1// ~(cg'( DWORSBAK

NORTHFORK ,

CORPS OF ENGINEERS --• Access Road Plans Construction facts fish facilities Logging 0perations

DWORSHAK DAM WILL BE A STRAIGHT GRAVITY DAM, WITH COMPLETION OF , THE 53- MILE­ 693 FEET IN HEIGHT FROM BEDROCK BASE TO CREST, WITH LONG RESERVOIR WILL BE USED TO TRANSPORT DOWN­ A CREST LENGTH OF 3,300 FEET. THE DAM BASE WIDTH Will STREAM, LOG BOOMS FROM THE TIMBER OPERATIONS BE 525 FEET, WITH A CREST DECK WIDTH OF 30 FEET, PRO­ FURTHER UP RIVER. A LOG-HANDLING RAMP WITH UN­ VIDING TWO TRAFFIC lANES ACROSS THE DAM. LOADING FACILITIES TO BE SERVICED BY AN 800-FOOT BY THE SPILLWAY AND OUTLET WORKS, WHICH WILL RE­ 300-FOOT DECKING AREA NEAR THE SOUTH SHORE OF THE LEASE THE WATER FROM THE RESERVOIR BEHIND THE DAM, DAM FOREBAY, IS BEING PLANNED. WILL BE EMBEDDED IN THE DAM STRUCTURE. CONTROL WILL LOGS WILL BE HANDLED THROUGH THE USE OF A RAIL BE BY 9-FOOT BY 12.5-FOOT TAINTER VALVES. APPROXI­ RAMP CAR WHICH WILL DESCEND DEEP INTO THE POOL i.OG DECKING SITE DOWNSTREAM MATELY 7 MILLION CUBIC YARDS OF CONCRETE Will BE WATER. THE RAIL RAMP CAR, OPERATING BY CABLE, ON FROM DENT REQUIRED TO COMPLETE THE DWORSHAK PROJECT. A ROCK BEING PULLED UP THE RAMP WILL PICK UP THE BOUND FULL USE WILL BE MADE OF EXISTING COUNTY ROADS QUARRY WILL BE ESTABLISHED NEAR THE DAMSITE AND THE BUNDLES OF LOGS FLOATING DOWN-RESERVOIR, AND IN PROVIDING SUITABLE APPROACHES TO THE DWORSHAK AGGREGATE NECESSARY TO THE STRUCTURE Will BE SE­ LIFT THEM OUT OF THE WATER TO HIGHER GROUND AT THE RESERVOIR, THROUGH CONSTRUCTION OF BRIDGES AND CURED BY THE CRUSHING OF QUARRY ROCK. DECK AREA. HERE IT WILL BE POSSIBLE FOR VARIOUS OPER­ NEW INTERSECTING ROUTES. THE PRESENT ACCESS ROAD CON FL UEN CE O F CLEARWATER AND DURING THE PROCESS OF SETTING AND HARDENING ATORS TO IDENTIFY THEIR LOGS. LEADING UPSTREAM FROM AHSAHKA WILL BE UTILIZED N. FOR K CLEARWATER OF THE CEMENT MIX INTO CONCRETE, A CHEMICAL ACTION THE LOG BUNDLES WILL THEN BE LOADED UPON HIGH­ TO PROVIDE ACCESS TO A RECREATION AREA JUST ABOVE THE NORTH FORK OF THE CLEARWATER RIVER SUPPORTS OCCURS WHICH PRODUCES CONSIDERABLE HEATING. TO WAY TRUCKS TO BE MOVED TO DOWNSTREAM MILLS OR DWORSHAK, TO BE KNOWN AS THE BIG EDDY SITE. A SIZEABLE RUN OF STEELHEAD TROUT. FEW CHINOOK ASSURE REGULATION OF TEMPERATURE IN All CONCRETE TRANSPORTED TO OTHER AVAILABLE MILL SITES. THE RAIL THE ACCESS REPLACEMENT ROAD TO CLEARVIEW AND SALMON INHABIT THE WATERSHED. THESE RUNS Will BE