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HomeMy WebLinkAbout11 Attachment 1 - MVGB 2020-2021 Annual Report_Final/7) GE1 XConsullants Consulting Engineers and Scientists Annual Report for the Martis Valley Groundwater Basin Water Years 2020 and 2021 June 2, 2022 �TRUCKEE DONNER PUBLIC UTILITY DISTRICT A 06 PCWA �1 GEI Consultants Consulting Engineers and Scientists Martis Valley Groundwater Basin Annual Report Water Years 2020 and 2021 Prepared for: Truckee Donner Public Utility District On behalf of Truckee Donner Public Utility District, Northstar Community Service District, and Placer County Water Agency collectively referred to as the MVGB Agencies. Prepared by: GEI Consultants 2868 Prospect Park Drive, Suite 400 Sacramento, CA 95670 June 2, 2022 TRUCKEE DONNER PUBLIC UTILITY DISTRICT MARTIS VALLEY GROUNDWATER BASIN ANNUAL REPORT WATER YEARS 2020 AND 2021 Certifications and Seals This report and analysis was prepared by the following GEI Consultants Inc. professional geologists. Report sections contained herein based on available data and were prepared by: Date: June 2, 2022 S Storey Geologist -In -Training No. 812 Date: June 2, 2022 Richard W. Shatz Principal Hydrogeologist California Certified Hydrogeologist C.H.G. No. 84 Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 i Table of Contents Tableof Contents.....................................................................................................................................................ii ExecutiveSummary.................................................................................................................................................1 1. Introduction....................................................................................................................................1 1.1 Martis Valley Groundwater Basin........................................................................................1 1.2 Climatic Conditions.............................................................................................................2 1.3 Surface Water Conditions...................................................................................................2 2. Groundwater Conditions...............................................................................................................7 2.1 Groundwater Levels............................................................................................................7 2.2 Groundwater Flow.............................................................................................................13 3. Groundwater Extraction..............................................................................................................18 4. Surface Water Diversions...........................................................................................................25 5. Groundwater Recharge...............................................................................................................27 6. Total Water Use............................................................................................................................28 7. Change in Groundwater Storage................................................................................................29 8. Groundwater Management Activities.........................................................................................35 9. Conclusions.................................................................................................................................36 10. References....................................................................................................................................37 Attachment A. Monitoring Well Hydrographs.....................................................................................................38 Figures Figure 1 Martis Valley Groundwater Basin Location Figure 2 Annual Precipitation Deviation from Mean: Truckee Ranger Station No. 049343 Figure 3 Martis Valley Groundwater Basin Monitoring Well Locations Figure 4 Martis Valley Groundwater Basin Historic Groundwater Level Elevations, Water Years 1989-2021 Figure 5 Martis Valley Groundwater Basin Historic Groundwater Level Elevations, Water Years 2015-2021 Figure 6 Martis Valley Groundwater Basin Spring 2020 Groundwater Elevation Contours Figure 7 Martis Valley Groundwater Basin Fall 2020 Groundwater Elevation Contours Figure 8 Martis Valley Groundwater Basin Spring 2021 Groundwater Elevation Contours Figure 9 Martis Valley Groundwater Basin Fall 2021 Groundwater Elevation Contours Figure 10 Martis Valley Groundwater Basin Locations of Groundwater Extractions Figure 11 Martis Valley Groundwater Basin Community Water System Monthly Pumping Totals Figure 12 Martis Valley Groundwater Basin Change in Groundwater Elevation, Spring 2019-Spring 2020 Figure 13 Martis Valley Groundwater Basin Change in Groundwater Elevation, Spring 2020-Spring 2021 Figure 14 Change in Storage and Groundwater Use Tables Table 1 Groundwater Extractions for Water Year 2019-2020 Table 2 Groundwater Extractions for Water Year 2020-2021 Table 3 Surface Water Usage Reported for Water Year 2019-2020 Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 ii Table 4 Surface Water Usage Reported for Water Year 2020-2021 Table 5 Estimated Groundwater Recharge from T-TSA for Water Years 2019-2020 Table 6 Estimated Groundwater Recharge from T-TSA for Water Years 2020-2021 Table 7 Total Water Use for Water Years 2020-2021 Table 8 Estimated Change in Storage Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 iii Executive Summary This report provides annual monitoring data and an assessment of groundwater conditions in the Martis Valley Groundwater Basin (MVGB or Basin) for water years 2020 and 2021. A water year (WY) is defined as October through September of any year. The MVGB does not have to comply with the Sustainable Groundwater Management Act, as the Basin was re-classified in 2018 as a very low priority basin. However, the MVGB Agencies recognize the importance of groundwater management and are continuing to implement their 2013 Groundwater Management Plan. Groundwater levels, groundwater extractions, surface water conditions, groundwater recharge from locally derived and imported wastewater, measured and estimated total water use and groundwater storage change estimates were compiled and analyzed. Climatic conditions were also evaluated as to their effects on groundwater levels. Both WYs 2020 and 2021 have been classified as dry years based on precipitation with WY 2021 being the driest on record. In WY 2021, rainfall was less than 50 percent of normal rainfall. Groundwater levels throughout the Basin decreased due primarily to the lack of precipitation recharging the aquifers and increases in groundwater pumping in response the extremely dry conditions. Most wells remained above their lowest measured groundwater levels in WY 2020 and 2021, except for three wells during the dry summer months of each water year. The historical record for these wells is limited and in recent years the participating agencies have substantially increased the number of reporting wells and intervals of measurement The detection of the groundwater levels exceeding the lowest levels previously recorded would not have been detected without the Agencies increasing groundwater level monitoring frequency to a monthly basis. Groundwater pumping in the Basin increased by about 10 percent, about 800 acre-feet (average), during these water years in comparison to previous years (average from 2016 through 2019). Change in groundwater storage values reflected the extremely dry conditions and moderate increase in pumping, and overall groundwater in storage decreased by about 17,000 acre-feet (AF) over the last two WYs. Most groundwater basins in northern California experienced decreases in storage during these two WYs. The average annual groundwater pumping over this two-year period was approximately 7,400 AF, much less than the sustainable yield of 22,000 AF per year, which suggests that the long-term groundwater levels and storage will recover after above normal and wet precipitation year(s). The Basin storage has been conservatively estimated to be about 484,000 AF so the overall change over the last two years is relatively small (about 3.5%) in comparison to the total water stored in the Basin. Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 ES-1 1. Introduction The Martis Valley Groundwater Basin (MVGB or Basin) groundwater resources have been evaluated for many years starting in the 1990s. In 2013, a Groundwater Management Plan (GMP) was developed for the Basin (Brown and Caldwell, 2013). In 2014, the Sustainable Groundwater Management Act (SGMA) classified the MVGB as medium priority basin, which required compliance with the SGMA regulations. In December 2016, an Alternative Submittal to a Groundwater Sustainability Plan was submitted to the California Department of Water Resources (DWR) by the Truckee Donner Public Utility District (TDPUD) on behalf its MVGB SGMA Local Agencies (MVGB Agencies), which include TDPUD, Northstar Community Services District (NCSD), Placer County Water Agency (PCWA), the Town of Truckee, Nevada County, and Placer County. As referenced in the MVGB Alternative Submittal, scientific analyses determined the Basin has at least a 25-year history of sustainable groundwater operations and conditions, despite several periods of drought. In compliance with SGMA requirements an Annual Report for water years (WYs) 2016 and 2017 were developed and submitted to DWR. Prior to DWR completing its review of the Alternative Submittal and Annual Reports, DWR was required to review basin prioritizations as part of implementation of SGMA. The MVGB Agencies reviewed DWR's initial prioritization of the Basin and worked extensively with DWR staff to ensure accurate information was being used. In 2018, DWR re-evaluated the Basin and changed its priority to Very Low Priority, thus the Basin was no longer required to comply with SGMA. The MVGB Agencies recognize the importance of groundwater management and have subsequently reconvened to implement the 2013 GMP. As part of this plan, Best Management Objective #1 is to compile an annual report to summarize groundwater conditions and to share the information with interested stakeholders. Since WY 2018, the MVGB Agencies have prepared annual reports and have shared them with stakeholders. This document provides a summary and interpretation of groundwater conditions for WY's 2020 and 2021, instead of just one WY, due to COVID restrictions. The report provides historical data for reference along with a more detailed assessment of the conditions since implementation of the GMP. 1.1 Martis Valley Groundwater Basin The MVGB, Basin No. 6-67, as defined by DWR in Bulletin 118 Interim Update (2016), is a 35,600-acre (57-square-mile) intermontane, fault -bounded basin east of the Sierra Nevada crest. Figure 1 shows the location of the MVGB and pertinent geographic features. The MVGB uses groundwater almost exclusively for water demands, although several major surface water bodies are present within the Basin. The Truckee River traverses the Basin from the southwest to the northeast in a shallow, incised channel. Principal tributaries to the Truckee River within the MVGB are Donner Creek, Martis Creek, and Prosser Creek; as well as discharge from Boca Reservoir slightly before the Truckee River leaves the Basin. Surface water storage reservoirs inside MVGB include Martis Lake and Prosser Reservoir. Donner Lake and Boca Reservoir lie just outside the MVGB boundaries, but release surface water into the MVGB. Although surface water released from reservoirs is not used to satisfy local demands, it is a major, and highly regulated, component of the Basin's hydrologic system. Surface water Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 1 within the MVGB is under the purview of the Truckee River Operating Agreement (TROA), a Bi-State, multi -party Federal Agreement enacted by the US Congress which sets limits on the consumptive use of both groundwater and surface water in the Basin. Wastewater is generated within the MVGB, within the Truckee River watershed, and outside the watershed (Lake Tahoe area) and sent to a treatment facility operated by the Tahoe -Truckee Sanitation Agency (T-TSA). The treated water is recharged into the groundwater system via two leach fields (Figure 1), increasing the groundwater contribution to downstream Truckee River flows. 1.2 Climatic Conditions Water year types were developed for the MVGB using local precipitation data from Truckee Ranger Station No. 049043. Its location is shown on Figure 1. WY 2020 was California's fifth driest year and WY 2021 is the second driest on record (DWR 2021). The average precipitation at the Truckee Ranger Station (1988-2019) was 29 inches while WY 2020 received only 18 inches and in WY 2021 only 14 inches, less than half of normal and the driest on record. The deviation of annual WY precipitation from the mean is shown on Figure 2. Wet conditions were set at more than one standard deviation above the mean annual WY precipitation total. Above normal conditions were defined as annual precipitation between the mean value and one standard deviation above it. Likewise, below normal conditions were defined as an annual precipitation between the mean value and one standard deviation below it. Dry conditions were defined as an annual precipitation total more than one standard deviation below the mean. WYs 2020 and 2021 are both classified as dry water years and have been the only back-to-back dry years reported during the period of record at the Truckee Ranger Station. Since precipitation is the major source of recharge in the Basin, groundwater levels responded by decreasing during the last two years. 1.3 Surface Water Conditions The Truckee River is the dominant hydrologic feature in the MVGB. It conveys hundreds of thousands of acre-feet (AF) of surface water through the Basin and flows along the lowest portions of the Basin. The measured outflow of the Truckee River at the edge of the Basin was about 385,000 AF in WY 2020, and only 290,000 AF in WY 2021. Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 2 Figure 1. Martis Valley Groundwater Basin Location J Flume, National Fore-,( 7 Rlag:il la P.0 adi se Sun Fall Re3ta - soca p seitiroir A- el Tah�•_lJ�tivnil _ F0 w . Grass ,I rep' C i Olivehwst El Djorado Lincoln Nmional South F_re.t Lake Roseville _ Taitn and Orangevate - 9 Fir O s 1F1 Dorado Fulls te` ac amento Elk Grove O 11 I r r � „«. Truckee Ranger I NEVADA , _ Precipitation Station (Station No:049043? /T-TSA Truckee River Leach I Fields I _ W" Creek - I f Donner Lake a ---- ------- iis-------------------------------- i Q Cr e Lake --- --- —i { //NEVADA COUNTY � I 1 PLACER COUNTY d I Precipitation E----------------------------------------------------------------------------�----------- ---------------- _ � �' � Station k Creeks and V V _ _ Rivers Northstar r Community Service District i I (NCSD) o - �,1� I r t Truckee -Donner C"IdCr �k ti . Public Utility F District (TDPUD) Martis Valley No'�_ hs�ar I Groundwater , Reno I Basin --- L — County Boundary - I Disposal Field C4" peeN Creek .^� 1tY ,r ` I D L 2 1 0 2 " Martin Valley Annual Report MARTIS VALLEY GROUNDWATER BASIN Water Year 2020 and 2021 W E Nevada and Placer Counties, California LOCATION Miles I s Truckee -Donner Public Utility District GE consultants APRIL 2022 FIGURE 1 V Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 3 [This page intentionally left blank.] Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 4 Figure 2. Annual Precipitation Deviation from Mean: Truckee Ranger Station No. 049343 35 30 25 20 a) a) t u c — 0 0 One Standard Deviation Q Above Mean u10 ----------------------------------------------------- a3 a ns as > 5 — c _0 0 +' 00 M O N rn -* Ln cp I-- 00 m O Iq ry rn e* Ln c0 co m O N N m Ln �0 n as m 0 ri ra 00 0o 0) Qi 0) T 0) a) a) (7) a) O Q Q O O O C. 0 O 4 -1 —1 —4 -1 N N 0) M m 01 M M M 0) 0) O O O O O O O O O O O O O O O O O O N N N N N N N N N N N N N N N N fV N -5 Below Normal -10------------------ - ---------------------------------------------- - - - - --- One Standard Deviation III Below Mean Dry -15 q -20 o" I Water Year Above Normal Ll Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 5 [This page intentionally left blank.] Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 6 2. Groundwater Conditions Wells used for groundwater level monitoring (labeled as CASGEM wells or piezometers) in the MVGB are shown on Figure 3. Groundwater levels at these wells are monitored by the MVGB Agencies and DWR and are reported to the California Statewide Groundwater Elevation Monitoring (CASGEM) program. These wells are used to help assess the sustainability of the MVGB. Data from the wells were used to generate hydrographs to show groundwater level elevation trends over time at each monitoring location. Groundwater levels in the Basin range from within a few feet of ground surface to as much as 100 feet below ground surface and have consistently remained within this range. Historically, groundwater level measurements were taken in the spring and fall. In 2017, the MVGB Agencies voluntarily implemented monthly monitoring of groundwater levels for all wells in the CASGEM program. This proactive move to monthly monitoring was, in part, to investigate and address uncertainties in seasonal variations. This evaluation continues to utilize spring and fall measurements to assess the health of the Basin, to show whether the basin has refilled in the spring, and the effects of pumping in the fall. Monthly groundwater measurements are illustrating that peak summer -time groundwater pumping temporarily lowers groundwater levels below the previous fall measurements, as would be expected, but are not depleting reserves. Because of climatic conditions groundwater levels may vary from year to year but should fully recover during above -normal to wet precipitation years. Three of the CASGEM monitoring wells (TH-Fibreboard, TH-Prosser Village, and TH-Martis Valley) are located near municipal supply wells that at times affect their measurements. Historically, it was not documented whether the nearby municipal wells were pumping or recently shut off when the measurements were taken. This has been corrected in recent years by shutting off the pumping wells for at least one -hour prior to taking a groundwater level measurement. In addition to the CASGEM wells, six temporary piezometers were constructed near Martis Creek for a restoration project and provided some additional information about the groundwater conditions in the Basin. In WY 2019, groundwater level measurements were discontinued at these piezometers. The MVGB Agencies' monitoring network has good regional distribution (covering over 70 percent of the Basin) and is monitoring groundwater levels near areas of pumping, inflow, and outflow. The network has 30 years of data that can be used to assess changes in the Basin and monitor aquifers that are being used for municipal and industrial purposes. 