STATE OF CALIFORNIA CALIFORNIA NATURAL RESOURCES AGENCY DEPARTMENT OF WATER RESOURCES DIVISION OF SAFETY OF DAMS INSPECTION OF DAM AND RESERVOIR IN CERTIFIED STATUS Name of Dam Soulajule Darn No. 33-9 County Marin Type of Dam ERTH Type of Spillway Concrete weir and chute Water is 1 .3 feet above the spillway crest and 10.7 feet below the dam crest. Weather Conditions Overcast with light rain Contacts Made Lucy Croy, Trinity Leonard, and Carl Sanders during the inspection Reason for Inspection Periodic Evaluation Important Observations, Recommendations or Actions Taken Overall care and maintenance ofthe dam and appurtenances remains quite good, though consistent annual vegetation control is required to prevent emerging vegetation from reducing the effectiveness of inspection and monitoring for seepage and other defects. Primary access to the dam is limited when the spillway is flowing. All-weather access for any and all equipment required to safely operate the dam and reservoir is a dam safety requirement. Existing access should be improved, or alternative all?weather access should be provided if not already in place. Conclusions From the known information and visual inspection, the dam, reservoir, and the appurtenances are judged safe i for continued use. Observations and Comments Dam The visible portions of the upstream face, crest, face, and abutments are in satisfactory condition, with no indication of surficial distress or instability. The upstream riprap armor remains in satisfactory condition and continues to provide reasonably adequate protection against wave action. Overall care and maintenance of the dam and appurtenances remains quite good, though consistent annual vegetation control is required to prevent emerging vegetation from reducing the effectiveness of inspection and monitoring for seepage and other defects. Mr. Sanders said he will continue removing excess vegetation later in the season when access to the face of the embankment is improved. Rodent control remains is satisfactory and only minor indications of burrowing are evident along portions of the crest. Spillway The approach, control section, and exit channel were open and clear; a polyethylene log boom was in place several hundred feet upstream ofthe dam. The spillway was flowing approximately 1.3 feet deep across the entrance weir. Flow within the concrete spillway chute appeared normal, and pockets and holes near the base of the concrete apron were repaired last year. Large bushes along the lower left spillway wall have also been trimmed back as recommended. The current design storm, prepared in 1978, is fora 10,000 year return period producing 15,223 (~814 sq mi) from the 18. 7 square mile drainage area. The spillway capacity Is ~17, 300 which Is greater than the peak inflow. Total freeboard Is 12 feet and the residual freeboard for the design storm is 3. 3 feet. Freeboard Is satisfactory ix?: - i Inspected by Lowe Photos taken? Yes No Date of Inspection 7 February 2017 I cc for Owner/Book Date of Report 10 February 2017 Li il?} ?r f) ?ail] DWR 1261 (Rev. 10/09) Sheet I of INSPECTION OF DAM AND RESERVOIR IN CERHFIED STATUS Name of Dam Soulajule Dam No. 33-9 Date of inspection 7 February 2017 Observations and Comments Outlet Seegage Instr. Other Five 36?inch diameter butterfly valves mounted on the inclined inlet structure provides upstream control for the fully encased outlet. The five mechanically operated valves are located at elevations 323.0?, 305.5', 228.0?, 270.5?, and 253.0?. control is provided by a pair of butterfly valves arrayed in series; a 36?inch butterfly valve within a concrete vault, followed by a recently installed 48-inch butterfly valve buried between the vault and outlet energy dissipater discharge. The outlet is normally pressurized. None of the outlet controls were cycled during this inspection. All of the outlet controls were partially cycled during the 5 April 2016 inspection, and all outlet controls were fully cycled and found to be in satisfactory operating condition during the February 24, 2015 periodic inspection. Rainfaii prevented evaluation for minor seepage. No evidence of significant seepage was observed within the face, groins, or abutments. The seepage monitoring weir next to the right side of the outlet energy dissipating structure was inundated by flow over the spiilway, and could not be monitored during this inspection. Instrumentation consists of the following: a Twenty-one (21) survey monuments. Survey monuments were installed to measure post construction settlement and to monitor settlement and lateral displacement of the embankment crest and face following significant seismic events. Surveys are performed approximately every five years. a Nineteen (19) piezometers. Piezometers were installed to monitor post construction pore water pressure and to monitor the phreatic surface within the embankment. Piezometers are read a One (1) 90-degree V?notch weir. The weir was installed to measure seepage from the toe drain and is monitored The last instrumentation data was received from the owner on 16 December 2015, and no new data has been received since that time. The last instrumentation review is presented in the 5 April 2016 inspection report, and is not repeated here; I direct the reader to the earlier report for a detailed explanation of the instrumentation monitoring the dam, and the performance of the dam as reflected in the 16 December2015 submittal. The conclusion of the April 2016 review was that, ?Based on the data submitted the dam appears to be performing satisfactorily, and no additional instrumentation