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HomeMy WebLinkAboutAPA12I I I I I I I I I I I I I I .-;::;i' .. ~~. ,' '·'. '")- R&M CONSULTANTSJJ INC .. 1E t\U::U\,1£ .. 'f·. O!i G£ OlOr'H~TS P:.t.AN'\'~f A!~ SU~V.( .. ¥t'J~l;·~ I I I G=D&iru(g~ 0 1§00£®©@ Susitna Joint Venture Document Number Please Return To DOCUMENT CONTROL SUSITNA HYQROELECTRIC PROJECT PLAN OF STUDY TASK 2 ACCESS ROADS SUBTASK 2.10 INTERIM REPORT #1 ALTERNATIVE ACCESS CORRIDOR SELECTION Prepared· For: ALASKA POWER AUTHORITY and ACRES AMERICAN, INCORPORATED PreparE!d By: R&M CONSULTANTS, ~NC. DECEMBER 1980 RECEIVED MA.Y 0 5 1983 HARZA-EBASCO Susitna Joint Venture [M]£00~& 0 [g(ID£®©@ Susitna Joint Venture Do!'ument Number \~ Please Return To DOCUMENT CONTROL j 'l i I ! ,i I l l l ! l I l I l I I I I I I I l l 1 I l l ·. CONTENTS APPENDIX A PROPOSED CORRIDOR MAPS APPENDIX B SUMMARY OF ALTERNATIVE COMPARSION APPENDIX C CORRESPONDENCE TO DATE ·. SUSITNA HYDROELECTRIC PROJECT ACCESS ROADS INTERIM REPORT #1 ALTERNATIVE ACCESS CORRIDOR SELECTION A. iNTRODUCTION The Susitna Hydroelectric Project has been under study for some time. The U.S. Corps of Engineers has done extensive work on the project but progress was slow. In late 1979 the Alaska Power Authority selected Acres American 1 Incorporated 1 to conduct feasibility studies and prepare the FERC license application if the project was determined to be feasible. Subtask 2.10 of the plan of study is the location study necessary to determine the most desirable location for an access route and the most economical transporation mode or modal split. R&M Consultants has been selected as a subconsultant to Acres American 1 Incorporated to conduct the access study and other tasks. The plan of study calls for analysis of three general routes to provide access to potential dam sites. In addition consideration must be given to using road, rai I road or a combination of both to serve the project. This report is presented for the purpose of documenting the methods by which the three recommended route corridors were selected. B. SUMMARY The study to date has been held to definition of well defined general corridors within the broad General corridors discussed in susi4/j .. 1 - ! I i l' I l l 1- l .. ·. . the plan of study, and which still satisfy the requirements of the plan of study with regard to location. Alignment design criteria were proposed to Acres American. The response to the proposed criteria was a request to use more stringent design criteria generally conforming to primary highway design criteria. Using this criteria cl number of possible alignments were sketched on one-inch to tht~ mile contour maps. All alternatives were designed to serve both the Devils Canyon and the Watana Dam sites. Other potential dam sites could be served with only minor changes if other sites should prove to be desirable. All alternatives were compared and the three routes showing the most advantageous gr·ade, alignment and length characteristics were recommended for photography. As an additional check the three most promising corridors were f}own by helicopter to provide th~ project team with a close look at actual ground conditions. The three most promising corridors are shown in Appendix A. These three corridors allow consideration of a number of trans- poration alternative plans including certain attractive stage con- struction and modal split options. These options wi II be examined in detail during later phases of the access study. It is recom- mended that Alternates A, B, C and R as detailed on page 13 of this report be approved as the selected access corridor alignments and that these provide the basis for all further access studies. The proposad railroad alignment is within the limits o1' corridor 2 as recommended and must be considered as a viable alternative at this time. C. DESIGN PARAMETERS In order to be able to make a valid comparison oetween alterna- tives a basis for that comparison must be estabHshed, with this I thought in mind, proposed design ci riteria were deveioped and susi4/j - 2 - I i l I l l t I' [ 1 t l l t t I 1 j f I l ·. submitted to Acres American. The criteria submitted are shown in Table 1. TABLE 1 ORIGINAL PROPOSED DESIGt .. CRITERIA Design Speed Maximum Grade Maximum Curvature Design Loading Road 30 mph 10% HS-20 Railroad N/A 2.5% 10° E 50 Design criteria such as these are used to establish guidelines for design, The designer normally attempts to provide hot"izontal and vertical alignment that is better than the mimimum alignment such limits would provide. In order to maintain a schedule and have possible corridors identified for photography, work began on a number of possible alignments prior to approval of the proposed criteria. While the corridor definition work was in progress corre- spondence was t1 eceived asking that roadway criteria be adopted that would essentially conform to a 50-60 mile per hour design speed. The recommended design parameters for the railroad were accepted. Later correspondence from Acres Amel"ican confirmed roadway design criteria for 60 mile per hour design speed. The relatively high roadway design parameters are required because of the size and weight of certain components of the dams that must be manufactured and imported to the site. The required para- meters are given in Table 2. TABLE 2 APPROVED ROADWAY DESIGN PARAMETERS Design Speed 60 mph Maximum Grade 6% Maximum Curvature 5° Design Loading 80 Kip Axle & 200 Kip total (Construction Period) Design Loading HS-20 (After Construction) susi4/j - 3 - I I l j I I ·. APPROVED RAILROAD DESIGN PARAMETERS Maximum Grade Maximum Curvature Loading D. STUDY PROCEDURE 2.5% 10° E-50.