2.1 Groundwater Levels Long-term hydrographs, from 1989 through 2021 for all of the 14 monitoring wells, are presented on Figure 4 along with the water year types. Figure 5 provides a shorter time period than Figure 4 to further assess these seasonal variations in groundwater levels. Hydrographs for each individual monitoring well are presented in Attachment A. Based on spring to spring and fall to fall measurements, groundwater elevations, depending on the location in the Basin, are generally stable remaining within their historic ranges but some levels have decreased by Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 7 more than 10 feet over the last two years. This is expected due to both WYs being classified as dry with reduced recharge potential caused by less than 50 percent of normal precipitation and about 10 percent increase in pumping in response to the drought conditions. Local lowering of groundwater levels by this amount is not of concern as there is still over 800 feet of saturated sediments and the aquifers will likely recover after the next above normal to wet precipitation years. Seasonal fluctuations due to climate and pumping patterns are apparent. In general, spring groundwater levels decreased overall from 2019 to 2020 and fluctuated both directions from 2020 to 2021, primarily in response to decreased recharge due to the drought conditions. WYs 2020 and 2021 groundwater levels are all within their historical ranges except for two wells (Fibreboard TH and 18N17E33LO01) that fell below their historical fall lows in 2020 and 2021, by 18 and 0.6 feet, respectively. The larger drawdown at the Fibreboard TH is likely due to influence from the nearby municipal well. As shown by groundwater level measurements from the Fibreboard TH, obtained during 2020, groundwater levels recovered by more than 40 feet within two months of after pumping was stopped in the nearby municipal well, indicating this was not a permanent depletion of groundwater but a temporary and local effect of pumping. There were three wells that fell below their historical lows but these were during the summer months of both WYs when there was no historic monthly data to compare them to, including the previous drought years of 2012 to 2016 which likely would have recorded lower monthly groundwater levels. Groundwater levels in the Fibreboard TH monitoring well fell below fall historical lows by about 16 feet for 4 months in the summer of WY 2020, and 25 feet below the historical low in the summer of WY 2021 for 5 months. The Prosser Village TH monitoring well fell just below historical low in WY 2020 for 1 month and fell 9 feet below historical lows for 2 summer months in WY 2021. Well 18NI7E33LOO1M fell less than 1 foot below historic fall low for 3 months in WY 2021. These wells may be influenced by pumping at nearby municipal wells. Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 8 Figure 3. Martis Valley Groundwater Basin Monitoring Well Locations Su c$ek r} r % T 1 . i -I TDPLJD Municipal Well 'S+ Northstar {NCSD) Municipal Well f y GASGEM Well Shallow Piezometer � • � � � ' } -ft ev� Stream Stage Gage iBN18E22111001M ' .�' Greeks and Rivers It Marti$ Valley Groundwater Basin � r----r County Boundary - � � ,,, •r,�lr• *l r k 'nu F' HirsChdale r I I of r / t r I 18N17031-001M r Prosser _ Prosser Annex Village q ~�^• "' Village HlProsser 17N77E05Q001 01 t t Prosser 1 NEVADA Heights did Greenwood � �Fibreboard Well 020 i n ? ; 17N16E11F9 M TH-Fibreboard _ � I y Sanders�y Menshlre f r ,k Grivg 17N17E07P091M` { 3 Northside rir" 3 Q Southside Martis Valley 1TN17E18G091MI i —�~ 17N16E131t001M TH-M a rtis Valley t({>}rr> - . - c r l-ak' AIEVADA COUNT ! 17H16E17F002M'- -- J Opn r.Creek----`-- 17N16E13K003M I Ai�rt _— r------PLAGERGOUNTY' --- --- ` -^------_---_Ff--A 17N17E7 K907M v l i �■ I Well 3 % r ■ i Well ell? r171 29BO01M I c ' TiI'i 2 a� n ; Z ❑ 3 nWC'i' ek ❑■ - re � ■ uG lrC -� r TH1 17N77E298901M s MM267 _H 2.. ` TH.-Tast Hole; Prosser Villa a Maros Valle , and Fibreboard WElls have associated mu icl al -Wells 'nearby TDPUQ 2 1 0 2 Martis Valley Annual Report 1 MARTIS VALLEY GROUNDWATER BASIN Water Year 2020 and 2021 MONITORING LOCATIONS W - t' Nevada and Placer Counties, California Miles G E i Truckee -Donner Public Utility District Consultants APRIL 2022 FIGURE 3 3 Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 9 [This page intentionally left blank.] Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 10 Figure 4. 5,950 5,900 5,850 E r� _ 5,800 c 0 v w v 5,750 J L r� 3 c 5,700 0 l7 5,650 Martis Valley Groundwater Basin Historic Groundwater Level Elevations, Water Years 1989-2021 Monthly Measurements 17N16E17F002 M 17N17E29B001M 18N16E22H001M 17N16E11F001M 17N17E19K001M 17N17E07POO1M 17N17E18COO1M 18N17E33L001M 17N16E13KOO1M TH-Fibreboard TH-Prosser Village TH-Martis Valley 17N16E13K003M 17N17E05D001M ■ wet ■ Above Normal 5,600 0 Below Normal ■ ■■■■■ ■■ i I ■ ■• ■ ■ Dry ■ 0 No NONE 0 ■ ♦ water Year Start/End M o .4 N m -zt un Lo r' CO M o r.i m 'zt Ln �D n X m o r4 m 'zt un �O M M o op 01 01 M M M M m 0) m m O O O O O O O O O O ti ti N ti ti ti ti ry ry Q7 O� O1 01 Ol Ol Ql 6� 6� 6� 61 O O O O O O O O O O O O O O O O O O O O O O c-I c-I r-I r-I c-I c-I r-I r-I r-I r-I rl N N N N N N N N N N N N N N N N N N N N N N \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 0 0 0 0 0 0 0 0 0 o o 0 0 0 0 0 0 0 0 0 o o 0 0 o a o 0 0 0 0 0 0 Water Year Data collected from https://www.casgem.water.ca.gov Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 11 Figure 5. Martis Valley Groundwater Basin Historic Groundwater Level Elevations, Water Years 2015-2021 5,950 5,900 5,850 E T cr 5,800 c 0 c� v LU 5,750 v J N 3 5,700 0 u 5,650 5,600 OVA ►i[:1:1VAIII011AAI 17N17E29B001M 181\116E22H001M 17N16EI1F001 M 17N17E19K001M 17N17E07P001M 171\117E18C001M 18N17E33L001M 17N16E13001M TH-Fibreboard TH-Prosser Village TH-Martis Valley 17N16E13K003 M —17N17E05D001M ■ Wet ■ Above Normal 1 Below Normal ■ Dry 1P I 7�I I I 5,550 • ■ • . . A A ■ . ■ Water . • Start/End Year It It Ln Ln Ln L.o w �n �n Ln r- r- n w 00 00 00 rn rn rn rn 0 0 0 0 ti u 0 UJ Q o a u o �° O- 3 u a o 4. o a 3 u o C O- ,° a o Q 3 � a, u fl. o �° a 3 c`.i o O- a U o Month - Calendar Year Data collected from https://www.casgem.water.ca.gov Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 12 2.2 Groundwater Flow Seasonal groundwater level elevation contours for Spring and Fall 2020 through 2021 are shown on Figures 6 through 9. These contours reflect pumping, recharge, geologic conditions, and discharges to surface water. Monitoring well groundwater levels and bed elevations of gaining surface water reaches were used to develop the groundwater elevation contour maps. Groundwater levels at 17N16E13K003M were used for contouring as 17N 16E 13K001 M appears to reflect groundwater levels in a shallower portion of the aquifer. As expected, Fall season contours exhibit lower groundwater level elevations in the central portions of the Basin, relative to Spring conditions, due to increased pumping and less natural recharge. Spring contours for both years are similar, although at slightly different elevations, indicating recharge is reaching and refilling the aquifers despite the dry conditions during the summer months. The groundwater flow patterns remained generally the same during both water years, with flow from the perimeter of the MVGB towards the Truckee River, consistent with previous years. The groundwater contours show pumping has changed this regional pattern near the airport, but this is not a new development as the historical contours have also reflected this pumping depression. The pumping depression appears to be caused by the Martis Valley municipal well. The extent and depth of the depression has increased slightly because of the dry conditions of both WYs 2020 and 2021. Beginning in Fall 2020 a new pumping depression formed east of the town of Truckee and north of the Truckee River and remained through Spring and Fall 2021. Historically the contours showed discharges to the river, but with the lower groundwater levels due to drought conditions and the creation of a pumping depression, surface water may be discharging to groundwater in this area while the depression is present. The pumping depression appears to be the result of increased pumping from the Fibreboard, Prosser, and Old Greenwood wells. Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 13 Figure 6. Martis Valley Groundwater Basin Spring 2020 Groundwater Elevation Contours �'3.r c•1.r+1 Z� �� z a �P f• 49r1 +SN U22 1 eae�vrrrr l I� 5a21. t Y► - sse I J k rvoh' iI „ � $ r•„ram „i F f 18N17E33LD61M Hir$ch ale �r f TRU ICEEM;pNNER 17 ll P.U•E}• c' � ' 7N17E00m PrelssBr Pr sserAnnBsc 1 Village { _ J R TH-Prosser ilia d f i ► Prosser 572217 : • Crer•k Weights �elghts Fibr�bnard '� old Greenwood } ! well #Ztl i1iN16@11 FU61fYlIL a THfibrebo rd1 ,�. 4 �� 1 NEVADF ` r 82 5.4fi y° 5747. ` i- s - MARTIS f h Gt. nshire VALLEY Sanders 'i7N17F�1aclidiml 1 ,} 74.12 11A$IN ` Y r Ncrtt1 side / Y 17N17ED7P00 Epp- 5701.2 \5748.71 jij:rr•+cr f:rcCk � South WWI � i � albs Valley rra ----- J----- Dra+i ever fake ti f C 17N16E131�`0 3N' C r7ie iJEVADACOUNTY_—__-�_--- f 17N1BE17F0 2M Dann rCreek-- -_--+ 56& - _Airport _ ---- - -- - -- PLACER COUNTY -_--- -----------•-------_-•__�-----------____��____--------- �� �— � � � � � TDPt1D Municipal - 5TB �941 K0�'ItM Fuse ` Well 1 y - ! Well 3ell`i D Northstar (NCSD) Ty, T Municipal Well 4� CASGEM Well Groundwater Flow Direction Groundwater k R • "`�'c'ek >- � —Elevation Contours (f1 msi) Creeks and `s +� Rive rs Martis Valley Groundwater f�• +f*: •- Basin a ----- County Boundary s Martis Valley Annual Report MARTIS VALLEY GROUNDWATER BASIN a 1 0 2 Water Year 2020 and 2021 GROUNDWATER ELEVATION CONTOURS J w_*L. Nevada and Placer Counties, California SPRING 2020 Miles i Truckee -Donner Public Utility District GE consultants APRIL 2022 FIGURE 6 Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 14 Figure 7. Martis Valley Groundwater Basin Fall 2020 Groundwater Elevation Contours - r - �. „a� / � r 1BN16E22H 1 keseno-rr J 5819.18 . � . Sew l rasse Hirschdale 4 % r TREIEE:DDNNER Ru I P.U.O. I f 1BN17E331-00 58Oo 57,00 7,44.98 f+rosserAnna>r � 56�J0 T. -Prosser Vllla 17 k7� 5 U_6im 56 g 16.7 } Prosser }{_Ft r oaEd { C} Heights !j689 f Well m r'0 \, Fibreboard t _ se ers I/ ! � r' � � � MARTIS S ; 16E11F001M /17N17E18C041M 5850 600Q' —6000 5900 ft0 .OS VALLEY ' S739:82 1-� BASIN Narthside L 17iN17E07P00*d/ ouths3deMartis Valley 5747.01 711F1#617F002M TH-Maros Valley, a De ewr Lake 5687.2 } rru IMTY —_--- — T NEVABA 5$7 Airp3rt- -_- k" -----J-- --_- ---- ---- TDPUD Municipal _ _ — ---'*� — pLACER COUNTYWell _-_ -- -- ---J-----------T----- f----------------------- _ ocnyea "Creek —�- �- 5750� 580Q 1 17N17E19KK1M Northstar (NCSD) r-5�i17.7A_ 17F117E25B001M e°" •k ;+ Municipal Well '` r! 51;87 { ,/{ Well34.i� H1 �•• 5$00—07-1491QQ � '58ra0� ' ~' ! Monitoring Wells +f ? Groundwater _ Elevation 4 Contours Fall �= 2420 {ft mslJ Groundwater 2 Flaw Direction hti` r.c Creeks and o • Rivers m1W Mortis Valley } 10 Groundwater e Basin h County Boundary Martis Valley Annual Report NIARTIS VALLEY GROUNDWATER BASIN 2 1 0 2 Water Year 2020 and 2021 GROUNDWATER ELEVATION CONTOURS r w I: Nevada and Placer Counties, California FALL 2020 Miles a s Truckee Bonner Public Utility District E I [Qnsultants APRIL 2022 FIGURE 7 S Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 15 Figure 8. Martis Valley Groundwater Basin Spring 2021 Groundwater Elevation Contours r' t 4. , „gal 41 ° Tip 8NJfi r �UC[i 5819.1 Fi0 1 Resrrvn�r F � 5819.&8 .8 ... k 'rlwrr• -F TREJ 01 RILID. HER 5850 � � � kf C'it�i � � P.U.U. 57+50^ 5 g0 /1$'N17E331-00 - Prosser % /574213$� } Pr sserAnnex 11 Vilfage � rr r1 T -ProssepVillag. 17N17 t�5.., Q Y1' r 56 Pro+ ser Old Greenwood iir! J f [} 6000 Heighls • f504 Well#20 00 TH-FI6re6aar �17i11$E1F40157r' �# M r 0D �� ibrehoard 57��.1 I + ,. NEVAdA 0 5839:� f MARTIS � 1' I} � Gienshira'4 � any" ders�` 55800 Drive 71417E18G QiM VALLEY n .6000' r , / 5740,1e BASIN . n No itle a 7R001rM f I 17NiBE17F{t021�1 Sauthsii#e NTartis VallBy 5747.41 47.41 l - E 7�.5r 5850 �TH-Martin Valley 1 t (}llll t7f.'f Lr!!VP 5702.$ -- --T--- _— _ �. t Do Creek 17N E13K M NEVADAcOUNTY - 1 � Airport --- -- ---- - -- --- ---- -- J __—_______—_---------- _---___--- - - ---- --- - -P — 15850 -- 5SS�5: — _ L e PLACER COUNTY I' {:.• � TQPkJQ Municipal A _---- —_-- R— ---F 1 17M 191C FM Well ri n i; ` !VI r �� f"� 4-1N77E29B001M 8ua` k Northstar [NCSD) X / .05900 ? --y�3 II 1 `5850 t 3.77 Municipal Well . r Well I CASGEIM Well 2 X 590 T Groundwater _ Elevation Contours Spring 2427R s Groundwater e Flow Direction r _ C• Creeks and Divers 0 Martis Valley Groundwater Basin s * r iL .. , 1 Couniy Boundary r L--- I Martis Valley Annual Report NIARTIS VALLEY GROUNDWATER BASIN L 2 1 0 2 Water Year 2020 and 2021 GROUNDWATER ELEVATION CONTOURS L Nevada and Placer Counties, California SPRING 2021 MilesG E Truckee Donner Public Utility District consultants APRIL 2022 FIGURE 8 Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 16 Figure 9. Martis Valley Groundwater Basin Fall 2021 Groundwater Elevation Contours ti 4. .• do • - $ucv y je 18N-1 E22[� esenvrr. - I f - + �i r � rass h rtiviv „�- 5 60 r � r 5750 Hirsehdale �r 9 l / TRUCKEE —NE •. /..! r . C' ee l f • P.U.B. ( � �l • 5�00 00 N17E33LD 368 P rAnn. � � 5650 1 ■ T -P 4er Yllfa 171e7E 67 + Prosser fm-A r oar '-.0 r �� ar Heights 82. f � well420 r,•' F hreUoard f % ` NEVADA 6000� Sanders old t 1 MARTIS 5900N1fiE11F001M /�I73ti117E18C0 1M 5850 VALLEY ,6000 ,5"7%58 573GA2 BASIN 8000 Narthside 1 1TN17EVPU0fN!" 5uuthside Martis Valley 5745.51 7N1611 17F002M 5T50 5700 ? TFI Jlar#is Valley �., f}nrraer•Lrrke '17N--ur=13K0'6W& 56l34.8 i { r ` - ----- 'r+ COUNTY ----- ----- --- - ----- 1 Uonfer'Creek —_ 5668 0 Alipart-}__-- _ PLACER COUNTY _ - ------ - - - --f--- '5850� TDPUQ Municipal —____-__-- -------- -_---- � 17NI7:E,19K M 5800 Well 5 N 7E29BO 1 tlS` �k A}orthstar {<yCSDj $•4 Municipal Well Well 3� TH1 Monitoring Wells r r 5900 — 5900 5850 T 2 '? ? Groundwater Elevation y — Contours Fall P - - 2021 (ft msl) cj y" Groundwater Flow Direction Creeks and Rivers - +r Mortis Valley - Groundwater Basin a t' in — County Boundary 1 0 z Mantis Valley Annual Report MARTIS VALLEY GROUNDWATER BASIN Water Year 2020 and 2021 GROUNDWATER ELEVATION CONTOURS w' -- Nevada and Placer Counties, California Miles FALL 2021 a F x Truckee Danner Public Utility District ` Consultants APRIL 2022 FIGURE 9 Mantis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 17 3. Groundwater Extraction Groundwater extractions for various water use sectors are presented in Tables 1 and 2 for WYs 2020 and 2021, respectively. The methods used to measure extraction data are noted along with water use sector totals. The total water use is based on metered and estimated pumping. The general locations of the community water service areas and non -community water purveyors, along with the location of golf courses, are shown on Figure 10. Total groundwater extraction in the MVGB was about 7,160 and 7,670 AF for WYs 2020 and 2021, respectively, well below the sustainable yield estimate of 22,000 AF. Municipal groundwater extractions by TDPUD and NCSD, which are metered, account for about 80 percent of the total extractions; therefore, total groundwater extraction is well quantified. Groundwater extraction estimates for non -community uses and golf course irrigation were developed by others and are reported annually to the DWR, State Board, and TROA program. These estimates are developed on a calendar -year basis, not by WYs. The calendar -year extraction data is approximately equal to WY estimates due to the annual cycle of climatic conditions, including freezing temperatures and significant amounts of snow and other precipitation, which typically limits the need to pump groundwater in the spring and summer months of each WY. These estimated values are provided in Tables 1 and 2. A full reporting of annual 2021 estimates will be available later in 2022, in the TROA annual report. The locations of wells for the public and community water systems, and general locations of golf courses and non -community entities that also use groundwater in the MVGB, are shown on Figure 10. The distribution of groundwater extractions for the wells are illustrated by the size of the symbol (magnitude) and color (pumping entity). The largest volume of water extracted at any location in the MVGB