is believed necessary at this time". Primary access to the dam is limited when the spillway is fiowing. The alternative access road is only partially armored, and may not be suitable for all equipment or in all weather. All?weather access for any and all equipment required to safety operate the dam and reservoir is a dam safety requirement. Existing access should be improved, or alternative all?weather access should be provided if not already in place. DWR1261 (rev.10f09) Sheet 2 of 5 INSPECTION OF DAM AND RESERVOIR IN CERIIFIED STATUS Name of Dam Souiajule Dam No. 33?9 Date of Inspection 7 February 2017 The upstream face of the embankment as viewed from the spillway entrance. The face of the embankment as viewed from the alternative access road. DWR1261 (rev. 10109) Sheet 3 of 5 INSPECTION OF DAM AND RESERVOIR IN CER IFIED STATUS Name of Dam Souiajule Dam No. 33-9 Date of Inspection 7 February 2017 ..-- 9.3-: Ln A closer look at the right groin and abutment. Scotch broom and other woody growth throughout the embankment, and within 15? of the groins, should be removed. 1.3' flow over the spiliway entrance weir. Sheet 4 of 5 INSPECTION JF DAM AND RESERVOIR IN CER. STATUS Name of Dam Soulajule Darn No. 33-9 Date of Inspection 7 February 2017 The face as viewed from the alternative access road. The alternative access road is only partially armored, and may not be suitable for all equipment or in all weather. Spillway flow over the primary access road. All-weather access for any and all equipment required to safely operate the dam and reservoir is a dam safety requirement. Sheet 5 of 5 STATE OF CALIFORNIA CALIFORNIA NATURAL RESOURCES AGENCY DEPARTMENT OF WATER RESOURCES DIVISION OF SAFETY OF DAMS INSPECTION OF DAM AND RESERVOIR IN CERTIFIED STATUS Name of Dam Soulajule Dam No. 33?9 County Marin Type of Dam ERTH Type of Spillway Concrete weir and chute Water is 0.5 feet below the spillway crest and 12.5 feet below the dam crest. Weather Conditions Clear and mild Contacts Made Alex Anaya and Carl Sanders during the inspection Reason for Inspection Periodic Evaluation Important Observations, Recommendations or Actions Taken Overall care and maintenance of the dam and appurtenances has improved significantly over the past three years. Mr. Anaya has addressed all safety and maintenance concerns expeditiously and comprehensively, and none other than normally scheduled maintenance is required at this time. The following are some of the issues resolved by Mr. Anaya since the previous inspection on February 24, 2015: . Vegetation control along the face has improved significantly, and is now approaching excellent. Tall and dense bushes and emerging trees along both groins have been cleared to open these important areas to improved monitoring for seepage and other defects. - The local pockets and holes near the base of the concrete-slurry stabilized rock splash apron below the spillway stilling basin have been repaired as requested. . The severely corroded outlet bypass pipe supports and hardware within the control valve vault have been replaced as directed. The severely corroded connection hardware for the 36-inch butterfly valve within the outlet vault was replaced the previous year. Conclusions From the known information and visual inspection, the dam, reservoir, and the appurtenances are judged safe for continued use. Observations and Comments Dam The visible portions of the upstream face, crest, face, and abutments are in satisfactory condition, with no indication of surficial distress or instability. The upstream riprap armor remains in satisfactory condition and continues to provide reasonably adequate protection against wave action. Vegetation control along the face has improved significantly, and is now approaching excellent. Tall and dense bushes and emerging trees along both groins have been cleared to open these important areas to improved monitoring for seepage and other defects. The majority of the embankment is covered in moderately dense ankle to knee tall grass and other moderately low ground cover that provide protection against erosion without preventing effective inspection and monitoring for seepage and other defects. Rodent control remains generally satisfactory though locally abundant indications of burrowing are evident along portions of the crest. Spillway The approach, control section, and exit channel were clear and unobstructed; a polyethylene log boom was in place several hundred feet upstream of the dam. The spillway concrete struc QT Inspected by J. LoweC . Photos taken? Yes No Date of Inspection 5 Aple/Zf?6 cc for Owner/Book Date of Report 6 April 2016 IFI DWR1261 (Rev. 10mg) Sheet 5 INSPECTIOR DAM AND RESERVOIR IN GER STATUS Name of Dam Soulaiule Dam No. 33?9 Date of Inspection 5 April 2016 Observations and Comments Seepage remains in good condition with no obvious signs of distress or deterioration. The concrete-slurry rock splash apron below the stilling basin is also in good condition, and pockets and holes near the base of the apron have been repaired as requested. Large bushes along the lower left spillway wall should probably be trimmed back a bit to prevent possible root damage. Total freeboard is 12 feet and the residual freeboard is 3.3 feet. Freeboard is Satisfactory. Five 36-inch diameter butterfly valves mounted on the inclined inlet structure provides upstream control for the fully encased outiet. The five mechanically operated valves are located at elevations 323.0?, 305.5?, 228.0?, 270.5?, and 253.0?. control is prOvided by a pair of butterfly valves arrayed in series; a 36-inch