STAGES, MILES OF l-INCH PIPE WILL BE EMBEDDED IN THE RAMP CAR FACILITIES WILL OPERATE ABOUT 10 MONTHS OUT ADJOINING RECREAT IONAL AREAS, INCLUDING DENT, MAINTAINED DURING THE CONSTRUCTION PERIOD BY DAM TO SUPPLY THE COOLING WATER NECESSARY DURING OF THE YEAR AND, IF NEEDED, ON A DOUBLE-SHIFT BASIS. WILL BE THROUGH USE OF EXISTING COUNTY ROAD LEAD­ TEMPORARY PASSAGE FACILITIES THAT Will PERMIT ADULT THE CURING STAGE. ING NORTH FROM OROFINO AND CROSSING THE RESERVOIR FISH TO UTILIZE THEIR NATURAL SPAWNING AREAS. FOR JUST SOUTH OF DENT. TH IS BRIDGE CROSSING WILL BE A APPROXIMATELY 6 MONTHS OF EACH YEAR, DURING LOW 1, 980-FOOT SPAN SOME 500 FEET HIGH, AND WILL CON­ RIVER FLOWS THESE FISH Will SWIM THROUGH THE DIVER­ NECT ON THE NORTH SHORE WITH THE PRESENT EXISTING SION TUNNEL. DURING HIGHER FLOW PERIODS, THE FISH COUNTY ROAD LEADING NORTH TO ELK RIVER. WILL BE TRAPPED AT THE MOUTH OF THE DIVERSION TUNNEL THE RESERVOIR BRIDGE AT DENT WILL BE A $5.6 MILLION AND TRUCKED AROUND THE CONSTRUCTION AREA. STRUCTURE. THE BRIDGE WILL PROVIDE THE SHORTEST POS­ JWENILE, SEAWARD MIGRANT FISH WILL PASS THROUGH SIBLE ROUTE TO ELK RIVER, AND WILL TIE THE TIMBER RE­ THE DIVERSION TUNNEL. SOURCES OF THE COUNTY TOGETHER. A LARGE ARTIFICIAL PROPAGATION STATION LOCATED TENTATIVE PLANS ARE FOR ANOTHER RESERVOIR SEVERAL MILES DOWNSTREAM FROM THE PROJECT IS PRE­ BRIDGE CROSSING UPSTREAM, JUST BELOW THE BRANCH OF SENTLY PLANNED AS A PERMANENT METHOD OF MAINTAIN­ THE LITTLE NORTH FORK OF THE CLEARWATER. THIS CROSS­ ING NORTH FORK STEELHEAD POPULATIONS. TRANSFER OF ING WOULD BE ACCESSIBLE FROM OROFINO VIA HEAD­ THE STEELHEAD RUN TO THIS HATCHERY WILL BE CLOSELY QUARTERS, AND WOULD CONNECT WITH THE PRESENT TIMED WITH RESERVOIR FILLING AND FLOODING OF NATU­ TIMBER CLEARING GETS UN DERWAY COUNTY ROAD LEADING WEST TO ELK RIVER. RAL SPAWNING AREAS. WORK AREA AT DWORSHAK TUNNEL NEAR DAM SITE Scnetn(Jfic /tf(Jp Pr()J'ect Sf(Jfistics 1// ~(% '1 THIS MAP SHOWS THE SERIES OF COLUMBIA BASIN MULTI­ PURPOSE PROJECTS, INCLUDING THE THREE CANADIAN TREATY DWORSBAK. STORAGE . GENERAL Drainage oreo (square miles). 2,440 DAM Annual runoff, minimum (acre-feet) 2,157,000 Annual runoff, mean (acre-feet) . 4,082,000 ~~ BRUCES EDDY" Annual runoff, maximum (acre-feet) . 6,680,000 River flow, minimum (c.f.s.). 