LSCE, also discusses the well driller s log for the Dunphy well, an important piece of information that the County only recently obtained. The LSCE February 7, 2011 letter describes the geology as follows. Geologic Conditions The local geologic conditions for the area in the vicinity of the Dunphy property are characterized by the Great Valley Sequence overlain by a veneer of clay and fine-grained material, located west of Dry Creek Road. Northeast of the Dunphy property toward Dry Creek, the geology is characterized by the Sonoma Volcanics overlain by a thick sequence (80 feet or greater) of clay and other fine-grained material. A fault, located generally along Dry Creek Road, separates the Great Valley Sequence from the clay and Sonoma Volcanics. Dry Creek is underlain by the clay and fine-grained material east of the fault and the Dunphy property. East of the fault toward Napa Valley, the fine-grained material that overlies the Sonoma Volcanics transitions into alluvium with a greater amount of coarsegrained material, making the alluvium in this area a groundwater-producing unit that is pumped by many wells. The LSCE letter does not mention that the fault along Dry Creek Road is a concealed fault, see Figure 6. The fault is considered concealed because it is buried beneath the Pleistocene alluvium (Qpa). As discussed above, the concealed fault will not affect the flow of groundwater through the alluvium since there has been no displacement of the alluvium due to past movements of the fault. The LSCE February 7, 2011 letter characterizes the alluvium (Qpa) as being greater than 80 feet thick and consisting of clay and other fine-grained material. The legend of the 2004 CSG Geologic map, shown in Figure 6, characterizes the Qpa mapping unit as: Alluvium, undivided (latest Pleistocene) - Alluvial fan, stream terrace, basin, and channel deposits, composed of poorly to moderately sorted sand, silt, clay, and gravel So, the alluvium between the Dunphy well and Dry Creek is characterized by a mixture of fine-grained and coarse-grained material. The hydraulic conductivity of a given segment of the alluvium can not be predicted from a geologic map. The poorly sorted material would have a low hydraulic conductivity but the moderately sorted material would have a moderate hydraulic conductivity. The presence of channel deposits suggests there could be local areas with relatively high hydraulic conductivity. To recap, neither the concealed fault nor the Pleistocene alluvium (Qpa) between the Dunphy well and Dry Creek can be expected to act as a barrier to lateral groundwater flow either from the Dunphy parcel towards Dry Creek or from Dry Creek towards the Dunphy well. The February 7, 2011 LSCE letter continues: Wells located at the Dunphy property and neighboring properties are screened or perforated in the Great Valley Sequence (Dunphy) or if located east of the fault, in the Sonoma Volcanics under

22 Dunphy Vineyard February 11, 2011 Page 22 of 31 confined conditions. Confined conditions are produced by the occurrence of the surgical clay and fine-grained materials that form the upper portion of the Great Valley Sequence and overly the Sonoma Volcanics. Dry Creek is located northeast of the Dunphy property, and in this area there were isolated pools identified by Napa County during the Summer and Fall of The presence of these isolated pools in Dry Creek during the portion of the year when there is not any measureable streamflow are likely the result of the underlying clay and fine-grained materials restricting downward percolation of water. There may be clay and fine-grained material underlying Dry Creek. However, the PSDA map produced by Stetson Engineering for the SWRCB (see Figures 7 and 8) shows the area between the Dunphy well and Dry Creek as a Potential Stream Depletion Area (PSDA). The operation definition of a PSDA states that: STREAM DEPLETION WHERE SUBTERRANEAN STREAMS ARE NOT DELINEATED In the Policy area where streams and adjacent alluvial aquifers are hydraulically connected, groundwater pumping threatens streamflow by depletion. Stream depletion from wells can result from direct depletion of the stream or reduction of groundwater flow to the stream. Groundwater moves laterally from older alluvial deposits to the stream channel deposits and is then discharged to the stream as baseflow. Wells pumping from the older alluvial deposits will intercept groundwater moving toward the stream which may ultimately discharge to the stream. Where geologic maps indicate or infer the presence of older alluvium (or equivalent deposits), the location and nature of the bed and banks becomes uncertain. Therefore, along stream reaches where geologic map information is currently insufficient to definitively delineate bed and banks (subterranean stream), but extraction of groundwater can potentially deplete streamflow, Potential Stream Depletion Areas (PSDA) will be delineated. New information and site specific studies may result in some PSDA being classified as subterranean streams. (Emphasis Added) The above operational definition of a PSDA recognizes that: Groundwater moves laterally from older alluvial deposits to the stream channel deposits and is then discharged to the stream as baseflow. Wells pumping from the older alluvial deposits will intercept groundwater moving toward the stream which may ultimately discharge to the stream. Therefore, wells drawing water from the alluvium (Qpa) between the Dunphy well and Dry Creek are assumed to be intercepting groundwater moving towards Dry Creek and which may ultimately discharge to the creek. I have presented evidence above that supports the hypothesis that the Dunphy well is in hydraulic connection with the PSDA (older alluvium, Qpa). The February 7, 2011 from LSCE provides the following description of the Dunphy well. The geologic conditions at the Dunphy property consist of clays, shales, and rocks characteristic of the Great Valley Sequence. The irrigation well on the Dunphy property is perforated from 30 to 170 feet 1 and pumps groundwater from shale and undifferentiated rocks as described on the DWR Drillers Report for the well. The drillers report indicated that water was first encountered at a depth of 85 feet and subsequently rose to a depth of about 30 feet below ground surface, which implies that confined conditions exist in the Great Valley Sequence and in the interval the Dunphy well pumps from. These observations were made during the drilling and construction of the well. 1 The drillers report acquired by Napa County through DWR reported the perforation interval of the Dunphy well from 30 to 70 feet and gravel pack from 27 to 170 feet. A follow up conversation with the drilling company representative who drilled the Dunphy well indicated that there was a typographical error and that the perforated interval should have read 30 to 170 feet (personal communication, February 2, 2011) to be consistent with the gravel pack interval.