butterfly valve within a concrete vault, followed by a recentiy installed 48-inch butterfly valve buried between the vault and outlet energy dissipater discharge. The outlet is normally pressurized. The severely corroded outlet bypass pipe supports and hardware within the control valve vault have been replaced as directed. The severeiy corroded connection hardware for the 36- inch butterfly valve within the outlet vault was replaced the previous year. All of the outlet controls were partiaily cycied during this inspection, and all were found to be in good operating order. All outiet controls were fuiiy cycied and found to be in satisfactory operating condition during the February 24, 2015 periodic inspection. No evidence of seepage was observed through the face, groins, or abutments. The seepage monitoring weir next to the right side of the outlet energy dissipating structure has been cleared of sediment and vegetative debris, as requested. Ciear flow through the weir was approximately 10 and is within historic iimits. Instrumentation consists of the foilowing: Twenty-one (21) survey monuments. Survey monuments were installed to measure post construction settlement and to monitor settiement and lateral displacement of the embankment crest and face foilowing significant seismic events. Surveys are performed approximately every five years. a Nineteen (19) piezometers. Piezometers were installed to monitor post construction pore water pressure and to monitor the phreatic surface within the embankment. Piezometers are read monthiy. a One (1) 90~degree V-notch weir. The weir was installed to measure seepage from the toe drain and is monitored The latest instrumentation data was received from the owner on December 16, 2015; survey data covers the reporting period between January 2006 and November 2015. Settlement data shows that the dam continues to settle over time, though along a flattening settlement slope. The maximum differential settlement and the maximum total settlement since the start of the reviewed data period is 0.465 feet (5.6 inches) for monument on 8 October 2015. Settlement at ali locations is significantly less than camber, and camber at monument M-16 is 25 inches. DWR1261(rev.10f09) Sheet 2 of 6 INSPECTION DAM AND RESERVOIR IN GER STATUS Name of Dam Soulajule Dam No. 33~9 Date of inspection 5 April 2016 Observations and Comments Alignment readings are presented and are quite steady up until 1991, after which they make a pronounced shift in the upstream direction beginning in 1992. The upstream shift continues through to the 2015 readings, with maximum total displacements of almost 2 inches between 1991 and 2015. A new survey instrument was introduced in December of 2005, and the change of instrument, reading and reporting errors, or a change in anchor monument locations are the only plausible explanations for the deviations. Several years of consistent data will be required before any meaningful trends can be ascertained, but based on data prior to 1991 the dam remains stable with regard to alignment. Piezometers are distributed along the crest, along a bench near the mid elevation of the embankment, on the upstream face, and along the toe and groin. Design elevations for the piezometers are: Piezometer Depth to Design Comments Number Bottom of Tip Piezometer Elevation P-1 141.33 204.66 Left crest. 1 16.38 229.45 Left crest. -P-1 46.17 299.83 Left crest. P-2 135.83 210.75 Center crest. 156.33 190.10 Center crest. 66.00 280.57 Center crest. P-3 90.46 255.36 Right crest. P-3A 98.33 246.89 Right crest. P-3B 45.08 300.38 Right crest. P-4 86.75 249.50 Upper center embankment. P-5 78.29 231.55 Left drainage bench. Critical elevation 250?. P-6 88.74 224.49 Center drainage bench. Critical elevation 250'. 1 16.76 196.39 Center drainage bench. Critical elevation 250?. 75.79 237.41 Right drainage bench. Critical elevation 250?. P-8 59.85 252.71 Far right drainage bench. Criticai elevation 250?. P-9 28.57 222.58 Left toe. Critical elevation 250?. P-10 43.56 207.56 Center toe. Critical elevation 250?. 38.28 218.71 Right groin. Critical elevation 250?. 28.07 313.07 Upper center upstream embankment. Measured piezometer water surface elevations remain relativeiy constant over the period reviewed, and all piezometers remain below the critical elevation indicated in the Embankment Dam Stability Analysis, Soulajule Dam, 33-9, dated 28 February 1978. The seepage measurement weir is located on the right side of the outlet energy dissipater, and is designed to measure seepage from the toe drain. Data for the period January 2006 through July 2015 was reviewed prior to this inspection. Clear seepage measured at the monitoring weir correlates closely to rainfall; in the absence of rainfall seepage drops to essentially zero. Normal peak seepage of up to 70 or more gpm, quickly falls to near zero following the termination of winter storms. Seepage during this inspection was on the order of 2 to 3 gpm. Seepage reported was consistent with historic values and shows a trend to decreasing over time; probably the result of the past several years of drought. DWR1261(rev.10709} Sheet 3 of 6 INSPECTION DAM AND RESERVOIR IN CERT STATUS Name of Dam Soulajule Dam No. 33-9 Date of Inspection 5 April 2016 Observations and Comments In their December '16, 2015 instrumentation data submittal letter the owner reports, "The Soulajule Dam piezometer readings are consistent with historic readings. The weir readings vary due to clogging and flooding. The weirs are now cleaned every six months as a part of a preventive maintenance program. Soulajule Dam is trending toward stabilization: settlement of -0.47 ft (maximum) and alignment of +0.18 ft upstream direction; maximum). Based on the data submitted the darn appears to be performing satisfactorily, and no additional instrumentation is believed necessary at this time. The crest and upstream face as viewed from the right spillway wall. The small bushes in the foreground have re-emerged after having been out earlier in the year. Sheet 4 of 6 INSPECTIOI aF DAM AND RESERVOIR IN CER STATUS Name of Dam Soulajule Darn No. 33-9 Date of Inspection 5 April 2016 .. 