* The Sustina Hydroelectric Project is located on a section of the Susitna River that is remote wilderness. Earlier studieu by govern- ment agencies had generated some contour mapping in the vicinity of the proposed dam sites. The only other available contour information was USGS mapping on a one-inch (1 11 ) equals one (1) mile scale with one-hundred foot (100') contour intervals. To aid the project team in selecting possible routes a low level helicopter flight was made in late March, 1980. A mosaic was then made of the USGS mapping from Gold Creek and the Parks Highway through the Watana site and out to the Denali Highway north of Watana. Using the preliminary design parameters and information gained from the overflight of the project area, a number of possible alignments were laid out on the map mosaic. The various alternatives were spnt into convienent segments. Some of these segments were unique while others could be common to two (2) or more alternatives. Each segment was analized for grades on a section by section basis. Each curve was checked for degree of curve and deflection angle. Each curve and each identi- fiable gradient section were then tabulated. The various segments * The Alaska Railroad has indicated that the current system load rating is E-50. susi4/j - 4 - ·. considered were cQmbined to' provide a total of thirty-three (33) possible alignment alter[latives that could conceivably be con- structed to provide access to one or both of the principle dam sites. The principle damsites were identified in the early stages of the study as Devils Canyon and Watana. The various com- bination of segments makir ~ Jp potential access routes were com- pared. The alignment identified as ·being the most attractive within each of the three (3) general corridors required by the plan of study was selected for further work. A low level recon- naissance fl.ight with part of the environmental team was made April 30, 1980 to review tbe proposed corridor alignments prior to the photographic flights. valuable input for future anlalysis was gained, and th~re was nothing identifed that would force a major line chaf\ge 9-t this early stage of the work. On May 15, 1980 the proposed corridor alignments were presented to representatives of Acres American. Photographic flights of the proposed corridors were approved at that meeting. E. ALTERNATIVES For the purpose of analysis the proposed general cor~ridors are identified as follows: Corridor 1 0 Corridor 2 0 Corridor 3 0 susi4/j On the north side of the Susitna River be- tween the Parks Highway and the Watana Dam site. On the south side of the Susitna River be- tween the Parks Highway and Watana Dam site. Connecting Watana Dam site with the Denali Highway to the north. - 5 - !· I r ---~---------------- A number of alternative segments were considered within each of these three (3) general corridors. The alternative segments within the respective corridors are discussed below and shown in Appendix A. 1. CORRIDOR 1 a. Alternative 1-A. This altl:.rnative begins at Watana Camp, Creek. and then proceeds north to a crossing of Tsusena After leaving Tsusena Creek the line proceeds through a pass at four-thousand foot ( 4000') elevation into the upper reaches of Devils Creek. As the line leaves Devils Creek it follows the side slope around just to the north of High Lake while gradually dropping in elevation and reaches the bluffs at Devils Canyon very near the Devils Canyon Dam s~te. From Devils Canyon Dam site the line traverses around ;nto the Portage Creek drainage and, after crossing Portage Creek parrallels a winter sled trail to a crossing of the Alaska Railroad at Chulitna Pass and on to the Parks Highway. This alternate crosses the highest ground at just over four- thousand foot (4000 1 ) elevation near the head of Devils Creek. Through various sections it also crosses some of the most difficult terrain of any route investigated, particularly in crossing Portage Creek. The entire section from just above Devils Canyon across Portage cr~eek and out to the vicinity of the cabins on the west side of Portage Creek is side hill construction in very steep and broken terrain. Preliminary grades are generally within criteria except for a few short sections. A preliminary check indicates that the grade problems should be solvable with minot ... adjustments of the i lne and some heavy earthwork. susi4/j - 6 - ·. Alternative 1-A has a number of curves that exceed the desired degree of c~rve parameter. As stated above this line traverses some very difficult terrain in the Devils Canyon through Portage Creek section. Because of this it may be difficult to eliminate all of the tight curve problems without a number of costly structures. b. Alternative 1-B is an alternate segment in Corridor 1 beginning at point 6 on sheet 6 and rejoining 1-A at point 4 on sheet 4 of Appendix A. This alter·nate segment utilizes a pass into Devils Creek immediatley south of the pass used by alternate 1-A. The pass utitized makes it possible to hold the high point of the line to just over three-thousand four- hundred foot (3400') elevation. As originally laid out 1-B has about two-thousand feet (2000 1 ) that exceed the six percent (6%) grade parameter. These areas can be eleminated dudng refinement of the alignment. There are a few curves on this alternate that exceed the five degr·ee (5°) parameter. These involve drainage crossings where changes in grade and some grading work will enable the designer to comply with approved guidelines. c. Alternate 1-C is a totally new line between Watana Dam site and alter·nate 1-B at Jts crossing of Devils Creek (See point 5 on sheet 4 of Appendix A). This alternate follows the river and would provide water level access to the reser- voir of Devils Canyon Dam. The preliminary layout includes several relatively short sec- tions that exceed the desired maximum grade.~ A few of these grade problems may be eleminated by refining the line, how- ever it may not be possible to eliminate all of the steeper sections. susi4/J - 7 - j l I I I I I I I I I I I I I I I I I I ,I Alternate 1-C includes at least three (3) curves that would be difficult and costly to flatten enough to ·comply with the desired criteria. Alternate 1-C is the longest of the three (3) lines between Watana and Devils Creek and woutd require at least three (3) bridgas .. d. Alternate 1-D is an alternative crossing of Portage Cr~.ek that uses switch backs and relatively steep grades ro shorten the stream crossing. (See point 2 on sheet 5 to point 3 on sheet 4 of Appendix A.) A thirty (30) mile per hour align- ment is possible but nothing better.. This aiternate is effectively eleminated for this reason. 