Loading...
HomeMy WebLinkAboutAPA3070ltant , Under ract to za co Susitna 'lenture p ity iscuss 5 ss E L N.3 N.5 r p Ek t a e a s I ant er Summa er Summa er Summa er Summa er Summa E er Summa r, E a er Summa r, Ekl a er Summa E a er Summa E a er Summa E a er Summa 8 Ekl a er Summa f 1 E I a er Summa -June, 1 er Summa -JUly 1 1 er Summa ugu er Summa e Su er Summa b s -Glacier rk b s -er rk Sus u s 1 u ze u vs. me-a 9 5- -1 re - n h Su iment e-Size u -'1 ilrace 1 a ream-s id 1 ream-s us s p er P er P 1 er P 1 a er a er P E a Weather P -January, 1 er Plot -Februa er Plot -rch, er P . 1 E er P 1 1 . 1 E a er P -June, 1 a er P -July 1 1 a ugu a er P a er P 1 a er P p n r n re P re P re P le, 17, u kl Project il race, u re 2 ra sm;ss ra p s s re for Inland collection since 1982 was pe B Jo a Bill h compilation. Jeff Co·ffin was res sib e a ts e p n I author of 1s rs re Ul processes Ul e lake (1. have similar rated or ope r h ling w as Eklutna Lake, continuous rature, outflow volume and nsferred to and from erma I account 1n the !a 1n les and e Ia e XIng environ and e same me reams and n 1n June 1 an u h were u re, a d on an cs. 1 esig re also e k , a rneasu s a on neous values we ve humidity, s Cumulative same intervals. wind gu observed over za ar p e repo Data were recorded on once per month during ins were he cas were comp proces and summa sis a ist. a the lake one po1n p ma t r1es combine rm ream. r·eam was and s e lack s access a ne a es from Ekl Gl2cier rk; er was call reco ea en . a s y n i I I, n Ia con a 1 a ill ang from a d same occa was ng a brass , ~a r·n 1 s were id con cent ical and G s li re vvas were ai q a u d u res ran from a h oo e 1ce r res ranged 3 and 13° , rema covered season. The Ia r: 1n after breakup and in ral in nces were noted where re or 1n the center of the Ia ( 9) could ced I rearn p e Ia ex r, more tu id pi ume 1 n the Ia ke was va tng d was occas erally a as , ding on seen as an unde as r ( -Ia 9, n t concent reams, from 0.1 tempe re (on the ) , and coul ree miles. a s ran from 0.1 e Ia n va ues in occu ( a b r ( ginal vers Prior a model 1s ng calibrated using 1 e na ( Fig u re 2 . 1 ) . e d Eklu 1 in e li e Ia coli 1n u as e . 1 . lacial u 1 e E a e a ' en vi t s m1x1nf1 1n in h s ent an y s rom e N (N. \IV ere and have ) . a ni e unici Ia t n . i I , c rences " a summa p at e , Ia e ou s ver and r , Sections 3 ke systems are discuss 1n S nature are presented in e how r1ver and lake rameters main va other. he a dices, Volume 2, were used p re these p available are also in u 1n e a h p es \ivhich dices. re proces L g-c from les and graphs on a !y SIS. p of e s1 in Fig and 3.2. sensor con g u s are s e R !np t were vai able from e he nea fi -o , was us Ekl na L . .;., ..;~,-, re. pressure was u was from n va it a u s cove es d f e n SENSOR ARRAY HOUSING MOMETER AND WIND VANE FORMS ARE 10m ± APART. CLEARING FillED WITH SMAll BRUSH (1-2m ). BY LARGER TREES. CLEA lNG 20-30 m WI w I k . ' '. :. l { I ! ! 3 . 1 E ke s 3. 2 Eklutna La Cl site, looking SE towa uppe in. pa Ekl 1ns an wind vane, a shi and RH sensors. 3.4 Auxiliary sensor pi Ekl Cl sors inclu (I are ar sensor, ve sensor, a tipping buc p were establ level recorders charts were to stream were gage on Uing Is were in in ) were ca a cu meters per ( ) use . . . 2 mon nuou on press a 1 to nea 0. were mc~asu model 5-C-T ( Sediment). 1:.'. s Ju and August 1 ana n case, re was measu Amt~~.r~•· re, the measured cond v was (APHA et al. 1981). a U.S. (U.S.G.S, s one ( ruhn s s ana na 1 until Augu 1 rchased and used turbidity (i.e., 90° for the measure of nt~phelometric ( et al. 1981). Calibration sta rds were su instrument manufacturers. Some differences were measurements made the two instruments, so p imina val adjusted using an empi rica I correction relationship. ly discha and re 1 for ir 1 are shown in F ures a 4.4, insta neous in mean dai ratu res, a also p insta s values and su ( ) . stream ins 9 ( s squ d k's square mi T is in e Eklutna G te nus T accompan h. warm res, and turbidity data col in comparison with the streamflow and ratu re and .4. High-turbidity and high- generally coinciding with rises in the di on the discharge