7. Vegetation control along the face has improved significantly (above and below), and is now approaching excellent. The right groin and left spillway wall could use a bit more work (outlined below and on the next page), but beyond that all is near perfect. Fw?- DWR 1261 (rev. 10(09) Sheet 5 0f DAM AND RESERVOIR IN CER STATUS Name of Dam Soulajule Dam No. 33?9 Date of Inspection 5 April 2016 - . (I Abr-i??iLu The severely corroded outlet bypass pipe supports and hardware (circled) within the control valve vault have been replaced as directed. Sheet 6 of 6 STATE OF CALIFORNIA CALIFORNIA NATURAL RESOURCES AGENCY DEPARTMENT OF WATER RESOURCES DIVISION OF SAFETY OF DAMS INSPECTION OF DAM AND RESERVOIR IN CERTIFIED STATUS Name of Dam Soulajule Darn No. 33?9 County Marin Time of Dam ERTH Type of Spillway Concrete weir and chute Water is 0.1 feet below the spillway crest and 12 feet below the dam crest. Weather Conditions Clear and mild Contacts Made Alex Anaya and Ben Bauer during the inspection Reason for Inspection Periodic outlet valve cycling and evaluation Important Observations, Recommendations or Actions Taken This inspection was limited to observation of the cycling of, and evaluation of, the upstream and outlet controls. There have been no substantive changes in the condition of the dam and appurtenances since the previous annual inspection performed on October 30, 2014. Observations, recommendations, or actions concerning the embankment and its appurtenances are presented in the October 30, 2014 inspection report, the contents of which are not repeated here. Some of the outlet bypass pipe support hardware within the control valve vault is moderately to severely corroded. The owner needs to inspect the hardware, protect what can be salvaged, and replace that hardware that has deteriorated to the degree it is no longer safe for use. Conclusions From the known information and visual inspection, the dam, reservoir. and the appurtenances are judged safe for continued use. Observations and Comments Outlet Five 36-inch diameter butterfly valves mounted on the inclined inlet structure provide upstream control for the fully encased outlet. The five mechanically operated valves are located at elevations 323.0?, 305.5?, 288.0', 270.5', and 253.0?. control is provided by a pair of butterfly valves arrayed in series; a 36?inch butterfly valve within a concrete vault, followed by a recently installed 48-inch butterfly valve buried between the vault and outlet energy dissipater discharge. The outlet is normally pressurized. All upstream and controls were fully cycled with the aid of a handheld E.H. Wachs P-2 hydraulic power head. The power head rotates at between 0?12 RPM, and applies a maximum torque of 800 ft-Ibs. Rotational speed during the valve cycling at Soulajule Dam averaged roughly 4.5 RPM. Each of the upstream controls require 175 turns to fully open or fully close the valve, and each of the controls require 217 turns to fully open or close. All valves operated well and appear to be in good operating condition. Some of the outlet bypass pipe supports and hardware within the control valve vault is moderately to severely corroded. The owner needs to inspect the hardware, protect what can be salvaged, and replace that hardware that has deteriorated to the degree it is no longer safe for use. . I y? 2 1 sum" Inspected by Photos taken? Yes No_ Date of Inspection 24February 2015 1' (Ill co for Owner/Book Date of Report 27 Fabruary 2015 I DWR 1261 (Rev. iorosvol? INSPECTIOB DAM AND RESERVOIR IN CER. .FIED STATUS Name of Dam Soulajule Dam No. 33-9 Date of Inspection 24 February 2015 Operating the 36-inch diameter upstream outlet control number 5 butterfly valve, above, and the most 48-inch butterfly valve, below. DWR 1261 (rev. 10:09) Sheet 2 of 4 INSPECTIO. DAM AND RESERVOIR IN CEix. IFIED STATUS Name of Dam Soulajule Dam No. 33~9 Date of inspection 24 February 2015 #7 - ??33 .. <15? Alt/g) I?ll?? Ir; In: '1 {fa/d/II/1Operating the 36- inch outlet control butterfly valve within the concrete vault, above). The hardware for the valve which resides below the metal floor grate (below) was replaced withn the last year. .1 ?"mm I I DWR 1261 (rev. 10I09) Sheet 3 of INSPECTIO. DAM AND RESERVOIR IN CER I STATUS Name of Dam Soulajule Dam No. 33-9 Date of Inspection 24 February 2015 - - 4.649%: I '26? fer/57? 