2. CORRIDOR 2 a. Alternate 2-A begins at Watana Dam site on the south side of the river. The line proceeds southerly past the west end of Fog Lakes and across Fog Creek to the north end of Stephan Lake with good fine and gr.ade. The line cJ,imbs toward the high ground west of Stephan Lake at a comfortable grade to the top of the Chunilna Creek drainage. (See point 15 sheet 10 of Appendix A.) From there the road stays on the high ground at elevations of about three-thousand four- hundred feet (3400') to a point immediatley south of VABM CHUNJ LA (See sheet 8 of Appendix A) with good line and grade. From that point the line decends via steep grade and very tight switch backs to the Railroad at Sherman. Thh:: nne is approximately fiftv-six point six miles (56.6) in length. Grades for the most part are acceptable on the altermate 2-A with the exception of the climb from Sherman through the sus14/j -B - I I I I • I • I • • I I I I I I I I - switch backs. It will be difficult to improve signifcantly on that section. Another problem with 2-A that must be con- sidered is that a nine (9) mile plus spur must be constructed to serve Devils Canyon Dam. This spur is alternate 2-C and a part of 2-B. (See sheet 9 of Appendix A.) b. Alternate 2-B begins as 2-A ·flattens out after ·climbing out of the Stephan Lake basin. (See point 15 on sheet 10 of Appendix A). This segment travels northerly along the top edge of a deep narrow drainage for about six (6) miles (see point 13 sheet 10 Appendix A) where it turns westerly and crosses into and desends an unnamed drainage to Devils Canyon Dam site where it can connect with 2-1 . iv1uch of atternate 2-B exceeds acceptable grades and several curves exceed the acceptable degree of curve. This would be a thirty (30) mile per hour segment without question and the segment would include one (1) major bridge. c. Alternate 2-C is the segment that connects 2-A with 2-B about three (3) miles south of Devils Canyon. (See point 11 and 12 sheet 9 Appendix A.) The section is six (6) miles long and a major part exceeds grade criteria. The line has good hor·izontal aiignment but grades make this alternate very questionable. d. Alternate 2-D is a segment that connects 2-A at Sherman with the Parks Highway by a pass through the ridge on the west side of the Susitna River. The segment would require a major bridge and a crossing of the mainline railroad. This segment can completley satifsy desired criteria. (See sheet 7 of Appendix A.) susi4/j - 9 - f e. Alternate 2-E is a. segment that begins at Sherman and goes north essentially parrallaJ to the mainline railroad to connect with 1-A at Chulitna. This segment was addressed in order to provide alternative points of connection with the Parks Highway should some alternate within corridor 2 be ultimately selected. Only a portion of this segment would be used. A major river bridge may be required depending on what portion of the segment may be used. (Point 7 sheet 7 to point 1 sheet 2 of Appendix A.) The grades can be kept within desired limits with some heavy grading in two (2) short sections. The hoizontal alignment is within criteria. f. Alternate 2-F is a segment that would provide for a shorter roadway crossing of Fog Creek. The segment con- nects with 2-A on both ends and would require a high bridge approximately five-hundred fifty feet (550 1 ) long over Fog Creek. (Point 20 to 23 sheet 12 of Appendix A.) Grades are good throughout the segment. One (1) curve as shown is too tight. The curve could be brought into conformance by skewing the bridge across the creek and some grading work on the bridge approaches. g. Alternative 2-G is a segment intended to connect 2-B with 2-1 at Devils Canyon Dam site by essentially paralleling the railroad line 2-R-(Point 12 sheet 10 to point 10 sheet 9 of Appendix A.) 2-G begins about five-hundred feet (500 1 ) in elevation above 2-R then parallels the rail line 2-R at cl somewhat steeper gradient to connect with 2-1 at Devils Canyon Dam site. This segment is located in some difficult terrain. Some heavy cuts and fills wall be required and at least one (1) major bridge will be required across the side drainage just upstream from Devils Canyon Dam site. susi4/j .. 10 - J l I f r t I I ! ·. h. Alternate 2-H is a ·s~gment of roadway that goes up over a small bluff just upriver from the present railroad bridge at Goid Creek to avoid some difficult construction going around the face of the bluff. Both grade and alignment criteria can be satisfied. This segment is shown connecting with 2-E in two different ways. This is to indicate what might be required for connecting with Parks Highway using either 1-A or 2-D. L Alterna1:e 2-1 is a roadway following exactly on the railroad alignment 2-R from Devils Canyon Dam site to 2-H just above Gold Creek. (Point 10 sheet 9 to point 9 sheet 8 of Appendix A.) All design criter·ia ·for the roadway are satisfied. j. Alternate 2-R is the rail:--oad alignment between Gold Creek and Watana Dam site on the south side of the river. The rail line is within cr.;teria the entire length. The maximum curvature is about ~ight degrees (8°) and the ruling grade is a_bout two point three percent (2.3%). The most difficult terrain is fr·om Devils Canyon Dam to the Stephan Lake basin divide. One (1) major bridge will be required near Devils Canyon and one (1) or more minor bridges are likely. There is a six (6) mile section on one side of a north-south drainage that wil'l be full bench cut in rock and may require snow sheds to keep the tracks open in winter (see sheet 10). This line appears to be the only feasible possibility for rail access from Gold Creek to Wat:ana. 3. CORRIDOR 3 a. Alternate 3-A begins at Watana Dam si-t:e and proceeds north_east up the west side of Deadman Cr~ak then through a saddle into the upper Butte Creek drainage and along the susi4/j ... 11 - ·. . west shore of Butte Lake to the Denali Highway. This aiternate is the shortest connection to an existing highway. Only two (2) short S 1ections that exceed four percent C 4%) grade. The sharpest curve on the preliminary line is six degrees (6°). b. Alternate 3-B coincides with 3-A from Watana Dam site to the first crossing of Deadman Creek about five point five (5. 5) miles northf!ast of the dam site (see point 22 on sheet 13 of Appendix A). This alternate then proce1:ds easterly into the Watana Creek drainage and then northeasterly through a saddle into the lower end of Butte Cree,k drainage. The line traverses the west side of the Butte Creek valley passing Denali west of Snodgrass Highway near the Lake and connecting with the Susitna River B rio1ge. This alternate is slightly longer than 3-A and otherwist~ meets all design parameters. f. ANALYSIS With the various segments identified and estimates made ;Jf grades and curvature a total of thirty-three (33) combinations were de- veloped and compared. The criteria used to compare tl1e alter- native combinations are as follows: 0 ? 