23 Dunphy Vineyard February 11, 2011 Page 23 of 31 The edge of the PSDA (alluvium) is about 112 feet to the northeast of the Dunphy well and the ground surface elevation at this point between the 180 feet and 185 feet contour lines. The top of the perforations in the Dunphy well is 30 feet below the ground surface (about 190 feet). So, the elevation of the top of the perforations is 160 feet and the elevation at bottom of the perforations is about 20 feet above sea level. The top of the perforations (160 feet elevation) are about 20 feet below the ground surface at the edge of the PSDA (about 180 feet elevation). An estimate of the depth of the alluvium between the Dunphy well and the concealed fault would give an indication of the thickness of the alluvium that might be in range of the perforations in the Dunphy well. The depth of the alluvium above the fault is unknown. A rough estimate of the depth of the alluvium above the fault can be made by assuming that the slope of Great Valley sequence is the same below the alluvium as above the alluvium. The Dunphy well is located in the ravine of a Class III watercourse so I used the slope of the ground about 165 feet to the south of the well to estimate the slope of the Great Valley sequence. I measured that the horizontal distance between the 290 foot contour line and the 190 foot contour line was about 270 feet. So, the slope of the Great Valley sequence, near the Dunphy well, is 37% (= 100 x ( )/270 ). The approximate distance from the edge of the alluvium, near the Dunphy well, to the fault is about 138 feet (250 feet 112 feet). So the depth of the alluvium is roughly 50 feet (51 feet = 138 feet x 37%). The elevation of the ground surface at the edge of the alluvium is about 180 feet. Subtracting the 50 feet for the depth of the alluvium gives an elevation of the bottom of the alluvium, over the concealed fault, of roughly 130 feet above sea level. The elevation at the top of the perforations in the Dunphy well is about 160 feet. Therefore, it is likely that the upper 30 feet (= 160 feet 130 feet) of the perforations are opposite the alluvium in the PSDA. This is a rough estimate and should be verified by direct measurement or by the examination of well driller reports which I do not have access to since they are proprietary in California. Past displacement along the concealed fault has likely fractured the Great Valley sequence surrounding the Dunphy well. These fractures have a potential to provide a hydraulic connection between the well and the alluvium of the PSDA. I have presented a fair argument that it is likely that the Dunphy well is hydraulically connected to the alluvium but only direct measurement, such as a 72-hour constantdischarge pump test, can prove that a hydraulic connection actually exists. If the Dunphy well is hydraulically connected to the alluvium then it can draw water from the alluvium (PSDA). The February 7, 2011 LSCE letter concludes, in the quote below, that the Dunphy well will not have a significant influence on neighboring wells or Dry Creek. The analysis I presented above demonstrates that these conclusions are not justified. The geologic conditions that are present at the Dunphy property and in the area northeast of the property towards Dry Creek suggest that the operation of the Dunphy well will not have a significant influence on groundwater levels on neighbor wells which are separated from the Dunphy property by the fault and are completed in a different geologic formation (the Sonoma Volcanics). The likelihood of the Dunphy well having an effect on Dry Creek is considered even more remote given the occurrence of the fault and the presence of the thick sequence of clay and fine-grained materials that underlie Dry Creek and separate Dry Creek from the primary units which the wells in the area pump groundwater (including the Dunphy well). Neighboring wells that are completed in the Great Valley sequence to the west of the concealed fault could be directly impacted by the operation of the Dunphy well depending on the distribution of fractures in the rock. Dry Creek and wells to the east of the concealed fault that draw all or a portion of their water from the alluvium may also be impacted by the pumping of the Dunphy well, if they are within the radiusof-influence of the Dunphy well.