4-4 1.. Some of the outlet bypass pipe supports and hardware within the control valve vault is moderately to severely corroded (above and below). The owner needs to inspect the hardware, protect what can be salvaged, and replace that hardware that has deteriorated to the degree it is no longer safe for use. DWR 1261 (rev. 10:09) Sheet 4 of 4 STATE OF CALIFORNIA JALIFORNIA NATURAL RESOURCES AGENCY DEPARTMENT OF WATER RESOURCES DIVISION OF SAFETY OF DAMS INSPECTION OF DAM AND RESERVOIR IN CERTIFIED STATUS Name ofDam Soulajule Dam No. 33-9 County Marin Type of Darn Earth Type of Spillway Concrete Weir and Chute Water is ~12 feet below spillway crest and ~24 feet below darn crest. Weather Conditions Sunny and mild Contacts Made Carl Gowan before and Alex Anaya, Ben Bauer, Carl Sanders during the inspection Reason for Inspection Periodic Maintenance Inspection Important Observations, Recommendations or Actions Taken None of the controls was cycled during this inspection. All upstream and controls were fully cycled during the August 22-23, 2013 inspection which was exclusively scheduled to observe the outlet control operation. As requested during the previous inspection, I reiterated that severely corroded hardware of the controls, including nuts and bolts, localized portions ofthe pipe, and their supports, etc. be repainted or replaced. The owner needs to inspect the hardware, protect what can be salvaged, and replace those that have deteriorated to the degree they are no longer safe for use. There are no prior outstanding administrative requirements. The total class weight of 20 appears satisfactory. Conclusions From the known information and visual inspection, the dam, reservoir, and the appurtenances are judged safe for continued use. Observations and Comments Dam The visible portions of the upstream face, crest, face, and abutments are in satisfactory condition, with no indication of surficial distress or instability. The upstream riprap armor remains in satisfactory condition and provides adequate protection against wave action. Vegetation control is satisfactory. No major woody vegetation was noted on the embankment, groins, or dam toe except for emerging bushes as highlighted in Photos 2 and 3 and which need to be removed. The majority of the dam face is covered with low beneficial grass that provides protection against erosion and that permits inspection and monitoring for seepage and other defects. In general, rodent control remains satisfactory as no major rodent activity was noted on the . embankment. Spillway With the exception of minor brush in the approach area (Photo 1), the approach, control section, and exit channel were clear and unobstructed; a polyethylene log boom was in place several hundred feet upstream ofthe dam. This brush should be removed as part of vegetation control. The spillway structure concrete remains in satisfactory condition with no obvious signs of distress or deterioration. The current design storm, prepared in 1978, is for a 10,000-year return period producing 15,223 (~814 sq mi) from the 18. 7- ?square m?ile drainage area. The spillway capacity is ~17, 300 which is greater than the peak inflow. Total freeboard Is 12 feet and the residual design storm is 3 3 feet. The freeboards are satisfactory. - 332-- 21: a 6' lnspected by :41 r. Photos taken? Yes N0 Date of Inspection 10/30/2014 kl/jidlg; cc for Owner/Book Date of Report 11/21/2014 owa 1251 (Rev. 10/09) Sheet 1 of 5 INSPECTION DAM AND RESERVOIR IN GER ED STATUS Name ofDam Soulajule Dam No. 33-9 Date of Inspection 10/30/2014 Observations and Comments Outlet Five 36-inch diameter butter?y valves mounted on the inclined inlet structure provide upstream control for the fully encased outlet. The five mechanically operated valves are located at elevations 323.0?, 305.5?, 2&80?, 270.5?, and 253.0?. control is provided by a pair of butterfly valves arrayed in series; a 36?inch butterfly valve within a concrete vault, followed by a recently installed 48-inch butterfly valve buried between the vault and outlet energy dissipater. The outlet is normally pressurized. None of the controls were cycled during this inspection. All upstream and controls were fully cycled during the August 22-23, 2013 inspection which was exclusively scheduled to observe the outlet control operation. As requested during the previous inspection, I reiterated that severely corroded hardware of the controls, including nuts and bolts, localized portions of the pipe, and their supports, etc. be repainted or replaced. The owner needs to inspect the hardware, protect what can be salvaged, and replace those that have deteriorated to the degree they are no longer safe for use. No evidence of seepage was observed through the dam face, groins, or abutments except for the measured seepage at the v-notch weir located to the right side of the outiet energy dissipating structure. The flow was clear with no indication of any turbidity. Instrumentation consists of the following: Twenty-one (21) survey monuments. Survey monuments were installed to measure post construction settlement and to monitor settiement and lateral displacement of the embankment crest and face following significant seismic events. Surveys are performed approximately every five years. Nineteen (19) piezometers. Piezometers were installed to monitor post construction pore water pressure and to monitor the phreatic surface within the embankment. Piezometers are read One (1) 90-degree V-notch weir. The weir was installed to measure seepage from the toe drain and is monitored The most recent instrumentation report was transmitted on September 24, 2014 and the report includes a brief evaluation of the data. Piezometers: Ten year (2005-2014) plots are included in the data. All piezometers, consistent with the previous year readings, are generally responding to the reservoir water elevation. No apparent adverse trends are evident for any of the piezometers. Seepage: Ten year seepage piot is included in the report. Seepage is generally responding to the reservoir water level and rainfall. For the earlier years of the plot, 2005-2010, seepage ranged between 0-75 and in the later years (2010-2014), seepage was relatively stabie and varied between 0-25 gpm. The owner attributes the variationsin the seepage