0 Overall length to be constructed; Average grade; Average de-Flection per mile. The tabulation of this comparsion is included in Appendix B. The alternatives identified as being most favorable based length, alignment and grade are as follows: susi4/J -12 - on ~--,--... - For Corridor 1. Parks HigHway to Watana Dam site -North side Use combination 2, Segments 1-A and 1-B Over a! I Length Average Grade Deflection Per Mile 64.9 Miles 2.4% 7°06'± This Corridor will be identified as Alternate A in further studies. For Corridor 2. Parks Highway to Watana Dam Site -South Side Use Combination 33, Segments 2-A; 2-F; 2-B; 2-G; 2-H; 2-E; 2-1 Overall Length Average Grade Deflection Per Mile 66.5 Miles 2.2% 4. 0 50°± This Corridor will be identified as Alternate B in further studies. For Corridor 3. Watana Dam to Denali Highway Use combination 10 -Segment 3-A Overall Length Average Grade Deflection Per Mile 39.1 Miles 1.3% 1 °30'± This Corridor wili be identified as Alternate C in fur·ther studies. For Railroad Use 2-R on th<a south side of the river from Gold Creek to Watana Dam site. This closely follows the preferred road alignment for Corridor 2. Overall Length Average Grade Deflection Per Mile 58 Miles 1.5% 5°11'± This line will be identified as Alternate R in further studies. susi4/j -13 - ·. G. RECOMM.ENDATION Based on the preceeding analysis it is recommended that Alternates A, B, C and R as detailed in section F be approved for further analysis. These alignments satisfy the established design creteria and the requirements of the plan of study. One of these align- ments or portions of more than one . will satisfy the forseeable concerns pertaining to project access. susi4/j -14 - -· '" / 1111 ·susi4/j ·. APPENDIX A PROPOSED CORRIDORS -14 - '' 1 j i I l I t I I . .. SUSQTNA ~ ~ ---· . . .. .. ... . . -~ . ... .. ... . ACCESS CCR~9DORS . \ . SUSBTNA CAM I ~ 'l 1 r l ! l J, i l I I' J !' I I l I I l I L ·. INDEX Corridor Guide Corridor 1 Corridor 2 Corridor 3 Recommended Road Way Alignment For Each Corridor susi4/j -16 - • Pages A -C Pages 1 - 6 Pages 7 -12 Pages 13 -20 • • t ! r l 1 t t i r l -----------------------~---------------~, ~J ! I I i r -, ' l I l I I I l 24 ·: 1 l I I j I l l I I I I ('" ! I I ! I I ' l .1 { l ! lc l l I l l I l I l ' I !' I l I 1 I l t l l l I I j I I ! I Continuation on page 7 I I 1 l I I ------~--------:..-------./~----....-----------~--------------·----~.l Continuation on paqe 8 ! I I l 1 c Continuation 0n nnaP q ·r l I l I l l I f r j l I ; ' l t I I l l I •t j .: l •t l 4 l I l ( c j. j j ! l I l ' Continuation on paqe 11 I - l t J ~ 1 l i j' l I 1 l l I ! I I I I ! I l I I I I \ l ' ;... \ J l l ' ' ("f l c l ~ I ... r c ~ { ~ l ( l + I r ,. l ... ~ l •r l l 1 I j I I l I l l l I I l l I Continuation on oaae 12 1 l ! Continuation 1. ! f I l l I l ! I l l ' l l ! ! I I I t l l I l l l I j I 0: ! l ! (L ! t It I f: l s: I c l s: l l c l ' ·.-l + l It l ... ,.. l s: •r 1-I ~ .. l ( I I l l \ j ' l 1 ) l \ f !I ,I r 1 i 1 \ l l 1 I ! i ' l ' I ( I l l ! l I 1 ! ( I nO• -' . l { l 7 ) l r l ---~ ·--------··~----~--- Continuation on page 3 r I l r l l ! / l 1 r· ! ~ c s: l ( I ( I \ ! r I I ! \ I l 1 l 9 I ~~~~==~F=~~~~~~~jl g r f." ,:: c !: c I l I ! I' I L, r- l !. [ I I I I Continutation on page 5 •t ( l l I I I I l l r I· I l I I I I I j I I I ! I [ l'' ! l ! I ; I I l f ! ·--· -----. 'il Continuation on page 17 13 .. l t l 1 I C~ntinuation on page 17 Continuation on page 18 l[ c t r c ~ ( ~ c .,.. -l- It $: .,.. + $: c L 61 a6Ed uo uo~~~nu~~uo~ I r t l (' ~ ~ I \ ..-· ii ~:..;.._-,-...:-..._.,_,_~-·-~:-.-...,.. .......... ~~ ... -;;___...,.........,_j~--... __,.j.., .... .:,,_,_,):,!.j,.j ~--'--~- Continuation on page 20 \ 1-., l 1 •. t. l J I I ' .. -,_,Is·· .....__. ... . . - I -·, " ..,: •:. ( J ' !' \ " ' · ..... .~,. .; ..) •'I i Continuation on page 13 Continuation on page 14 17 -& c ( .... \. I c. t }: i ( c ( .,... + ' I .. ... ~ ~ ,-\. ... 1 c \ ..... . r +-r s: c c.. .::-~ - l .l\ ,'i \ \ I' I != c c c .,.. -1- ct: ::::: c •ri .j..l c 0 u ··-~ ·2·" ..... _.., ______ -1 continuation on page 18 ~~. ' 19 ··~"" ~·1 } ; ! .. ' .,..,..-... _ ' !--'.-~---·· --. o·· t ~ ••.. ; ....l---, i l . .-:~.! ~~ -~"> ' . \....· .. 20 -.; ' -·-·· --· --·-·~ on page 15 . -' 19 i. ~ .. ,<"";--' ,-.. __ , .... ~ ··-·t--· -... _._._.. -... -.... -· , - II I : Continuation on page 16 : 2 l)) :_ --~ 20 ! .. ·~ ·. APPE£\ID!X B ALTERNATIVE COMPARISON susi4/j -40 - • Alternative 1-A Alternative 1-B Alternative 1-C Alternative 1-D Alternative 2-A Alternative 2-B Alternative 2-C Alternative 2-D Alternative 2-E Alternative .'2-F Alternative 2-G Alternative 2-H Alternative 2-1 Alternative 3-A Alternative 3-B Railroad (2R) Alternative 1-A - Curve 17 Three 41 A Alternative 1-A - Curve 1 Three 41A Alttenative 1-A - Curve 63 To Hwy. susi4/j Distance (Miles) 68.6 Miles 16.95 Miles 27.28 Miles 8. 77 Miles 56.6 Miles 11.91 Miles 6.04 Miles 10.55 Miles 15.73 Miles 4. 74 Miles 8.17 Miles 7. 64 Miles 12.13 Miles 39.09 Miles 41.98 Miles 58.0 Miles 20.67 Miles 27.80 Miles 30.18 Miles -41 - Average Grade 2.51% 1.91% 2.10% 4.19% 2.72% 3.32% 5.08% 3.32% 2.09% 2.09% 4.49% 1. 91% 1.13% 1.26% 1.15% 1.48% 2.43% 2.48% 2.64% 9, 0 Sum of Deflections 49Z 0 34.15' 57° 09. 92' 163° 36. 76' 125° 57.41 1 154° 29.53 1 79° 07.83 1 26° 15.781 16° 47. 84' 35° 15. 9'4 1 22° 15 .88' 152° 30.421 24° 00.90 1 18° 30.53 1 59° 15.721 93° 9.49 1 299° 58.86 1 89° 27' 111° 41.81 1 155°9. 85' r ·. North of Susitna River Access Roads (Corridors 1 and 3) Distance Average Defl. Sum cf (Miles) Grade Mile Deflection~. ~· '1 . Alternative 1-A - Wastana Camp to Parks Hwy. 68.6 Mi. 2.51% 70 10. 82' 492° 34.1:.• 2. Alternative 1-A, 1-B - Watana Camp to Parks Hwy. 64.8 Mi. 2.37% 7° 05.66 1 460° 17.0'7 1 3. Alternative 1-A, 1-C - Watana Camp to Parks Hwy. 68.08 Mi. 2.35% 7° 59.86' 544° 29.1 0' 4. Aiternative 1-A, 1-D Base Camp to Anch/Fbk. Hwy. 64.27 IVli. 2.70% 8° 29. 59' 545~0 5'1 ... 3' 5. Alternative 1-A, 1-8 1 1-D Watana Camp to Parks Hwy. 60.55 Mi. 2.58% 8° 28. 90' 513° 34 .. ')4' 6. Alternative 1-A, 1-C, 1-D Watana Camp to Parks Hwy. 63~ 75 Mi. 2.54% 9° 22.61 1 597° 46. )7 1 7. Alternative 1-A, 3·-A - Devils Canyon to Denali Hwy. 77.50 Mi. 1.83% S 0 07. 09' 396C' 39.52' 8. Alternative 1-A, 1-B, 3-A - Devils Canyon to Denali 73.79 Mi. 1.67% 4° S6.291 364° 22. 94' 9. Alternative 1-A 1 1-C 3-A -I Devils Canyon to Denali Hwy. 76.98 Mi. 2.22% S 0 49.63 1 448° 34. !l7 1 10. Alternative 3-A - Watana Camp to Denali Hwy. 39.09 Mi. 1.26% 1° 30. 96' S9° 1S.7~' 11. Alternative 3-B - Watana Camp to Denali Hwy. 41.98 Mi. 1.1S% 2° 13.1S' 93° 09.t')l 12. Alternative 1-A 1 3-B - Devils Canyon to Denali Hwy. 80.39 Mi. 1 .. 