is from the Martis Valley well, located near the airport, and has altered the regional groundwater flow direction. Three other wells north of the Truckee River and east of the town of Truckee are the next largest producers in the valley and changed the overall regional groundwater flow direction in both WYs. Groundwater pumping increased on average by about 800 AF during WY 2020 and 2021 contributing to the pumping depression. The depth of the pumping depression may also be greater due to drought conditions and lower overall regional groundwater levels. Figure 10 is also useful for comparison with the groundwater contours (presented in Section 2) and corresponds with the pumping data. Graphical representations of monthly and annual pumping for TDPUD and NCSD wells are presented on Figure 11. Seasonally, groundwater demand peaks in the summer and declines to approximately one-third to one -quarter of that amount during the winter and spring. This distribution suggests that calendar (for non -community users and golf course irrigation) and water year pumping estimates are typically similar in magnitude for this Basin, hence the tabulated totals in Tables 1 and 2 with calendar year pumping estimates are defensible surrogates to approximate water year pumping estimates. Figure 11 also shows that the overall pumping volume fluctuates from year to year but overall remains consistent unless dry conditions persist, varying by about 1,000 AF over the last 4 years. Groundwater use was higher in WY 2021 than in 2020, consistent with the second year of below -normal precipitation. Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 18 Table 1 Groundwater Pumping for Water Year 2019 - 2020 (values in acre-feet) 2019 2020 Annual Metered Agency Estimated Oct Nov Dec Jan Feb Mar Apr May Jun Jul AugSeR Total Percent Public Utility Water Purveyors 1 Truckee -Donner PUD Potable Water Year 1. Airport Well Metered 9 10 11 2. Martis Valley Well Metered 156 161 169 3. South Side Well Metered 0 0 0 4. Glenshire Dr Well Metered 9 0 0 S. Hirschdale Well Metered 1 1 1 6. Prosser Annex Well Metered 16 0 0 7. Prosser Heights Well Metered 7 0 0 8. Sanders Well Metered 0 0 0 9. Prosser Village Well Metered 50 40 43 10. Northside Well Metered 0 0 0 11. Old Greenwood Well Metered 23 12 24 12. Well 20 Metered 5 0 0 13. "A" Well Metered 0 0 0 Non Potable 14. Fibreboard Well Metered 30 3 0 15. Donner Creek Well Metered 0 0 0 16. Southside Well #1 Metered 1 1 0 Subtotal 308 228 247 Commu ' Northstar C.S.D. TH-1 Metered 2 1 3 TH-2 Metered 2 0 1 Well Metered 13 0 0 Well Metered 18 8 11 Well Metered 3 1 1 Subtotal 38 11 16 lNon-Community Water Purveyors3'1 N (Estimated using 2020 calendar year values.) Hobart Work Centers Estimated Aggregates Martis Valleys Estimated 14 12 13 12 20 10 21 20 7 159 158 158 165 168 182 208 219 220 212 2,175 0 0 0 0 0 0 0 0 0 0 0 0 0 0 8 43 77 69 51 257 1 1 1 1 1 1 1 1 1 9 0 0 0 0 17 23 26 26 24 132 0 0 0 0 9 14 16 16 15 78 0 0 0 0 31 39 39 38 36 183 45 33 27 32 82 97 104 103 92 747 0 0 0 0 0 14 18 20 16 68 24 20 26 30 48 65 91 83 66 512 0 0 0 0 8 15 19 18 16 81 0 0 0 0 0 0 0 0 0 0 0 0 0 15 68 85 102 98 74 474 0 0 0 5 22 40 50 53 34 203 0 0 0 0 0 2 0 1 1 5 242 224 232 261 493 655 782 767 645 5.083 71% Water Year 0 0 1 0 0 16 28 19 18 89 3 1 0 0 6 12 25 31 22 104 0 0 0 0 13 41 38 39 33 178 9 8 7 9 32 23 38 42 40 244 1 1 1 1 3 4 3 0 1 22 13 10 10 11 53 95 133 133 115 638 9% Calendar Year 0 120 120 2% Subtotal [Golf Courses"'Z� (Estimated using 2020calendar year volue Gray'sCrossing° Estimated (Served by TDPUD and included in the irreported pumping) Old Greenwood Estimated (Served by TDPUD and included in their reported pumping) Ponderosa (9-hole Course) Estimated (Private wells not operated by TDPUD, monthly pumping not available) Coyote Moon Estimated (Served by TDPUD and included in their reported pumping) Schaffer's Mills Estimated Lahontans Estimated Northsta rs Estimated Martis Camps Estimated Tahoe Donner Estimated (component of demand provided by TDPUD from wells in basin) 'Values reported in gallons and converted to acre-feet Values reported in million gallons and converted to acre-feet 3Estimated and obtained from Annual Inventoryof Water Use Lake Tahoe &Truckee River Basins Calendar Year 2020 °Groundwater use already accounted forin TDPUD reported pumping and not included in golfcourse demand subtotal sGroundwater use not currently available, used 2020 values as surrogate. Calendar Year 179 295 4 295 232 311 195 330 242 Total 7,155 Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 19 Table 2 Groundwater Pumping for Water Year 2020 - 2021 (values in acre-feet) 2020 2021 Annual Metered Agency Estimated Oct Nov Dec Jan Feb Mar Apr May Jun Jul AugSep Total Percent Public Utility Water Purveyors 1 Truckee -Donner PUD Potable Water Year 1. Airport Well Metered 0 0 0 0 0 7 38 46 47 52 67 49 306 2. Martis Valley Well Metered 199 120 123 135 98 92 110 132 197 157 139 132 1,635 3. South Side Well Metered 0 0 0 0 0 0 0 0 0 0 0 0 0 4. Glenshire Dr Well Metered 24 18 32 25 53 44 78 134 99 106 33 0 647 S. Hirschdale Well Metered 1 1 1 1 1 1 1 1 1 1 1 1 10 6. Prosser Annex Well Metered 18 0 0 0 0 0 17 27 29 27 23 12 153 7. Prosser Heights Well Metered 13 0 0 0 0 7 17 16 17 16 17 9 111 8. Sanders Well Metered 32 0 0 0 0 11 34 33 34 30 26 0 200 9. Prosser Village Well Metered 68 64 40 54 44 39 50 80 102 67 76 41 728 10. Northside Well Metered 0 0 0 0 0 0 0 14 20 20 13 0 68 11. Old Greenwood Well Metered 42 42 53 34 59 54 66 86 99 99 85 37 756 12. Well 20 Metered 11 0 0 0 0 3 13 18 20 19 14 6 104 13. "A" Well Metered 0 0 0 0 0 0 0 0 0 0 0 0 0 Non Potable 14. Fibreboard Well Metered 33 0 0 0 0 45 78 106 117 89 78 23 568 15. Donner Creek Well Metered 16 0 0 0 0 6 39 49 55 44 30 10 248 16. Southside Well #1 Metered 1 1 0 0 0 0 0 1 1 1 0 0 5 Subtotal 458 246 249 249 255 309 542 742 839 726 604 320 5,539 72% Commu 1111K.- Northstar C.S.D. Water Year TH-1 Metered 8 0 0 0 0 2 1 15 5 2 20 17 72 TH-2 Metered 22 5 1 7 0 0 0 9 41 51 25 20 180 Well Metered 13 0 0 0 0 0 0 13 41 38 39 33 178 Well Metered 18 8 11 9 8 7 9 32 23 38 42 40 244 Well Metered 3 1 1 1 1 1 1 3 4 3 0 1 22 Subtotal 64 15 13 17 9 10 12 72 114 133 127 112 696 9% lNon-Community Water Purveyors3'2 N (Estimated using 2021 calendar year values.) _ Calendar Year Hobart Work Centers Estimated 0 Aggregates Martis Valleys Estimated 120 Subtotal 120 2% Golf Courses3'Z (Estimated using 2021 calendar year value Calendar Year Gray'sCrossing° Estimated (Served by TDPUD and included in their reported pumping) 179 Old Greenwood Estimated (Served by TDPUD and included in their reported pumping) 295 Ponderosa (9-hole Course) Estimated (Private wells not operated by TDPUD, monthly pumping not available) 4 Coyote Moon Estimated (Served by TDPUD and included in their reported pumping) 295 Schaffer's Mills Estimated 232 Lahontans Estimated 311 Northsta rs Estimated 195 Martis Camps Estimated 330 Tahoe Donner Estimated (component of demand provided by TDPUD from wells in basin) 242 Total 7,669 'Values reported in gallons and converted to acre-feet Values reported in million gallons and converted to acre-feet 3Estimated and obtained from Annual Inventoryof Water Use Lake Tahoe &Truckee River Basins Calendar Year 2020 °Groundwater use already accounted forin TDPUD reported pumping and not included in golfcourse demand subtotal sGroundwater use not currently available, used 2020 values as surrogate. Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 20 Figure 10. Martis Valley Groundwater Basin Locations of Groundwater Extractions y ° re err 'rc •! k Boca ProssLr NEVADA M .Y�r �rarr� I Hirschdala s h- Prosser I r c Village ✓ui r t f Prosser Annex Well I — Tahoe Donner �7 he,Golf Club at I , r Prosser G ray's Crossing Old Greenwood Heights 41— E Old Greenwood I I TDPUD Municipal T kee L_._ __1 I Well — —" " Fibreboard T - j Golf Club Sanders Well Glenshire • t Coyote Moonlq� et Drive Aggregates Northstar (NCSD) 11 Truckee ttiv Martin j Northside Iro `� ee Martin ,Valley STZ) Municipal Well _f Valley Well l Goff Course oa Ponder— — I (General Well g 5outhside ; '�. YYY L� is c Dnnner Lake Donner Creek p -- ----- — --- --- f Location) `------�-� / Airport ----- ('re ake IVEVADACOUIVTY _—_— _ -- o -----' __ — — — —--- --.o' -----PLACER COUNTY Non -Community I (General Well -----`-- Location) Wt'ast ;fax 1 V Situ Q d, . * r Schaffer's Mill THi � Scale of Extraction Magnitude } Well 31* CNell1 N�orthstar's T Wells Extracting Well2 If Course Y d� Club I >2000 AF per Water Mortis Year Camp Lahontan Club Golf Club Big Spring s o 9 `�. I Wells Extracting u rt >400 AF per Water Year I r� c Wells Extracting o C <400 AF per Water cree I Year 0 Resort F = Creeks and Rivers d 'r I e i Mantis Valley `creE,k a Groundwater Basin ni I Deep Creek County Boundary 9 o N Martin Valley Annual Report MARTIS VALLEY GROUNDWATER BASIN 2 1 0 2 Water Year 2020 and 2021 W F Nevada and Placer Counties, California E LOCATIONS OF GROUNDWATER EXTRACTIONS MilesTruckee-Qonner Public Utility Qistrict I Consultants APRIL 2022 FIGURE 10 Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 21 [This page intentionally left blank.] Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 22 Figure 11. Martis Valley Groundwater Basin Community Water System Monthly Pumping Totals 900 --*-- TDPUD Groundwater Production t NorthstarC.S.D. Groundwater Production ' .. •� TDPUD Water Year Totals WY 2020 800 1 • • •� NorthStar C.S.D. Water Year Tctals WY 2018 5083 AF WY 2016 WY 2017 4824 AF 4668 AF 4519 AF / " • " �' WY 2019 700 4••+••• 4411AF '••••••s 4 0 0 * & 0 c 0 > 500 200 WY 2016 100 522 AF WY 2017 WY 2018 579 AF 455 AF ��' a•••s ••••s;01 WY 2019 WY 2020 497 AF 638 AF WY 2021 5453 AF ,•r••aA*' WY 2021 741 AF y� yh y<1 lb y<1 y( y�b y(o �0 y'1 y11 yA �'1y°) y°' yA ya5 .y0 �O ,LO ti0 by L'y Ly .yry IL Note: Monthly pumping totals shown at end of each month. Month - Year 6000 4000 Total Water Year Pumping 3000 by Entity (Acre Feet per Water Year) 2000 1000 Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 23 [This page intentionally left blank.] Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 24 4. Surface Water Diversions Although the Truckee River and multiple tributaries course throughout the MVGB, surface water constitutes less than one percent of Basin water supply. The total surface water diverted for use is about 450 AF in 2020 and 2021, but not all was diverted within the MVGB. Estimated surface water diversions are listed in Tables 3 and 4 for WYs 2020 and 2021, respectively. Water diversions for 2021 will be updated when the 2021 TROA annual report is released in 2022. NCSD has water rights to use water from Big Springs, which is located outside the Basin but within the watershed as shown on Figure 11. Northstar Resort uses water from the spring, primarily for snowmaking. A portion of this water supplies recharge to the Basin aquifer by storing water as snow, which later melts, becomes runoff, and infiltrates into the Basin. Water from the spring is also used in the Basin, at the Northstar golf course, along with other commercial and domestic uses. The amount of groundwater recharge attributable to surface water from Big Springs cannot be quantified at this time. A second surface water source, from within the MVGB, is used for irrigation at the Ponderosa Golf Course, but its diversion point is unidentified. Some deep percolation from turf irrigation also provides groundwater recharge within the MVGB. Table 3 Surface Water Usage Reported for Water Year 2019-2020 (values in acre-feet) 2019 1 2020 1 Annual Metered Agency Estimated Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Total Public Utility Water Purveyors Truckee -Donner PUD 1 Metered 0 0 0 0 0 0 0 0 0 0 0 0 0 Subtotal 0 ,Community Water Purveyors �0 calendar year values Northstar C.S.D.' Metered 11 0 24 13 0 0 0 0 0 0 0 1 50 Non-PUD Community Purveyors Estimated 283 Subtotal 333 bon -Community Water Purveyors 2020 calendar year values) Hobart Work Center Estimated 0 Aggregates Martis Valley Estimated 53 Subtotal 53 olf Cours (2020 calendar year values from Annual Water Use report 2020) Ponderosa Golf Course Metered 73 Northstar Golf Course (from Big Springs)' Estimated 0 Subtotal 73 Total 4S9 n/a = Not Applicable 1 TDPUD has an allocation of Truckee River flows but does not use it, has no infrastructure to access it, and has no plans to use it. 2 NCSD holds ripariain water rights for use of Big Springs, which is outside of the MVGB. A portion of this water is used for limited municipal use within the MVGB and Northstar Golf Course. Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 25 Table 4 Surface Water Usage Reported for Water Year 2020-2021 (values in acre-feet) 2020 2021 Annual Metered Agency Estimated Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Total ,Public Utility Water Purveyors Truckee -Donner PUD t Metered 0 0 0 0 0 0 0 0 0 0 0 0 0 Subtotal 0 Community Wate, (2021 calendar ye Northstar C.S.D.2,3 (M&I) Metered 4 14 9 9 0 0 0 0 0 0 0 0 36 Non-PUD Community Purveyors Estimated (From Non-PUD Community Purveyors) 283 Subtotal 319 [on -Community Water Purveyo Hobart Work Center Estimated 0 Aggregates Martis Valley3 Estimated 53 Subtotal 53 Golf Course (2021 calendar year values Estimated from Annual Water Use report 2020) Ponderosa Golf Course3 Estimated 73 Northstar Golf Course (from Big Springs) 2,3 Estimated 0 Subtotal 73 Total 445 n/a = Not Applicable 'TDPUD has an allocation of Truckee River flows but does not use it, has no infrastructure to access it, and has no plans to use it. z NCSD holds ripariain water rights for use of Big Springs, which is outside of the MVGB. A portion of this water is used for limited municipal use within the MVGB and Northstar Golf Course. 3 2021 values not reported at this time. Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 26 5. Groundwater Recharge Wastewater is exported from the North Lake Tahoe area and is sent to the T-TSA water treatment plant, located in the MVGB. Total estimated monthly wastewater imports to the MVGB from areas outside the Basin for the past 2 water years, as well as metered wastewater (weir) derived from within the MVGB, from the Truckee Sanitary District (TSD), were provided by T-TSA and are listed in Tables 5 and 6 for WYs 2020 and 2021, respectively. About 1,800 AF and 1,700 AF of wastewater was imported into the MVGB in WYs 2020 and 2021, respectively. The treated water from the T-TSA is recharged into the MVGB groundwater system through subsurface leach fields (pipes with holes surrounded by gravel) under permit with the Lahontan Regional Water Quality Control Board. The locations of the leach fields are shown on Figure 1. About 3,750 AF of treated water was recharged into the MVGB in both WYs 2020 and 2021. Wastewater from TSD is partially derived from groundwater pumping within the MVGB and partially offset impacts of local pumping near the Truckee River. Table 5 Estimated Groundwater Recharge from T-TSA for Water Year 2019 - 2020 acre-feet 2019 2020 Annual Tahoe -Truckee Sanitary Agency Metered (T-TSA) Sources of Inflows 1 Estimated Oct Nov Dec Jan Feb Mar Air May Jun Jul Aug Sep WY Total Lake Tahoe Area (Imported water) Estimated 86 80 162 156 148 145 155 148 159 200 182 152 1,773 Truckee Sanitary District (TSD) Metered 193 179 208 176 142 113 136 153 170 198 161 142 1,970 Total 3,743 1 Deliveries to treatment facility from outside the MVGB provided by T-TSA and are converted from million gallons to acre-feet 2 Metered readings from Granite Flats used to calculate imported wastewater from Lake Tahoe area Table 6 Estimated Groundwater Recharge from T-TSA for Water Year 2020 - 2021 (acre-feet) 2020 2021 1 Annual Tahoe -Truckee Sanitary Agency Actual (T-TSA) Sources of Inflows 1 Estimated Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep WY Total Lake Tahoe Area (Imported water) Estimated 143 137 138 140 149 159 144 129 146 178 126 88 1,677 Truckee Sanitary District (TSD) Metered 125 123 159 200 181 197 186 178 198 232 172 143 2,093 Total 3,770 1 Deliveries to treatment facility from outside the MVGB provided by T-TSA and are converted from million gallons to acre-feet 2 Metered readings from Granite Flats used to calculate imported wastewater from Lake Tahoe area Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 27 6. Total Water Use The total estimated groundwater and surface water use in the MVGB by sector is summarized in Table 7. Over 90 percent of the water use was provided from groundwater, with a total water use of 7,155 AF and 7,669 AF in 2020 and 2021, respectively. About one-half of the groundwater pumped was returned to the Basin after being treated by T-TSA. Table 7 Total Water Use for Water Years 2020 & 2021 (acre - Water Use Sector 2020 2021 Municipal and Industrial (M&I) 6,227 6,727 Groundwater Metered 5,721 6,235 Groundwater Estimated 120 120 Surface Water Metered 50 36 Surface Water Estimated 336 336 Golf Courses 1,387 1,387 Groundwater Estimated 1,314 1,314 Surface Water Estimated 73 73 Subtotal Groundwater 7,155 7,669 Subtotal Surface Water 459 445 Total Water Use 7,614 8,114 T-TSA Groundwater Recharge 3,743 3,770 Total 3,871 4,344 Note: Only includes water sources in MVGB, see Tables 3 and 4 and does not include evapotranspiration from native vegetation. Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 28 7. Change in Groundwater Storage An empirical approach was used to calculate change in storage using spring groundwater elevation contours for 2016 through 2021. The spring contour surfaces were then subtracted to produce water level change distributions for the last two WYs. The use of spring -to -spring water level differences was deemed to be the most appropriate when assessing ambient groundwater conditions, because it has less influence of temporal, localized changes due to pumping adjacent to monitoring wells. Figures 12 and 13 spatially show the estimated groundwater elevation changes (current year elevations subtracted from previous year elevations). Portions of the Basin (northwest, southwest, and southeast corners) with no groundwater level monitoring wells were not contoured. According to DWR files (DWR, 2022) there are no irrigation, municipal or domestic wells in the northwest and southwest corners of the Basin. In the southwest corner there are four domestic wells but their logs show that they encountered lava flows and ash layers, and no sediments so it is unknown whether these wells would provide representative groundwater levels with the rest of the Basin. Change in storage estimates are dependent upon the assumed specific yield (the percent of sediments with pore space that contains water that can be drained by gravity) or storage coefficient (similar to specific yield but used when aquifers are more confined as is typical with depth) of the aquifer formation. Given the complex and often interbedded nature of the MVGB aquifer system, an average of depth storage coefficients (ranging from 0.1— 0.05) were used for the analysis. The results and input values are presented in Table 8. Groundwater in storage in the MVGB decreased in both WY 2020 and 2021. Most of the change in storage is likely due to the reduced groundwater recharge due to the drought conditions with the greatest differences being located near the highest density of pumping. The lack of recharge is evidenced by the groundwater extractions being within 2,000 AF of the change in storage estimates. Table 8 Estimated Change in Storage Basin Area Used Average Estimated Time Periods for 1 Groundwater Average Storage Change in Groundwater Level in Analysis Level Change Coefficients Storage Elevation Comparisons (acres) (feet) (AF) Spring 2019 - Spring 2020 24,500 -5.45 0.075 -10,007 Spring 2020 - Spring 2021 24,500 -3.72 0.075 -6,841 Total Change 2020 and 2021 WYs -16,848 i Basin Area limited to extent of MVGB with groundwater elevation data to limit interpolation error Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 29 Figure 12. Martis Valley Groundwater Basin Change in Groundwater Elevation, Spring 2019-Spring 2020 n a r ,fir � � v ------------------------ -I Miles 0"o' 17 Donner Lake s'- n � 1ON16E22H 6.i� �` �18N17E3 L001M TH-Prosser. - -2 3 V.i�llage � -2.3 17N17EQ6 e' 01 M -8.8 n NTH -Fibreboard 01 -7.4 �/17NWEWP001M VALLEY r / VALLEY Martis Valley 6.6 BASIN 9 -0.9 'k17N17E18C001,M 31 K003M -$'8 -7,g f_— —� , cy u.s - _—_NEVAQACOUN�Y _—_--- --- — --- - PLACER COUNTY 17N17E19K001.M 17N1-7-E29.B0`1M H1 -0.9 Well 1Well 3 TH 2 Well 2 'lr � Martis Valley Annual Report Water Year 2020 and 2021 Nevada and Placer Counties, California Truckee Donner Public Utility District L_J r _ TDPUD Municipal Well 4. � Northstar (NCSD) Municipal Well Monitoring Well r Golf Course ✓�Cl. Change in y Groundwater ' — — Elevation (feet) Spring 2019 - _ Spring 2020 -2 -4 l -6 n -80 -12 -14 -16 -18 Martis Valley Groundwater Basin r I County Boundary MARTIS VALLEY GROUNDWATER BASIN CHANGE IN GROUNDWATER ELEVATION SPRING 2019 TO SPRING 2020 F G L I Consultants APRIL2022 u FIGURE 12 Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 30 Figure 13. Martis Valley Groundwater Basin Change in Groundwater Elevation, Spring 2020-Spring 2021 -- Dorrrrer ],uke — s ` a .4 Roca �18N16E22H0701-M -2.1 ro enoir 18 TH-, r sser��' 4 8171 1VMl�age �--- i� l3(_117N117EW 01M TDPUD Municipal Well Northstar (NCSD) Municipal Well ,.� Monitoring Well �« o Golf Course Change in 17N16E11F001tM NTH-F 6'reboard� .6 -17.4 , j 2 17N17E07POO1M VA L EIY TH-Martis Valley 1.3 BASIN 1.6 17N17E18C001M r.. 17N 6E13K003M -5.4 orris �2COU -- N EVA— NL - - ---------------- ----- ---- PLACER COUNTY 17N17E19K001;M 17N17E29B001M. �'-2. T t -3 well 1�Well 3 TH z r f Well.2 Groundwater Elevation (feet) Spring 2020 - 1M Spring 2021 "� } $ 6 4 2 t E 0 I ` y _ All" - I -2 A i jl -4 ----------------------------i 6 I -10 I Z -12 -14 — -16 -18 -20 -22 \ L -24 — — Martis Valley Groundwater Basin County Boundary " Martis Valley Annual Report MARTIS VALLEY GROUNDWATER BASIN 2 1 0 2 Water Year 2020 and 2021 CHANGE IN GROUNDWATER ELEVATION W E Nevada and Placer Counties, California SPRING 2020 TO SPRING 2021 Miles GE1s Truckee Donner Public Utility District Consultants APRIL 2022 FIGURE 13 Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 31 Historic trends in the estimated annual and cumulative change of groundwater in storage, along with water year type and annual groundwater use, are shown on Figure 14. Storage change and groundwater use estimates prior to WY 2017 were derived from previous analyses. Over the last 2 WYs, groundwater in storage decreased by about 17,000 AF as a result of 2 years of dry conditions resulting in less recharge and with increased pumping. For perspective, the Basin has approximately 484,000 AF in storage, so the overall change is relatively small (about 3.5% over the 2-year period) in comparison to the total water stored in the Basin. Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 32 Figure 14. Change in Storage and Groundwater Use 600,000 500,000 400,000 aj V a7 CM 300,000 r� t U a1 bA [0 O 200,000 a� 3 s= 0 0 C7 100,000 Estimated Cumulative Storage Charge tEstimate d Annual Storage Change Wet Above Normal Below Normal Dry (Estimated Groundwater Use Change -in -Storage pre-2016 from Water Budget Calculations 0 ■ -100 000 Change -in Storage 2016to 2021 calculatedfrom groundwater contour map differences 14,000 12,000 n 10,00o m G) m x m 6,000 0 0 V7 4,000 r; 2,000 0 N ro �t Ln CO t• 00 an O r-I N rn �t Ln CO r� 00 67 O r-I N O O O O O O O O r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I N N N O O O O O O O O O O O O O O O O O O O O O N N N N N N N N N N N N N N N N N N N N N Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 33 [This page intentionally left blank.] Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 34 8. Groundwater Management Activities The MVGB Agencies continue to invest in the stewardship of the Basin and practicing of adaptive management to proactively ensure that the Basin operates within its sustainable yield. This includes frequent monitoring of key data points and interactions with local stakeholders' meetings. The most significant management action has been the voluntary implementation of monthly monitoring of groundwater levels for all wells in the CASGEM program. This proactive move to monthly monitoring over 5 years ago and well before the mandate was, in part, to investigate and address uncertainties in seasonal variations. Without this proactive change the lower groundwater levels during the summer months noted in WY 2020 and 2021 would not have been detected. The results and trends from this improved monitoring program are presented in this report, and both TDPUD and NCSD, who are responsible for the monitoring, intend to continue this monthly monitoring going forward as an MVGB adaptive management strategy. The MVGB Agencies continue to interact with local environmental interests and MVGB stakeholders to provide information and hear concerns. Primarily, this has been done by the participation in the Truckee River Basin Working Group (TRBWG). The TRBWG was formed with the passage of the TROA 20 years ago and has been strengthened with the support of the newly formed DWR-TROA division. The TRBWG is comprised of the California stakeholders in the river watershed including water purveyors, local governments, environmental interests, recreational interests, DWR, California Department of Fish and Wildlife, United States Forest Service, and others. The MVGB Agencies shared the findings from the 2018 and 2019 Annual Report with stakeholders and are planning to share this report and discuss the findings in the near future. Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 35 9. Conclusions Groundwater levels decreased in the MVGB through WYs 2020 and 2021 in response to drought conditions and increased pumping. Groundwater levels in most monitoring wells have remained above their respective historic low levels when compared to historic spring and fall levels. Because of more frequent monthly monitoring, three wells reported groundwater levels that were lower than previously measured levels. The monthly monitoring also showed groundwater levels quickly recovered, indicating the lower groundwater levels were a localized effect due to pumping. Groundwater pumping increased by about 10 percent, averaging about 800 AF, during these two water years. Most of the increase was north of the Truckee River. In response to the increased groundwater use in this area a pumping depression formed that extended beneath the river. Because of the drought conditions the pumping depression did not refill during the winter months. The pumping depression may have increased surface water depletion from the Truckee River but any depletion was offset by recharge from the T-TSA facility, which contributed to approximately 50 percent of all of the groundwater pumped in the Basin. Historic low precipitation and higher groundwater use in WY 2020 and 2021 resulted in an overall decrease in groundwater storage, similar to other northern California groundwater basins. During the 2- year period, groundwater in storage decreased by about 17,000 AF, or about 3.5 percent of the total storage in the Basin. Although the Basin had a decrease in groundwater storage this is considered to be part of a natural cycle, and as long as groundwater levels recover in future years, the Basin would still be considered sustainable. Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 36 10. References Brown and Caldwell, 2013. Martis Valley Groundwater Management Plan (GMP). California Department of Water Resources (DWR), 2016. California's Groundwater. Bulletin 118- Interim Update 2016. California Department of Water Resources (DWR), 2021. Annual Inventory of Water Use, Lake Tahoe and Truckee River Basins, Calendar Year 2020. California Department of Water Resources (DWR), September 2021. Water Year 2021: An Extreme Year. California Department of Water Resources (DWR), accessed May 2022. California Groundwater Live. htlps://sgma.water.ca.gov/CaIGWLive/#wells GEI, March 2018. Annual Report for the Martis Valley Groundwater Basin, Sustainable Groundwater Management Act Alternative Submittal, Water Years 2016 and 2017. GEI, January 2021. Annual Report for the Martis Valley Groundwater Basin, Water Years 2018 and 2019. Truckee Donner Public Utility District (TDPUD), December 2016. Martis Valley Groundwater Basin Sustainable Groundwater Management Act Alternative Submittal. Martis Valley Groundwater Basin Annual Report GEI Consultants, Inc. Water Years 2020 and 2021 37 Attachment A. Monitoring Well Hydrographs Water Years 2020 and 2021 GEI Consultants, Inc. Annual Report for Martis Valley Groundwater Basin Alternative Submittal 5,950 5,900 5,850 5,800 c 0 a, w 5,750 v U 7 N - 5,700 5,650 5,600 5,550 17N16E11F001M 0) o rI N m a Ln �o rl 00 0) O rI N m a Ln �o rl 00 m o rI N m v m a rl 00 rn O c-I 00 Ql Ql 0) Ql 0) Ql Ql 0) Ql 0) O O O O O O O O O O r-I r-I r-I r-I r-I r-I r-I r-I 1-I 1-I N N O m m O m O m m 0) Ql 0) O O O O O O O O O O O O O O O O O O O O O O rl i--I i--I r-I i--I r-I 1-I 1-I r-I 1-I r-I N N N N N N N N N N N N N N N N N N N N N N O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O ci ci ci ci ci ci ci ci ci ci ci ci ci ci ci -4 -4 ci ci ci ci ci ci ci ci ci ci ci ci ci ci ci ci Water Year 5,950 5,900 5,850 E cp 5,800 +f c 0 w 5,750 v U i 7 N au 5,700 5,650 5,600 5,550 17N16E13K001M 0) o N c1i rm a Ln �o rl 00 0) O N c1i rm a Ln �o rl 00 m O N c1i rm v in �o rl 00 rn O N 00 Q1 Q1 0) Q1 0) Q1 91 O 91 O O O O O O O O O O O c-i 1-1 c-i 1-1 1-1 c-i 1-1 c-i 1-1 1-1 N N O Ql Ql O Ql O Ql Ql 0) Ql 0) O O O O O O O O O O O O O O O O O O O O O O r-I i--i i--i c-I i--i c-I 1-1 1-1 c-I 1-1 r-i N N N N N N N N N N N N N N N N N N N N N N O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O Water Year 17N16E13K003M 5,950 5,900 5,850 E rp 5,800 +f c 0 w 5,750 v U i 7 N au 5,700 5,650 5,600 —— WSE Historical Low Level 5,550 0) o rI N m a Ln �D r` 00 0) O rI N m a Ln �D r` 00 m o rI N m v m w r` 00 rn O c4 00 Q1 Q1 0) Q1 0) Q1 Q1 0) Q1 0) O O O O O O O O O O c 1 r-I c 1 r 1 r 1 r-I r-I r-I 1-I 1-I N N O m m O m O m m 0) Ql 0) O O O O O O O O O O O O O O O O O O O O O O N N N N N N N N N N N N N N N N N N N N N N O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O ci ci ci ci ci ci ci ci ci ci ci ci ci ci ci -4 -4 ci ci ci ci ci ci ci ci ci 1-I ci ci ci ci ci ci Water Year 5,950 5,900 5,850 E rp 5,800 +f c 0 w 5,750 v U i 7 N au 5,700 5,650 5,600 5,550 17N16E17F002M GS Elevation WSE Historical Low Level m o N c1i ro a Ln �D r` 00 m O N cIj ro a Ln �D r` 00 m O N cIj ro v in �D r` 00 rn O N 00 Cn of of of of of of of of of O O O O O O O O O O c-i 1-1 c-i 1-1 1-1 c-i 1-1 c-i 1-1 1-1 N N of of of of of of of of of of of O O O O O O O O O O O O O O O O O O O O O O ­1 i-q i-q r-i i-q r-i 1-1 1-1 c-I 1-1 r-i N N N N N N N N N N N N N N N N N N N N N N O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O Water Year 5,950 5,900 5,850 E rp 5,800 +f c 0 w 5,750 v U Ln au 5,700 5,650 5,600 5,550 17N17E05D001M GS Elevation WSE Historical Low Level 0) O 1-I N m IzT Ln LD I, 00 0) O -4 N m IZT Ln LD I" 00 m O -1 N m �t m LD I, 00 m O -4 00 m m 0) m 0) m m O m O O O O O O O O O O O r-I r-I r-I r 1 r 1 r-I r-I r-I 1-I 1-I N N O m m O m O m m 0) m 0) O O O O O O O O O O O O O O O O O O O O O O N N N N N N N N N N N N N N N N N N N N N N O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O ci ci ci ci ci ci ci ci ci ci ci ci ci ci ci -4 -4 ci ci ci ci ci ci ci ci ci ci ci ci ci ci ci ci Water Year 5,950 5,900 5,850 E cp 5,800 +f c 0 w 5,750 v U 7 N au 5,700 5,650 5,600 5,550 17N17E07P001M 0) o rI N m a Ln �o rl 00 0) O rI N m a Ln �o rl 00 m o rI N m v m a rl 00 rn O c-I 00 Ql Ql 0) Ql 0) Ql Ql 0) Ql 0) O O O O O O O O O O r-I r-I r-I r-I r-I r-I r-I r-I 1-I 1-I N N O m m O m O m m 0) Ql 0) O O O O O O O O O O O O O O O O O O O O O O rl i--I i--I r-I i--I r-I 1-I 1-I r-I 1-I r-I N N N N N N N N N N N N N N N N N N N N N N O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O ci ci ci ci ci ci ci ci ci ci ci ci ci ci ci -4 -4 ci ci ci ci ci ci ci ci ci ci ci ci ci ci ci ci Water Year 5,950 5,900 5,850 V) E rp 5,800 +f c 0 w 5,750 v U i 7 N au 5,700 5,650 5,600 5,550 17N17E18C001M GS Elevation WSE Historical Low Level m o N rIj rm a Ln �D r` 00 m O N rIj rm a Ln �D r` 00 m O N rIj rm v Ln �D r` 00 rn O N 00 Cn Cn O 91 O 91 91 O 91 O O O O O O O O O O O c-i c-I c-i c-I c-I I-q c-I c-i c-I c-I N N O Ql Ql O Ql O Ql Ql O Ql O O O O O O O O O O O O O O O O O O O O O O O r-I i-q i-q r-i i-q r-i 1-1 1-1 c-I 1-1 r-i N N N N N N N N N N N N N N N N N N N N N N O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O Water Year 5,950 5,900 5,850 E cp 5,800 +f c 0 w 5,750 v U 7 N au 5,700 5,650 5,600 5,550 17N17E19K001M 0) o rI N m a Ln �o rl 00 0) O rI N m a Ln �o rl 00 m o rI N m v m a rl 00 rn O c-I 00 Ql Ql 0) Ql 0) Ql Ql 0) Ql 0) O O O O O O O O O O r-I r-I r-I r-I r-I r-I r-I r-I 1-I 1-I N N O m m O m O m m 0) Ql 0) O O O O O O O O O O O O O O O O O O O O O O rl i--I i--I r-I i--I r-I 1-I 1-I r-I 1-I r-I N N N N N N N N N N N N N N N N N N N N N N O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O ci ci ci ci ci ci ci ci ci ci ci ci ci ci ci -4 -4 ci ci ci ci ci ci ci ci ci ci ci ci ci ci ci ci Water Year 5,950 5,900 5,850 E cp 5,800 +f c 0 w 5,750 v U 7 N au 5,700 5,650 5,600 5,550 17N17E29B001M 0) o rI N m a Ln �o rl 00 0) O rI N m a Ln �o rl 00 m o rI N m v m a rl 00 rn O c-I 00 Ql Ql 0) Ql 0) Ql Ql 0) Ql 0) O O O O O O O O O O r-I r-I r-I r-I r-I r-I r-I r-I 1-I 1-I N N O m m O m O m m 0) Ql 0) O O O O O O O O O O O O O O O O O O O O O O rl i--I i--I r-I i--I r-I 1-I 1-I r-I 1-I r-I N N N N N N N N N N N N N N N N N N N N N N O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O ci ci ci ci ci ci ci ci ci ci ci ci ci ci ci -4 -4 ci ci ci ci ci ci ci ci ci ci ci ci ci ci ci ci Water Year 5,950 5,900 5,850 E rp 5,800 +f c 0 w 5,750 v U i 7 N au 5,700 5,650 5,600 5,550 18N16E22H001M - GS Elevation WSE Historical Low Level 0) O 1-I N m IzT Ln LD I, 00 0) O -4 N m IZT Ln LD I" 00 m O -1 N m �t m LD I, 00 m O -4 00 m m 0) m 0) m m O m O O O O O O O O O O O r-I r-I r-I r-I r-I r-I r-I r-I 1-I 1-I N N O m m O m O m m 0) m 0) O O O O O O O O O O O O O O O O O O O O O O r-I i--I i--I r-I i--I r-I 1-I 1-I r-I 1-I r-I N N N N N N N N N N N N N N N N N N N N N N O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O ci ci ci ci ci ci ci ci ci ci ci ci ci ci ci -4 -4 ci ci ci ci ci ci ci ci ci ci ci ci ci ci ci ci Water Year 5,950 5,900 5,850 E rp 5,800 +f c 0 w 5,750 v U i 7 N au 5,700 5,650 5,600 5,550 18N17E33L001M GS Elevation WSE — I I I I Historical Low Level m o N r1i rm a Ln �D r` 00 m O N rIj rm a Ln �D r` 00 m O N rIj rm v in �D r` 00 rn O N 00 Q1 Q1 O Q1 O Q1 91 O 91 O O O O O O O O O O O c-i 1-1 c-i 1-1 1-1 c-i 1-1 c-i 1-1 1-1 N N O Ql Ql O Ql O Ql Ql O Ql O O O O O O O O O O O O O O O O O O O O O O O r-I i--i i--i c-I i--i c-I 1-1 1-1 c-I 1-1 r-i N N N N N N N N N N N N N N N N N N N N N N O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O Water Year Fibreboard (TH) 5,950 5,900 5,850 E ca 5,800 c 0 w 5,750 v U 7 N a; 5,700 5,650 GS Elevation 5,600 WSE Historical Low Level 5,550 10/2010 10/2011 10/2012 10/2013 10/2014 10/2015 10/2016 10/2017 10/2018 10/2019 10/2020 10/2021 Water Year Martis Valley (TH) 5,950 5,900 5,850 E ca 5,800 c 0 w 5,750 v U 7 N a; 5,700 5,650 5,600 5,550 10/2010 10/2011 10/2012 10/2013 10/2014 10/2015 10/2016 10/2017 10/2018 10/2019 10/2020 10/2021 Water Year Prosser Village (TH) 5,950 5,900 5,850 E ca 5,800 c 0 w 5,750 v U 7 N a; 5,700 5,650 5,600 5,550 10/2010 10/2011 10/2012 10/2013 10/2014 10/2015 10/2016 10/2017 10/2018 10/2019 10/2020 10/2021 Water Year