plots, however, rbidity plots, and vice versa. There are two reasons data are plotted for every day, while re available only from the times sampled, i.e. (Q) could rise and II s levels would also pres in this pattern was infl 4.4 in re in ur::e g rent is ntaneous values. rm sunny per week. risen an-:1 ships i value tinuous reco pa si is were u use in X N .6. and turbidity was s are shown in Figures 4.7 and ression equations. A turbidity values in measurements. It should be noted that the for each stream, so application of specific and are flowing water only (i.e. streams arise from differences in , shape, density, and color. art: p in ure 4. 9 a were meters) at ree curvE~s lues a q u size, . 10 ree sunshine. sun. However, in very flat hydrograph contrast, the a 4. fi several " sun in the late afternoon or evening a TSS, turbidity, a r to that of the streamflows. water re 0 00 4 0 E Ul ,_. ,.....,. rn E ~ U1 U1 t-+ + + I S ( f ,...... t-z .,__, >-..... H t::l H CQ 0: t- 30 20 99.9 99 90 50 10 1.0 0.1 FINER Y OLU TE S ZE :I Cl) Cl) 1- soo 250 :wo 2.0 1.0 0.0 2000 2200 JULY I\ 1 D 19 I' 5. 1.2 ss u a ity were me as u a itor. A probe was digital A mercu measu Sp (YSI) Model 33 S-C-T measu re 0 to 2 m, a in some cases from 0-14 m to rtek 1ng . was also measu on samp ta and tu analyses. to making measurements ai: res were to nearest 0.1 and condu v in uous st ng s spen per n rom a The at (APHA et a . 1 ) . raphs fix at di 9 (Figure 3.1) = " .5 From (present u I A u 1 were ana tu were B) * Z) (5 ) in ) tu was mea.;u from s (AP ) . These R USI imeter, normal u 5. 1.6 s 1,. 1 es r total su same p usive, was pe a ures pump, IS pe ids S) concentration we as u r tu idi Augu 16 and retaining one-liter measur·1ng tu were r! 9 a Station 9 in plot ax on the point in Ia or on location an for hydroelectric power in a northern in and October (after e summer high and in June (following ) . The observed annual fl was 12 meters ( 40 feet), maximum at II p le are presented in ix G. p the Ia temper·atu re for sampli trips with r or more s are in A ix H. Eklutna ex hi bits h rn periods annually, ns C around or ea each year -ile 1n e spring. Ia s to maximum Ice formation can 5 rmal si at C i n as s con as a s m a I in event sea compa son. rrences response: cons ing in 1 ng xi s winds wi , on res 5.4-5.6. was II a in res di e were a! a d were prep a same con n from n n s a e the high con (1 or ly time, a water at ing u as I. ures in cs su summer season-one -1 u m ) use 9. ax s reases direct s i values. or k h s ex shi a cou in E utna is some scatter in n is one -f s v ver·sa. I di F 5.17 s values values. qu a bit of ( idation :::hip come from in e in sediment cha a er :::-li ar·e inc I in several ix G contains ual ing trips, a sheet on s are p J. res H .1-H. e r~e each sampli we at mo s. gures J. 1 a J.2 p a S, a u u ai 5 Ia during five- . 1-.9 provi summa ~..---1-------") ~o..,~--o--6 ------- NOTE: TEMPERATURES IN DEGREES CELS US. ? MAY \ 10 5 I I I \ I I I \ I 0.0 -2.0 ...... ... ,-.., + + +-> 4-+ ""-/' + + + -4.0 1-+ w 1--t -·6. 0 <~ u + u + w + U1 ++ -8.0 -10.0 (S) (S) EXTI H H - EX I .0 >-10.0 1-- H > H U1 9.0 U1 ._I (f) + cr: 8.0 1-- 1--z 7.0 w u {}:: * w + CL + 6.0 5.0 ~----------~------------~----------~------------~---------~ tSl ru EXT NCT 0.0 + + -2.0 + 1· .,-... +> + .t + 4-+ .,_, 4.0 t 1- (L w + r.::l H 6.0 u u w T ( >- H I-I measu ) ilrace Hyd ka re and discharge three times daily, at 1 ant ni sensed temperature in a pen flow passing rough each tu ne was calcu from production performance curves. Ia Administration in ac per a d per a rs inp 1 tai r·ace were es were s, e norma s n in rical correction ship. R&M for conductivity usi a T a adjusted to conductivity at 25°C (AP ) . of sediment concentration were I a Alas Inc. using n total nonfiltel"able ue (A A et 1 were refrige after u I anal is, was normal same as or sampli 0. cron pore sizes were used s s. size distributions an min era ic anal es, El h rst . . 7 ri s ) . was u n res were nea 0. ly s, as defined (1 , were measu in a submerged. 0.1 foot . quadrants and Secchi disk measu were layout of the Eklutna Hydroelectric Project works, incl ing nt intake in the lake and the tailrace adjacent are shown schematically in Figure 6. 