73% S 0 21.36 1 430° ?3 ··g• .., . - 13. Alternative 1-A, 1-B, 3-B - Devils Canyon to Denali Hwy. 76.68 Mi. 1.S8% 5° 11.641 398° 16.11 1 14. Alternative 1-A, 1-C 1 3-B - Devi Is Canyon to Denali Hwy. 79.86 Mi. 1.S9% 6° 02.49 1 482° 28.7 4' susi4/j -42 - South of Susitna River (Corridor 2) Distance Average Defl. Sum of (Miles) Grade Mile Deflections 15. Altern~tive 2-A -56.6 Mi. 2.72% 2° 43. 77' 154° 29. 53' Watana To Sherman 16. Alternative 2-A, 2-D - Watana To Parks Hwy. 67.15 Mi. 2-81% 2° 33. 05' 171° 17.371 17. Alternative 2-A 1 2-E - Watana To Parks Hwy. 76.51 Mi. 2.52% 2° 33.11 1 195° 14. 77' 18. Alternative 2-A 1 2-F - Watana To Sherman 54.79 Mi. 2.81% 3° 00.09 1 164° 26. 93' 19. Alternative 2-A 1 2-F I 2-D - Watana To Parks Hwy. 65.34 Mi. 2.89% 2° 46.43; 181° 14. 77' 20. Alternative 2-A, 2-F I 2-E - Watana To Gold Creek 74.69 Mi. 2.58% 2° 44.84 1 205° 12.17' 21. Alternative 2-A, 2-B 2-C -I Watana To Sherman 59.47 Mi. 3.26% 4° 02. 91' 240° 4S. 96' 22. Atlternative 2-A 1 2-F I 2-B, 2-C - Watana To Sherman 57.66 Mi. 3.36% 3° 57. 73' 228° 27.48 1 23. Altf3rnative 2-P., 2-B I 2-C 1 2-D - Watana To Parks Hwy. 70.02 Mi. 3.85% 3° 40.71; 257° 33.80' 24. Alternative 2-A, 2-F I 2-B, 2-C, 2-E - Watana To Parks Hwy. 77.56 Mi. 3.00% 3° 28.26 1 269° 12.721 25. Alternative 2-A, 2-B ( ?-G ,,., I 2-H - Watana To Gold Creek 51.66 Mi. 2.38% 5° 32.25' 286° 04.2 1 26. Alternative 2-A, 2-B I 2-G, 2-H I 2-D - Watcma To Parks Hwy. 68.50 Mi. 2.09% 4° 04.18 1 278° 46.48' susi4/j -43 - ·. South of Susitna River (Continued) susj4/j -44 - I ' ' I .. 1 l ,, t I l I I I a APPENDIX C I PERTiNENT CORRESPONDENCE ' I f \', I ~), susi4/j -4t\ - ENGINEERS GEOLOGISTS PLANNERS SURVEYORS April 15, 1980 Jim Gill Acres American, Inc. 2207 Spenard Road Anchorage, Alaska 99503 ... ... G·!.J .. :tl • :1) R&M No. 052210 .: • !'_ ..... . .. .. ~ . .. • .... , .. Re: Susitna Hydroelectric Project, Subtask 2.10, Access Road/Rail Road . - Dear Mr. Gill: : .. -. .. . ... Work has began on definition of the flight corr·idors for the s.ubject task. Early agreement on certain basic parameters is necessary. These parameters are maximum grades, minimum curve radius and/or degree of curve. The following values are proposed: Parameter Maximum Grade Maximum Degree of Curve Road (30 mph D2sign) . ±10% 19° These paramete1 .. s will be used unless instructions to the received. If ther·e are any questions, please contact this office. Sincerely, R&M CONSULTANTS, INC. Brent T. Drage, P.E. Susitna Project Coordinator BTD:NG/dj/SUSI 1-W ,, ~ .. -"",..._ Railroad ±2.5% 10° contrary are ... :_ . .. ·:-.. •.• !-:-.. -:: -'t •• ~ .. : .... '"::. '.::~ -:--:-. _·:~:·~··~,: ....... ........ ~· .!,-. · .. "-'"" .. ~· ~. . . - ·· .. . " ... ... .. ~· ...... T' . . . · . l i I r '\ l ·~ .~, ... . • ' • .: ~ ~ 4 ... : Mr. Brent Drage R~M Consultants~ Inc. 5024 Cordova Street P.O. Box 6087 Anchorage, AK 99503 Dear Brent: ·-. . May 1, 1980 P5700.11.10 T .131 Susitna Hydroelectric Project Access Road Requirements In reference to your letter of April 15, 1980 (R&M No. 052210) regarding ·access road parameters, we have the fo 11 0\-Ji ng comments. The road parame~ers proposed: a.) 30 mph ~esign b.) 10% max grade c.) 190 max curve are unacceptable. For several reasons, some of which are not completely defined, we recom- mend the following parameters. The design speed has not been exactly established; however, it will be 50 mph or 60 mph. a.) 50 mph design a.) 60 mph design b.) 7% max grade b.) 6% max grade c.) 7.60 max degree of curve c.) 5° max degree of curve The access road will be approximately 60 miles in length. It will be used during and after construction. Because of the 60 mile length, a 30 mph design would make an unseemingly long and boring ride. The use of the highway after construction has not been definitely established hov1ever, this l"Oad becoming a main highway in that region is very pos- sible. The above reasons are oversimply stated, however the 50 or 60 mph design will be studied more carefully and documented during the scheduled sub task. The railroad parameters stated: a.) 2.5% max grade b.) 100 max degree of curve are acceptable: It is envisioned at this time the rail line tc the site would be only a spur line and not a main line . . ~c;~ES AMERICAN l~ICC;:tPOnAT!::D ! f I t I ,... Mr. Brent Drage ~ R&M Consultants, Int: r.:~~.May 1 , 1980 ~:...~ Page 2 Probable wheel loadings for the access road are as follows. After con- struction AASHTO Standard HS 20 .. loadings and vehicles v1ill apply. During construction of tne project, the road will experience heavier loadings. The possibility of 200 ton transporters with maximum axle loads in the order of 80,000 lbs exists. These wheel loadings will be better defined during the scheduled sub task. As additional data and information is · obtained, it will be forwarded to you. If you have any questions, please feel free to contact this office. TWG/rm Acn;:s .4MEAICAN INCOriPORA T20 f • E .. ., -:: . .; _':' ()5~JD SUSITNA HYDROELECTRIC PROJECT Mr. John Lawrence Liberty Bank Building Main at Court ·. Buffalo, New York 14202 Dear John: ~ --.... ·~ Access Roads May 19, 1980 P5700.11.10 T00119A . - On Thursday, May 15, 1980, \s.Je met with Brent Drage, Bob Dortch and Norm Gutcher of R & M Consultants, to discuss the access ·road alignments. We are transmitting~ with this letter, one copy of the selected alignments to be flown this month as a result of those discussions. We are also transmitting a copy of a letter from Norm Gutcher outlining a number of questions which need to be answered relative to the access road study. With respect to·access road design criteria and the concerns raised by Chuck De bel ius in his memo of May 6, 1980, 'fie have discussed and resolved this matter to what we believe to be an acceptable criteria. The alignments chosen by R & M Consultants, as shown on the attached maps, are based on their original 30 mph criteria. However, most of the routes meet our more recent criteria of 50-60 mph. We believe this to be the best compromise and does not penalize-the economics of the road alignments by utilizing the 50-60 mph criteria throughout. One route not chosen for further study warrants specific comment. This route is on the south side of the river and goes straight over the top of the high country to the south. I~ was R ~ ;.i • s recommenda- tion that due to difficulty in keeping the grade down on the initial! section of the route as well as deep snow conditions over much of the alignment that this route not be pursued further. There are a numbe~ of options which can be further studied from a transportation economics point of view. These include extending the railway to Cant\•Jell and comparing the economics of the combined rai1/truck system for supply of construction materials. This could be compared to a southerly route of either truck only or a rail/ truck combination. These studies, of course, would only address the construction phase of the project and some consideration must also be given to the distance to the Watana site if the shortest access to the Denali Highway was utilized making the driving distance from Anchorage the longest. . The other option worth considering, which has merit from an environ- mental point of view, is to use the Denali Highway route to Watana ACRES AMERICAN INCORPORATED Cor.