250 River flow, mean (c.f.s.) •• 5,638 ARTIST'S CONCEPTION OF DWORSHAK DAM NORTHFORK River flow, maximum (c.f.s.) 100,000 DWORSHAK DAM AND RESERVOIR REPRESENTS A MOST CLEARWATER IMPORTANT UNIT IN THE CORPS OF ENGINEERS' COMPRE­ RESERVOIR HENSIVE PROGRAM FOR THE FULL DEVELOPMENT OF THE Nomoi pool elevation (m. s .I.). 1,600 RIVER, IDAHO WATER RESOURCES OF THE COLUMBIA- DRAIN­ Minimum pool elevation (m.s.l.) 1,445 AGE AREA. THE NORTH FORK OF THE CLEARWATER IS A Gross Capacity (acre-feet) 3,453,000 MAJOR FLOOD PRODUCING STREAM. THE DWORSHAK PRO­ Usable capacity (acre-feet) 2,000,000 JECT WILL SERVE TO REGULATE THE CLEARWATER RIVER FLOW Length of reservoir (miles) 53 FROM AHSAHKA TO ITS CONFLUENCE WITH THE SNAKE AT Shore line (miles). • • • 183 LEWISTON. Pool area ot elevation 1 ,600 (m.s.l.) (acres) 17,000 DWORSHAK RESERVOIR WILL HAVE A MAXIMUM POOL Pool area at elevation 1,445 (m.s.l.) (acres) 9,000 ELEVATION OF 1,600 FEET ABOVE SEA LEVEL AND A MINI MUM OF 1,445 FEET. THE DWORSHAK RESERVOIR, AT MAX­ DAM IMUM POOL, WILL EXTEND 53 MILES UPSTREAM AND COVER Height of dam, foundation to crest (feet) 693 AN AREA OF 17,000 ACRES. THE WATER STORAGE CAPACITY Length of crest (feet) . 3,300 OF THE RESERVOIR WILL BE 3,500,000 ACRE-FEET OF WHICH Power Generation 2 MILLION ACRE-FEET WILL BE USABLE FOR FLOOD CONTROL 3 Initial units, KW 400,000 \ ,r$-~~ AND POWER PURPOSES. THIS 2 MILLION ACRE- FEET OF 6 Ultimate units, KW 1,060,000 I -· \~ USABLE RESERVOIR WATER WILL NECESSITATE SEASONAL Concrete, approximate (cubic yards). 6,000,000 U. 5. ARMY DRAWDOWN OF 155 FEET FROM MAXIMUM TO MINIMUM Construction time (yean) 7 POOL LEVEL. ENGINEER Power-on- line, estimate 1972 IN ITS OPERATIONAL PLAN, THE DRAWDOWN OF THE Cost, approximate . . . $210 Million DISTRICT, DWORSHAK RESERVOIR FROM MAX IMUM TO MINIMUM ELE ­ VATION WILL BE DURING THE LATE FALL AND WINTER SEA­ WALLA WALLA SON WHEN DOWNSTREAM RIVER FLOWS ARE AT A MINIMUM. DURING THE SPR ING AND SUMMER RECREATIONAL SEASON, THE RESERVO IR LEVELS WILL BE REPLENISHED AND, AS FAR AS POSSIBLE, HELD TO NEAR THE MAXIMUM LEVELS. -- r-- 1

~~==~~~O~ANE \

HEAVILY TIMBERED SLOPES OF THE NORTH FORK CLEARWATER RIVER, IDAHO

OREGON

VICINITY MAP

SCALE IN MILES so 0 50 100 ----~~;,-..~

NORTH FORK CLEARWATER DOWNSTREAM FROM DENT ABANDONED LOGGING CAMP NEAR BIG BEND CORNER

LEGEND

~ POTENTIAL RECREATION AREAS m ·; :;t MINIMUM POOL I I MAXIMUM POOL PRIMARY ROADS

SECONDARY ROADS

••••• ROAD TO BE INUNDATED

RELOCATION

DWORSHAK RESERVOIR

NORTH FORK CLEARWATER RIVER IDAHO U. S. ARMY CORPS OF ENGINEERS

1965

OLD HOMESTEAD AT FOOT OF DENT GRADE