1. The i are withdrawal at a single level in the reservoir (elevation 794 are located on the north shore of Eklutna Lake near 15 (Figure 3.1). original intake structure extended over 200 along s ea con lake bottom and was surrounded by gently-s sides, as shown in Figure 6. 1. However, c intake had be rehabil s an uncontrol has di arou 1 one-half only ( 10: (1 ) sinc.c n 1 I 1 ... J. was con a p s. It is now u.s. a d r, with a design flow steel pipe encased in 75" in different portions of instal capacity of the two Francis-type powerplant is 33,334 kilowatts, with a max1mum gross Average annual energy production from the plant and 1980 was 156,000 megawatt-hours, ranging from 97,000 megawatt-hours in any year. The tailrace consists reinforced-concrete pressure conduit, 209 feet long a of ng width and depth, which discharges into an open chan T channel has a 25-foot bottom width, side slopes of 2:1, a 12.5 feet, and a length about 2000 before Kni k River (CH2fv1 Hill 1981). 6 .. 2 and e va of TSS, tu , Secchi disk ' a in re s s value duri open in ure 6. 2. was r season. The is re ri ra 3. C in a high a s measured in were r, with a few upwa spikes, li Ia The base level of turbidity also rose duri summer season. Turbidity over the NTU in ea June to a peak of 46 NTU in k down to 6. 6 NTU by November before the Ia values varied from a spring low of 0. 5 mg/1 in June a h in late July and then a low again of 2.2 mg/1 in November. n fluctuations, between 2.2 and 7.6 mg/1 and 6.6 and 15.5 , we for TSS and turbidity after mid-September. k in both plots in late August was probably aue rong wou ilrace presence n nds that blev/ down the lake and persisted for several would tend nsport more surface water to move more of the turbid inflow re also rose slightly at is time, p due warm surface water in e increases 1n tu d and s is ng e waves (up to 2 5 s. a T to e r at T are in u F, F. F. , RESM model are ues of outflow volume, utna of which were il race. re Project (from the U.S. G. S. for the recent Ia in s). Water Project (EWP), a project to transport drin Lake to Anchorage, is currently being developed E of Anchorage Water and Wastewater Utility. The engineeri Munici lity prepared a report ich presented some -acquired water quality and sediment data (Montgomery ineers, 1984). These data and supporting information are u in x in Tables .1 and M.2, Figures M.l .6, and P M.l a were collected at the powerplant during ree six-wee hases in 1983: February-March, May-June, and 4.1 g ranges of numerous water qual pa duri their Plots of turbidity a are s in ure were obtai ra va rua th F 7.5 a October 1 F (13°C), a NTU. size were re re~s val di p pa n 7 IN RU INTAKE RUC R NCRETE LINEOTUNNEL2 ER NE E S FT H H 1- 20 10 8 7 6 5 4 3 2 1 + in in res 7 . 1 -. 3, r way follow cons together. min tu occu in early June, rose sha a observed peak of the year around July 1. a a bit but stayed high for almost all Ju tu 9 occurred in ea June rose gradually through June a not peak until mid-July, a or two after streams' pea is expected, considering travel time down Ia rences ing frequency could also effect e apparent d in events. A further lag was seen at the tai I race: the rise in tu n in late June and continued until the peak in Ju ry rises in rbidity on both streams in late July s up as h values 9 about 2 and a week or so (late A u There were also some August e id e -1 con as can 9 wa h a was to res res, a simi a couple !"8S were TSS/tu rbidity samples were rd conditions at the lake su seen comparing Figure 5.3. s grou stream very en vi quirk;y in a in but occu summer so in is vvas was re flu -air n June, e d, 1 13 23,500 27,100 7 93 100 Inflow data were 1, 0 0 0 0 10,000 30,900 38,600 94,800 measured by 1 500 3 400 400 65 700 15 187,900 R&M Values were estimated, values \vere partially estimated .. 206, Outflow data were provided by Alaska Power Administration D y 5, J. 1981. A :5. In: Transport s a .B. . ) . Proceedings of a urn on p Press, Inc. 1 p aspects s Laboratories, Ltd. Elmhu , Illinois. neers,. Inc. 1 k 7, E utna Prepa nicipal A a ni (N .. A.A.). a annual umma ce, al Cl il 1 ina.