<Jul!lng E'1g1:1cers 2207 Spcnarct Road Anchotage, Alaska 93503 T~lephone 907 276·.!888 Telex 91-13~23 ACRES BUF John Lawrence -2 M~y 19, 1980 ·. and a rout~ north or south. of the river to the Devils Canyon site at some future date without connecting the two sites. -This in effect would restrict access to the area or would allow it, if desireable, connecting the two, providing general public access in a complete loop. One final note. Does FERC have an interest in the access road? There has been a suggestion that they will have it reviewed b~ FWHA. Please give the questions from R & M.your earliest consideration so that they can proceed with their work activities. Si ncere1y, (-/u~ /James D. ~il1 ( JDG/ja Resident Manager Enc: 2 cc: C. Debelius R & M Consultants ACRES AMERICAN INCORPORATED 1 J f I I l l ENGINEERS GEO\.OGISTS PI.ANNERS SURVEYORS May 12.r 1980 Acres American 2207 Spenard Anchorage, Alaska Attent.ion: .Jim Gill . Re; Task 2.10 -Access Road Dear Mr. Gill: • BOX. 6087 Ill ANCHORAGE. AL.ASKA 9950Z • PH. 907•279·0483 B TL.X.. 090•253&0 R&M No. 052210 Work on the subject tqsk has progressed to the point that three possible alignments will be ready for review during the week. of May 12, 1980. The three alignments to be reviewed are those which are to be flown and photo- graphed later this month. During the time work has been. underway a number of considerations have eome to mind that will have bearing on the transportation mode and route finally selected. The Susitna dam project will require a large scale continu- ous stream of suppiies. This supply effort will be a major item in the over-,- ali project cost. Listed below are a number of items that may effect the final selection of transportation mode and route. -Will both Watana and Devils Canyon dams be built at the same time? -If both dams are not buiit at the same time which dam will be built fir·st and what will be the anticipated time between construction of the two dams? -What is the anticipated length of time required for construction? ... What is the anticipated population of the construction camp? -What is the estimated rate of flow of supplies for the construction camp and crew. -Where will the camp and crew supplies come from? -What is the length of the annual construction season estimated to be? What will be the probable size and mix of the construction equip- ment fleet? ANCHORAGE: FAIHUANKS )UNE:AU VAt.OE::t WASIL.L.A r l [ I ( ! I -?WT ns May 12, 1980 Acres American Page -2- -~ ... (. __ ,. .. ·. -What is the estimated fuel requirements for the construction fleet and camp? ' What might be a reasonable rate of flow of spare parts for the construction equipment? -What type of construction· mater'iar·s will be required -and in what quantity? -Where will items such as fuel, cement, aggregate, steel and machine parts come from? -Is it reasonable to include the proposed rail line from Valdez to Fairbanks as a· possible supply corridor. This rail link has been discussed and. may be in the serious planning stages. If implemen- tation were to occur in timely fashion this may provide the shortest overland distance to the Watana Site from a deep water port facility. In addition to the above questions. pertaining to the long range project evaluation, we have a couple of questions, the answers to which, may impact our current scope of work and. time frame . . -Who is responsible for the economic and ·environmental analysis necessary to determine the most desirable transportation mode or modal mix and supply route, and how will they relate to R&M Consultants• technical analysis of the access .corridors? .. Will the location study h~ve to meet FHW A standards and, if so, which standards? It is realized that answer.s to all of these questions will not come immedi- ately. The .answers are, however, necessary input to the analysis and must be provided prior to preparation of the final location study raport. It is important that we know as soon as possible, what agency standards must be met and who is to conduct the economic analyses. 1 f you have any questions please let us know. Sincerely yours, R&Nl CONSULTANTS, INC. '"?. Z-.<A~ 7/ ~~- Norman K. Gutcher Senior Civil Engineer NKG/dj/L1-N C51.t s;::ri\\ 11 • • . _. • •. . • • . \ • --------~ ~~v~-----------------------------------~------------~·~·~·~·--·~·~-------~--------------- r I r I Mr. Brent Drage dJ::t) R&M Consul ta.nts, Inc .. 5024 Cordova Street P.O. Box 6086 Anchorage, Alaska 99503 Dear Brent: ·. June 6, 1980 P5700.11.10 T .189 () s 2. 000 Susitna Hydroelectric Project Access Road Requirements· I understand my letter of May 1 may have been misunderstood. This letter is to clarify the matter and inform you of Acres current requirements for access road route selection, pending more detailed studies at a later date. It is perhaps unfortunate that the stated speed requirements have been allowed to confuse the issue. Speed is not of concern at this time, since any required speed restrictions may eventually be imposed on a particular route. We are not in a position at this time to make a final judgement on such speed restrictions. It is more important, in fact essential, to insure that the road grades and bends are such as to allow transportation of the kinds of equipment we envisage for construction of the Susitna Project. You are therefore directed to insure that the selected access road routes for survey purposes will generally have a 6% maximum grade and a 5° maximum degree of curve .. Relaxation of these requirements to 7% and 7.6° respectively will be accepted locally if warranted for reasons of economy. vJe look for\·Jard to receiving your preliminary proposals for access road route selection for our r~view and approval. JDL/jmh . -•-: .. ~ . , • • f , . .; . Sin~erely, / ///;'Jr'VV"--~ L ~ohn 0. La\•Jrence Project fv1anager t / ! / !, I I r I . , .