Feasibility of Fish Passage at Alameda Creek Diversion Dam

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Feasibility of Fish Passage at Alameda Creek Diversion DamTable 5-1Capital Costs of ACDD Passage Design ComponentsComponent Raw Cost 1 (100%) Cost 3Soft CostsandDesignContingencyTotal CapitalLong Fishway $5,251,000 $5,251,000 $10,502,000Confluence FishFacility $803,000 $803,000 $1,606,000Camp Ohlone HaulRoute $3,270,000 $3,270,000 $6,540,000Fish Screens $6,610,000 $6,610,000 $13,220,000Notes:1Back-up for raw cost shown in Appendix A.2100% factor includes the following: (a) Estimate Contingency 25%, (b) ConstructionEscalation 24%, (c) Construction Contingency 10%, and (d) Soft Costs 41% (SFPUC,2006).3Order-of-magnitude costs estimated are based on current rates in 2009 dollars.A number of limitations are associated with the estimates provided. The costs are preliminary, orderof-magnitude8 estimates to assist in the comparison of relative costs among options. No engineeringsite work or calculations have been performed. Depending upon geotechnical and hydrologicalconditions at the site, it may not be feasible to construct certain components as assumed. In addition,environmental impact mitigation costs could be required with implementation of some or all options.These mitigation costs are not included in this estimate.5.2 LOST WATER DIVERSION COST ESTIMATIONBecause SFPUC is a supplier of municipal water, reductions in the amount of water diverted atACDD to Calaveras Reservoir will result in most cases in a cost for replacement water. Therefore, acomponent of the annual fish ladder and screen operating costs is the lost water diversion opportunitycosts. The water potentially unavailable for diversion to Calaveras Reservoir with theimplementation of fish passage could include:■ A reduction in diversion capacity due to screening (Section 5.2.1)■Water bypassed at a fish screen to maintain required sweeping flows and downstream passage(Section 5.2.2)■ Water bypassed to operate a fish ladder (Section 5.2.3)These lost water diversion opportunities are described in more detail in this section, and estimates areprovided for the costs associated with each lost water diversion opportunity, along with associatedassumptions and limitations (Section 5.2.4).8 An order-of-magnitude cost estimate is also known as a concept Class 5 estimate (AACE, 2005). Its primary use andpurpose is to screen alternatives and determine feasibility. Expected accuracy ranges from –20% to –50% on the lowend, and +30% to +100% on the high end.ACDD Passage June 2009 Page 5-2
5.0 Capital and Operating and Maintenance Costs5.2.1 REDUCTION IN DIVERSION CAPACITY DUE TOSCREENINGThe capacity of the ACDT to transfer water to Calaveras Reservoir would likely be reduced if screeningwas implemented according to the criteria described by NMFS (1997 and 2008) and CDFG (2009). Ingeneral, fish screening criteria include a combination of (1) low approach velocity, and (2) adequatesweeping velocity. Approach velocity is defined as the velocity of water that passes through a screeningdevice perpendicular to the screen openings. Sweeping velocity is the velocity of water that runsparallel to the screen openings. At ACDD, the sweeping velocity requirement would be met byproviding a fish screen bypass at the downstream end of the screens. Water costs associated with thefish screen bypass are addressed in Section 5.2.2. The purpose of this section is to quantify reductionsin the amount of water that could be diverted to Calaveras Reservoir due to potential reductions in themaximum rate at which water could be diverted through the ACDT, if screening was implemented.The current maximum diversion rate through the ACDT is estimated to be approximately 650 cfs. Whenscreens are used, an approach velocity of 0.33 fps 9 is typically required by CDFG (2009) to protect fishfrom impingement. NMFS (1997 and 2008) also has approach velocity criteria, which vary dependingupon site specifics. At ACDD, NMFS criteria would be less restrictive than CDFG’s (2009), so theCDFG criterion is used for the purposes of analysis in this memorandum. Approach velocity anddiversion rate are related to screen area; for a given rate of diversion, a larger screen area will result in alower approach velocity. Alternatively stated, for a given approach velocity, increasing the screen areaincreases the maximum potential diversion rate, as shown on Figure 5-1. Therefore, a primary constraintduring screen design is the size of screen that a site can accommodate. Because of the site constraints and2500Screen Area in square feet20001500100050000 100 200 300 400 500 600 700 800Flow in CFSFigure 5-1Flow versus Required Screen Area9 The screen approach velocity at ACDD would be determined in coordination with NMFS and CDFG.ACDD Passage June 2009 Page 5-3
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T E C H N I C A L M E M O R A N D U
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Feasibility of Fish Passage at Alam
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Page 11 and 12: 1.0 Introduction1 INTRODUCTION1.1 B
Page 13: 24Alamo680DanvilleAlameda CreekWate
Page 16 and 17: Feasibility of Fish Passage at Alam
Page 18 and 19: oleyriesSanCalaveras Creekalaveras
Page 20 and 21: (a)(b)Alameda Creek Diversion Dam (
Page 23 and 24: 2.0 Setting2.3.2.1 ALAMEDA CREEK DI
Page 25 and 26: 2.0 Settingalmost never submerged;
Page 27 and 28: 2.0 SettingRainbow trout are the sa
Page 29: 2.0 SettingA number of future proje
Page 42 and 43: (a) A view of the navigation lock a
Page 44 and 45: (a) A pickup truck adapted for haul
Page 57: Approximately 1.8 miles toCalaveras
Page 77 and 78: 6.0 Additional Considerations and A
Page 79: 6.0 Additional Considerations and A
Page 89 and 90: 9.0 Report Preparation9 REPORT PREP
Page 91 and 92: 10.0 References10 REFERENCESAACE (A
Page 93 and 94: 10.0 ReferencesHayes, Darrel, 2001.
Page 95 and 96: 10.0 ReferencesSak, B., San Francis
Page 97: 10.0 ReferencesWDFW (Washington Dep
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Feasibility of Fish Passage at Alameda Creek Diversion Dam

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