to clogging and fiooding of the weir. The owner has started cleaning the weir every six months as a part of preventive maintenance program. Survey Monuments: There are 21 survey monuments located on the dam. The most recent survey was performed in September 2014 and the data is present in plots and tables. Review of the data Sheet 2 of 5 INSPECTION DAM AND RESERVOIR IN CER ED STATUS NameofDam Soulajule Dam No. 33-9 Date of Inspection 1 0/ 30/ 201 4 Observations and Comments and plots (long term plots, 1980-2014) show that the embankment is trending towards stabilization with no noticeable movement at any of the monuments. Overall the existing instrumentation and their reading frequencies are judged adequate at this time. 1. A View of the spillway weir as seenfrom heappoch area within the reservoir. Circled brush needs to be removed. DWR1261(rev.10109) Sheet 3 of 5 INSPECTION DAM AND RESERVOIR CER ED STATUS NameofDam Soulajule Dam No. 33-9 Date of Inspection 10/30/2014 ., "View of the embankment. The owner should continue eradicating plethora of bushes emerging in the circled areas. DWR1261(rev.10f09) Sheet 4 of 5 DAM AND RESERVOIR IN CEF ED STATUS Name ofDam Soulajule Dam No. 33-9 Date of Inspection 10/30/2014 - qp?auhm-O 1-All.41. 'l l..v 4. A recently installed aerator of the outlet structure to enhance oxygen saturation in the released water to improve the health of endangered aquatic species in the creek. DWR 1261 (rev. 10/09) Sheet 5 0f 5 STATE OF CALIFORNIA CALIFORNIA NATURAL RESOURCES DEPARTMENT OF WATER RESOURCES DIVISION OF SAFETY OF DAMS INSPECTION OF DAM AND RESERVOIR IN CERTIFIED STATUS Name of Dam SOUIajule Dam No. 33-9 County Marin Type of Dam ERTH Type of Spillway Concrete weir and chute Water is 5 feet below the spillway crest and 17 feet DGIOW the darn crest. Weather Conditions Overcast and cool Contacts Made Frank Figone during the inspection Reason for Inspection Periodic outlet valve cycling and evaluation Important Observations. Recommendations or Actions Taken This inspection was limited to observation of the cycling of, and evaluation of, the upstream and outlet controls. Observations, recommendations, or actions concerning the embankment and its appurtenances are presented in the April 24. 2013 inepecticn report, the contents of which are not repeated here. The connecting hardware for the 36-inch control butterfly valve located within the concrete vault is moderately to severely corroded. The owner needs to inspect the hardware, protect what can be salvaged, and replace that hardware that has deteriorated to the degree it is no longer safe for use. Conclusions From the known information and visual inspection, the dam, reservoir, and the appurtenances arejudged safe for continued use. Observations and Comments Outlet Five 36-inch diameter butterfly valves mounted on the inclined inlet structure provide upstream control for the fully encased outlet. The five mechanically operated valves are located at elevations 323.0?, 305.5?, 288.0', 270.5?, and 253.0?. control is provided by a pair of butterfly valves arrayed in series; a 36-inch butterfly valve within a concrete vault, followed by a recently installed 48-inch butterfly valve buried between the vault and outlet energy dissipater discharge. The outlet is normally pressurized. All upstream and controls were fully cycled and found to be in satisfactory operating condition. The upstream controls were fully cycled with the aid of a handheld E.H. Wachs hydraulic power head which rotates at between 0-12 RPM, and applies a maximum torque of 800 ft-lbs. Rotational speed during the valve cycling at Soulajule Dam averaged roughly 6 to 7 RPM. The upstream control valves all function properly and appear to be in good operating condition. Each of the two control butterfly valves requires 217 turns to fully open or fully close the valve. The 48-inch valve is turned manually; the 36-inch valve within the concrete vault is turned with the aid of the Wachs power head. Both valves function properly, but the connecting hardware for the valve within the vault is moderately to severely corroded. The owner needs to inspect the hardware, protect what can be salvaged, and replace that hardware that has deteriorated to the degree it is no longer safe for use. Lay?? ZA 1h; 26"; inspected by J. Lowe Photos taken? YES No Date of inspection 22-23 August 2013 cc for Owner/Book Date of Report 29 August 2013 M) Q.) DWR 1261 (Rev. 10mg) Sheet 1 of ISMI If? We Cr/s/rs INSPECTIOL DAM AND RESERVOIR IN STATUS Name of Darn Soulajule Dam No. 33~9 Date of Inspection 29 August 2013 Five 36-inch diameter butterfly valves mounted on the inclined inlet structure provide upstream control for the fully encased outlet. The upper most valve can be seen at the upper left of the photograph. DWR1261(rev.10f09) Sheet 2 of 5 INSPECTIO. 7 DAM AND RESERVOIR IN IED STATUS Name of Dam Soulajule Dam No. 33-9 Date of Inspection 29 August 2013 The upstream controls were fully cycled with the aid of a handheld E.H. Wachs hydraulic power head; rotational speed during the valve cycling at Soulajule Dam averaged roughly 6 to 7 RPM. The upstream control valves all function properly and appear to be in good Operating condition. .. . .- Each of the two control butterfly valves requires 217 turns to fully open or fully close the valve. The 48?inch valve is turned manually (above). DWR1261(rev.10r09) Sheet 3 of INSPECTIOL DAM AND RESERVOIR IN 05' ED STATUS Name of Dam Soulajule Dam No. 33-9 Date of inspection 29 August 2013 . if ?1 7" a i . ful?l-15k} i . .7 . -I. Hill-.?xme . .. The 36-inch upstream control butterfly valve within the concrete vault is turned with the aid of the Wachs power head. The connecting hardware for the valve within the vault is moderately to severely corroded (below). 