· ( . ...;. .. :·.~--·: ...... -· .! . -"' ••'-• ...... , .,. ~., .. ··-.. -... ~ ., " -"'. ••• I • \ ~ \ _..J .. • ."! •# -J ~-: 1 ~ - ·. R & M Consultants Incorporated 5024 Cordova Street Anchorage, Alaska 99503 Attention: Norman Gutcher Dear Norman: Access Roads August 13, 1980 \'=>5700.11.10 T00252A o522JO . We regret tpe long delay in_ answering your letter of May 12, 1980. The specific answers to your questions are as follows: 1. The Watana and Devil Canyon Dams will not be built at the same time. 2. ~~atana dam would.be bu.ilt first followed by the Devil-Canyon dam several years later .. .,. 3. Si nee ou1" own studies have not advanced far enough to make d~finite schedules our current best estimate of the construc- t~on period would be as outlined in the Corps of Engineers report, a copy of which is attached. You will note the rev·isions made to the schedule by the Corp in their 1979 report .. 4 -12. All of the information requested is not available at this time.. We do not believe that it is in fact needed at this stage.. It should be sufficient to know that the route must be capable of carrying large vehicles up to 60 ft .. length, with a gross weight of 200 tons (40 ton wheel loads) and that the route would be subjected to moderately high traffic volumes. 13. Since the proposed Valdez-Fairbanks rail line is only in the planning stages, it should not be assumed to be available. However, we should discuss it in the study report and state whether it would be worth considering as an alternative, should it materialize. 14. As outlined in the POS, TES are responsible for environmental aspects associated with the access route. We expect R&M to coordinate their input. v!e should be kept informed of \tJhat goes on and will certainly assist should RM1 have any problems. The objective of R&M's Subtask 2.10 activities are clear; i.e. to "define alternative access routes; evaluate technical, . " "" .. r L I I I l • .. .. (~ ~·~ . ' . Mr. Norman Gutcher - 2 August 13, 1980 . economic and en vi ronmenta 1 factor·s for each, and recommend the best alternative". He therefore expect R&N to under- take the necessary preliminary transportation cost studies in order to recommend a route. These cost studies could be based on average unit transportation and handling costs, and consideration of other aspects such as recreational access, reliability, land ownership, capability for handl- ing large pieces of equipment (e.g,, dimensions~ weight, etc .. ). R&t·1 should, however, do some sensitivity analyses, possibly including an·alternative rail/road configuration (to a lower level of detail) in the route selection report. 15. Acres will be providing R&M with details of FERC requirements and State permitting requirements •. We expect R&M to ensure that all permitting requirements and applicable rules and regulations are taken into account in this study. Sincerely, ~· ··-;; /) ·/· // James ~::::.....;.:-1"(':1~1 JDG/ja · Resident Manager Enc·l osures l 1 :t r ' . ' • f ; ~ I f t ' .j • 1 CONSTRUCTION SCHEDULE OMB COMMENT The 11-year construction schedule for the Watana project, based on preliminary inspection of comparable projects, ·appears to be on the short side •. A longer schedule of 14 years appears more reasonable becau~e of (1) normal slippages and (2) a 3-year peak con- struction schedule that calls for more work to be put in place on a single site than the Corps has ever accomplished in similar time periods. This should be reexamined and its effects on the project B/C ratio calculated. r.r ···-RAL ..o!..nC.. The construction schedule has been reanalyzed and lengthened'~rom 10 to 14 years. The Watana dam and powerp1ant will take 10 years to construct, an increase of 4 years over the previous schedulev The Devil Canyon project construction will require 8 years rather than the previously estimated 5 years. There will be 4 years of concurrent construction to meet power-on-line dates. DIVERSION PLANS The time for Watana diversion works constr~ction and stream diver- sian has been extended to 3 years from the previously estimated 2 years, ' because the construction access to the tunnel portals requires extensive rock cuts and added time. The start of construction of the diversion works for the Devil Canyon dam has been delayed frG 1 the 5th to the 7th year of Watana construction because it is dependent on stream regulation by the upstream Watana dam. 20 I l I I I ' f - t: n f MAIN DAMS Foundation preparation at Watana would be de1ayed to the 4th year as a result of the extended diversion requirements which would delay the start of cofferdam construction. Watana embankment construction, scheduled to begin in the 5th year ·and continue :nto the 10th;wou1d require 6 years instead of the previously estimated 3 years, based on construction seasons of 5 months with average daily placement rates of 80,000 cubic yards. Water impoundment would start' in the 8th year .. with power-on-line in October of the 10th year. The reservoir filling \'/ould continue beyond the power-on-line date and would depend on the ~ates of inflow and power generation. Foundation preparation for Devil Canyon dam would start in the 9th year, a 2 year delay from the earlier estimate. Concrete placement and dam completion would begin in the lOth year and require 5 years, an increase of 2 years over the earlier schedule. Impoundment would commence in the 13th year and end· ·with a full reservoir in October of the 14th year. EFFECT OF DELAY The presently scheduled power-on-line dates are 1994 for Watana and 1998 for Dev i1 .Canyon. These were previously scheduled for 1986 and 1990 respectively. These dates include the result of the changes in assumed congressional construction authorization from July 1980 to October 1984 and the revised construction schedule. Transmission line construction could be completed in 1991, permitting connection 21 ...... _ _.._....,. of the Anchorage and Fairbanks load centers in advance of Watana power- on-line. The economic evaluation is based on this longer 14-year con- struction schedule and the delayed power-on-line dates. Even with the longer 14-year construction period, additional con- struction delays are possible. The impacts, however, would be minimized by the recomrnended two-stage _construction sequence.. If s i gni fi cant delays were experienced on Watana, the start and schedule of Devil Canyon construction could ce adjusted with minimal cost impact. Delays in Devil Canyon construct~on would have no effect on Watana's schedule. The project•s economic justification has been analyzed to assess the impact of construction delays that would extend the power-on-line dates. As an example, a 2-year delay in Watana completion was evaluated. The primary effect on project cost would be the accumulation of addi- tional interest during construction. The 2-year delay increases average annual costs by about $17 million. The delay 0f Watana power-on-line would also affect project benefits, although the change would be small. The impact on benefits is due to the mix and schedule of thermal plants coming on line prior to Watana and to the rate of load growth during the years after power-on-line. For a 2-year delay, equivalent average annual power benefits \'/ould be reduced about $4 million. The net change in project economics would be an increase in total annual costs to $245 million and a reduction in annual benefits to $320 million. This decreases the benefit-cost ratio from 1.42 to 1.31. 22 .. .--I r· I I I ! I r I I i .. ... <· \. ·-.. .. ";ir"" Analys~s shows that the construction period would have to be prolonged at least an extra 9 years before the Susitna project would become uneconomic. 23 C.-. ---··-· •· ----.. _- ~ t, ·~ ., ~ .-_.·{ .:--.:;:1' ·. careful scheduling, planning, and the use of temporary, heated enclosures where construction situations would permit. f!.econstruction Planning for the Selected Plan: A period of abJut four years is estimated for preconstruct1on planning. The work scheduled fo~ this period includes an economic reanalysis, detailed environmental and' archaeological surveys~, topographic surveys, and explorations and foundation investigations for the Devil Canyon and Watana damsites. A 52-mile pioneer road from Gold·Creek to the Watana da~site would be constructed during preconstruction to allow heavy exploration equip- ment into the project area to facilitate the preconstruction investigations. Construction Schedule for the Selected Plan: G~neral: The construction period for the selected plan is esti- mated-to be 10 year·s., 6 years for Watarta Dam and pm11erplant, and 5 years for Devil Canyon Dam and powerplant. Construction period for trans- mission facilities is 3 years. Concurrent construction will be required to meet power-on-line schedules. The following paragraphs describe the sequence of construction for the selec~ed plan•s projects. Diversion Plans: Construction of the diversion works would start in the w1nter of the first year for Watana and the winter season of the fifth yea:--fo'r Devil Canyon. The diversion works could each be completed in two years. Main Dams: Site clearing and foundation preparation would start in the tl-11 rd year with materia 1 p 1 a cement s ched.ul ed from the fourth into the sixth year of construction for Watana Dam. The diversion tunnel would be closed in spring of the final construction year and Watana reservoir would fill to its normal full pool elevation by fall to supply power-on-line the following winter. Clearing and foundation preparation for Devil Canyon would start 1n the seventh year with material placement beginning in the eighth year and continuing into the tenth year of construction. The diversion tunnel would be closed in spring of the tenth year and the reservoir would be filled by fall of the tenth year_ Powerhouses: Construction of underground powerhouses would be concurrent wit~the main dams of both projects; and excavation and installation of mechanical and electrical equipment \'lould continue year- round. Four generating units would be installed in the Devil Canyon powerplant and three generating units in the Watana powerplanta Power- on-line (POL) for Watana is scheduled for 1986 and Devil Canyon POL is scheduled for 1990. · 94 PROJI whicl $11 'l tota· projl powe1 for · date i ntet date. perc~ cost the · cost~ normc es tir se 1 ec Sect l -.. -" . ~~~~~~~;.....::...:...;;;;...._........,. ~~~::.:.~ .. ::.~;::~·~;:.~; :_ :.~:,.:· ,. ·. \£ ... -:' --c ·----------·-·--·-.> ~,;< Vehicle access to the powerplant is provided by a service road across the top of the dam and an all-weather road on the right side of the river. The road will be 2.3 miles long including a 2,100-foot tunnel. The Devil Canyon switchyard is located on the left bank of the river immediately downstream of the rockfi11 section of the dam. The major portion of the lands within the reservoir area were withdrawn for power purposes in 1958. The Devil Canyon Dam powersite withdrawal includes all lands below the 1,500-foot contour elevation. Devil Canyon reservoir would have· a surface area of 7,550 acres at normal full pool elevation of 1,450 feet. The minimum power pool level would be at elevation 1,275, while the maximum elevation produced by the design flood would be 1~455 feet. The reservoir would extend about 28 miles upstream to about 2 miles below the Watana damsite. The _ reservoir area, confined within the Susitna River canyon, is narrow. · Devil Canyon damsite will be 27 road miles fr~m the Parks Highway and 37 road miles from Watana. Tentative sites have been selected for temporary construction camps as well as for permanent facilities for operating personnel. The temporary construction camps will consist of units reused from the construction of Watana Dam. For study purposes the reservoirs were operated to provide optimum . power operation during the average year. To maintain maximum powerhead, Devil Canyon was given priority by providing storage releases from Watana as necessary. Watana was operated to maintain the Devil Canyon maximum pool and to provide additional capacity and energy. · During the first five years of operationt prior to the completion of the Devil Canyon project, Watana would be operated to provide capa- city and generation as demanded to the limits of its capability. Full ol conditions would usually occur during the summer months of July through October (the most severe historic floods have usually occurred uring the spring sno~~elt of May and June). Devil Canyon reservoir is expected ta remain full almost 100 percent of the time. NSTRU~TION SCHEDULE nstruction Season: The outdoor construction season at Devil Canyon nd tana ams tes is about six months and could be extended by 93 11 . . • l ~ ; i