3' Sheet 4 of 5 INSPECTIO DAM AND RESERVOIR IN STATUS Name of Dam Soulajule Dam No. 33-9 Date of Inspection 29 August 2013 . ., . . Corrosion is a ubiquitous problem within the outlet control concrete vault. The outlet pipe shows evidence of the start of severe pitting (above), and a number of the fish water bypass pipe supports have been essentially destroyed by corrosion (below). Improved maintenance practices can extend the useful life of costly to replace components. DWR1261(rev.10l09) Sheet 5 of 5 STATE OF CALIFORNIA CALIFORNIA NATURAL RESOURCES AGENCY DEPARTMENT OF WATER RESOURCES DIVISION OF SAFETY OF DAMS INSPECTION OF DAM AND RESERVOIR IN CERTIFIED STATUS Name of Darn Soulajule Darn No. 33-9 County Marin Type of Dam ERTH Type of Spillway Concrete weir and chute Water is 5 feet below the spillway crest and 17 feet below the dam crest. Weather Conditions Clear and mild Contacts Made Carl Gowan and Carl Sanders during the inspection Reason for inspection Periodic Evaluation Important Observations. Recommendations or Actions Taken Vegetation control along the face needs improvement, and tail and dense bushes and emerging trees along both groins need clearing to open these important areas to improved monitoring for seepage and other defects. Mr. Sanders has begun to clear bushes from the face and groins, but much work remains before they are sufficiently clear to permit unimpeded access for effective inspection and monitoring. The concrete?slurry stabilized rock splash apron below the Spillway stilling basin is in generally good condition, but local pockets and holes near the base of the apron should be repaired before they become a much more significant and expensive maintenance concern. There are no prior outstanding administrative requirements. The total class weight of 20 appears satisfactory. Conclusions From the known information and visual inspection, the dam, reservoir, and the appurtenances are judged safe for continued use. Observations and Comments Dam The visible portions of the upstream face, crest, face, and abutments are in satisfactory condition, with no indication of surficial distress or instability. The upstream riprap armor remains in satisfactory condition and continues to provide reasonably adequate protection against wave action. Vegetation control along the upstream face is generally satisfactory, and only a few young trees and bushes require removal. Vegetation control along the face needs improvement, and tall and dense bushes and emerging trees along both groins need clearing to open these important areas to improved monitoring for seepage and other defects. Mr. Sanders has begun to clear bushes from the face and groins, but much work remains before they are sufficiently clear to permit unimpeded access for effective inspection and monitoring. Rodent control remains generally satisfactory though locally abundant indications of burrowing are evident along portions of the crest. Spiilway The approach, control section, and exit channel were clear and unobstructed; a polyethylene log boom was in place several hundred feet upstream of the dam. The spillway concrete structure remains in good condition with no obvious signs of distress or deterioration. The concrete?slurry stabilized rock splash apron below the stilling basin is also in generally good condition, but local pockets and holes near the base ofthe apron should be repaired before they become a much more significant and expensive maintenance concern. 'v Lou/L. 26 197?" 2013 Inspected by J. Lowe . Photos taken? Yes N0 Date of Inspection 24 April 2013 Mb cc for Owner/Book Date of Report 26 April 2013 5gp] 3, I. DWR 1261 (Rev.10r09) Sheet 1 MM OF DAM AND RESERVOIR IN CERTIFIED STATUS Name of Dam Souiajule Dam No. 33-9 Date of Inspection 24 April 2013 Observations and Comments Outlet Seegage instr. Total freeboard is 12 feet and the residual freeboard is 3.3 feet. Freeboard is satisfactory. Five 36?inch diameter butterfly valves mounted on the inclined inlet structure provides upstream control for the fully encased outlet. The five mechanically operated valves are located at elevations 323.0?, 305.5?, 228.0?, 270.5?, and 253.0?. control is provided by a pair of butterfly valves arrayed in series; a 36-inch butterfly valve within a concrete vauit, followed by a recently installed 48-inch butterfly valve buried between the vault and outlet energy dissipater discharge. The outlet is normally pressurized. None of the outlet controls were cycled during this inspection but they are scheduled to be cycled later in the year. All upstream and controls were fully cycled and found to be in satisfactory operating condition during the July 2009 periodic inspection. No evidence of seepage was observed through the face, groins, or abutments. The seepage monitoring weir next to the right side of the outiet energy dissipating structure remains partially filled with sediment and vegetative debris. Estimated flow was approximateiy 5 to 10 gpm. Instrumentation consists of the following: Twenty-one (21) survey monuments. Survey monuments were installed to measure post construction settlement and to monitor settlement and lateral displacement of the embankment crest and face following significant seismic events. Surveys are performed approximately every five years. a Nineteen (19) piezometers. Piezometers were installed to monitor post construction pore water pressure and to monitor the phreatic surface within the embankment. Piezometers are read 0 One (1) 90-degree V~notch weir. The weir was installed to measure seepage from the toe drain and is monitored Survey monuments are distributed along the crest and along the bench near the mid elevation of the embankment. Data for the period between January 1980 and March 2011 was reviewed prior to this inspection. The maximum differentiai settlement since the start of the reviewed data period is 0.409 feet (4.9 inches) for monument M-16 on 17 March 2011. The maximum total recorded settiement is 0.445 feet, or 5.3 inches, also at monument M-16. Alignment readings are presented and are quite steady up until 1991, after which they make a pronounced shift in the upstream direction beginning in 1992. The upstream shift continues through to the 2011 readings, with maximum total displacements of almost 2 inches between 1991 and 2011. A new survey instrument was introduced in December of 2005, and the change of instrument, reading and reporting errors, or a change in anchor monument-locations are the only plausible explanations for the deviations. Several years of consistent data wilt be required before any meaningful trends can be ascertained, but based on data prior to 1991 the dam remains stable with regard to alignment. Piezometers are distributed along the crest, along a bench near the mid elevation of the embankment, on the upstream face, and along the toe and groin. Design elevations for the piezometers are: DWR1261(rev.10i09) Sheet 2 of 6 INSPECTION OF DAM AND RESERVOIR IN CERTIFIED STATUS Name of Dam Soulajuie - Dam No. 33?9 Date of inspection 24 April 2013 Observations and Comments Piezometer Depth to Design Comments Number Bottom of Tip Piezometer Elevation P-1 141.33 204.66 Left crest. P-1A 116.38 229.45 Left crest. P-1 46.17 299.83 Left crest. 135.83 210.75 Center crest. 156.33 190.10 Center crest. P-2B 66.00 280.57 Center crest. P-3 90.46 255.36 Right crest. P-3A 98.33 246.89 Right crest. P-3B 45.08 300.38 Right crest. P-4 86.75 249.50 Upper center embankment. P-5 78.29 231.55 Left drainage bench. Critical elevation 250?. P-6 88.74 224.49 Center drainage bench. Critical elevation 250?. P-6A 116.76 196.39 Center drainage bench. Critical elevation 250?. 75.79 237.41 Right drainage bench. Critical elevation 250?. 59.85 252.71 Far right drainage bench. Critical elevation 250?. P-9 28.57 222.58 Left toe. Critical elevation 250'. P-10 43.56 207.56 toe. Critical elevation 250?. P-11 38.28 218.71 Right groin. Critical elevation 250?. P-12 28.07 313.07 Upper center upstream embankment. Measured piezometer water surface elevations remain relatively constant over the period reviewed, and all piezometers remain below the critical elevation indicated in the Embankment Dam Stability Analysis, Soulajuie Dam, 33-9, dated 28 February 1978. The seepage measurement weir is located on the right side of the outlet energy dissipater, and is designed to measure seepage from the toe drain. Data for the period January 2001 through January 2011 was reviewed prior to this inspection. Measured seepage rates have varied from near zero to as high as just under 100 in March of 2002; the high value apparently the result of a combination of seepage and surface runoff following a period of intense rainfall. More typical readings in the absence of significant contribution from rainfail are in the range of 10 or less. Seepage during this inspection was on the order of 2 to 3 gpm. With the exception of the new historic high reported for March 2002, seepage reported was consistent with historic values and shows no obvious indications of increasing over time. in their April 12, 2012 instrumentation data submittal letter the owner reports, r?The Soulajule Dam piezometer readings are consistent with historic readings. The weir readings vary due to clogging and flooding. The weirs are now cleaned every six months as a part of a preventive maintenance program. Soulajule Dam is trending toward stabilization: settlement of -0. 43 ft (maximum) and alignment of 16 ft (upstream direction; maximum). I found no-concerning trends within the data reviewed, and based on the data the dam appears to be performing satisfactorily. DWR 1261 (rev. 10mg) Sheet 3 of 6 INSPECTION OF DAM AND RESERVOIR IN CERTIFIED STATUS Name of Dam Soulajule Dam No. 33-9 Date of Inspection 24 April 2013 . . - Vegetation control along the upstream face is generally satisfactory, and only a few young trees and bushes require removal. Vegetation control along the face needs improvement, and tall and dense bushes and emerging trees along both groins need clearing to open these important areas to improved monitoring for seepage and other defects. DWR1261 (rev. 10109) Sheet 4 of 6 INSPECTION OF DAM AND RESERVOIR IN CERTIFIED STATUS Name of Dam Soulajule Dam No. 33?9 Date of Inspection 24 April 2013 . . . .. - The lower left groin also requires clearing, but fortunately the extent of clearing required is much less than that of the right groin. DWR 1261 (rev. 10f09) Sheet 5 of 6 INSPECTION OF DAM AND RESERVOIR IN CERTIFIED STATUS Name of Dam Darn No. 33-9 Date of Inspection 24 April 2013 The spillway and concrete-slurry stabilized rock splash apron below the stilling basin are in generally good condition (above), but local pockets and holes near the base of the apron should be repaired before they become a much more significant and expensive maintenance concern (below). To prevent root damage to the spillway and apron large trees and bushes should be kept clear of the structures (above, circled). .. . . DWR1261(rev.10l09) Sheet 6 of 6