The Bear River has been described by many officials in the state of Utah as the last tapped water source for the state of Utah.  Figure 1 shows the state of Utah and the counties in Utah where the two reservoirs are to built.  Box Elder county is located to the east of Cache county, with Weber county just south of where the bear river enters the Great Salt Lake.  Figure 2 (click here to open figure) shows the relative location of the two reservoirs to be built in the state of Utah, being the Barrens and Honeyville reservoirs.  The headwaters of the Bear River rise in the state of Utah in the high Uintah mountains, travel north into the state of Wyoming and then back in to Utah, crossing out of Utah back into Wyoming still traveling north and then into Idaho.  At Soda Springs Idaho the river turns south and heads back down into Utah.  Cutler dam controls the bear river near Newton, Utah, and releases the river flow down to where it combines with the Malad river and then continues down into the Great Salt Lake.

   
    Severe flooding in the state of Utah during the early 1980's induced serious talks on flood protection in the state.  Figure 3 shows the severe flooding in downtown Salt lake City.  The flooding in the picture was a result from City Creek flooding in downtown and did not rise from flooding in the bear river, but the figure shows the state of many cities across the wasatch front that had to deal with severe flooding.  From then until 1991 several possible paths of action were discussed and the resulting analysis suggested two new reservoirs as part of the 1991 Bear River Development Act.  The two reservoirs being considered today, as put forth in 1991, are the Honeyville and Barrens dams in northern Utah.  A smaller version of the Honeyville dam is also being considered which has been called the Beeton dam.   Figure 4 shows the relative location of the two reservoirs in the northern Utah region.  

    A - Area Dangers

        i.  Barrens Reservoir
            The Barrens dam seems an isolated reservoir overtaking land which farmers have not used for several decades due to high salinity in the soil and overall not suitable for farming.  The reservoir is located just south of Newton and to the west of Amalga, Utah.  Southern  Trenton houses several farms, none of which would be severely overrun with the reservoir in place.  Amalga houses several cheese plants, most notably Cache Valley Cheese, which lie no more than 200 meters to the east of the reservoir.  A dam break in the eastern direction would be disastrous to the cheese industry in Cache Valley, but was not considered in this term project.  A southern break on the dam face down towards Cutler Reservoir was performed in this analysis.  The small river draining the area that would be taken over by the reservoir is the clay slough, which is practically just a drain for swampy areas in the vicinity.  Roads will bound the reservoir on the east and west, with a road crossing the clay slough directly south (no more than 50 meters) from the dam face.  
      
        ii.  Beeton/Honeyville Reservoir
            The Beeton/Honeyville Reservoir would overtake several farms and also several roads and a popular stage theater in the area.  A large bridge would need to be constructed over the reservoir about a mile downstream of the reservoir head.  A convenient river valley would house the reservoir, with the above said items being overtaken by the reservoirs.  Downstream of the reservoirs are the cities of Elwood, Bear River City, Honeyville, Corinne, Brigham City and Perry, Utah.  Flooding in Brigham City and Perry are focused on in this term project.  The items in concern in the vicinity of Brigham City is the Bear River Migratory Bird Refuge, which houses several thousand seasonal birds which call the Brigham City refuge their home in the spring and summer seasons.  Flooding in the refuge would destroy precious bedding grounds for the avian species which lodge there.  The city of Perry, Utah, contains the main thrust of the fruit crop in the state of Utah.  With many orchards of cherries, peaches, watermelon, pears and berries Perry is invaluable to the people and the state of Utah.  Flooding in the area would severely hamper the yield of fruit in the area.

    B - Area Benefits
       
        Agriculture makes up most of the land use in northern utah, more especially in the Brigham City and Perry areas.  Insured water volumes in the area for the agriculture would sure up the water resources needed.  Currently water is taken from the Bear River for irrigation, and with a reservoir the water would be saved for later use in Weber, Box Elder and Cache counties for irrigation before it drains into the Great Salt Lake.  Great Salt Lake water is, as the name implies, very saline, with brine shrimp and salt mining being the main uses of the lake.  Water supply for the wasatch front would be also vitally important to these projects reason for being constructed.

        Then by using the 3D Analyst within ArcGIS the elevation - volume relationships were calculated.  The tool (as shown in figure 6) is formally call the "Area Volume" tool because by supplying an elevation covered within the range of raster values for the file the tool will return the 2D area, 3D area (surface area) and the volume either above or below the plane being considered (as supplied).  This process was performed for 5 foot increments in the reservoirs for the Barrens, Beeton and Honeyville reservoirs.

    B - DAMBRK
       
        This model for dam failures (DAMBRK for Dam Break) uses input for reservoir such as the inflow hydrograph, upstream and downstream cross section data, various failure scenarios options, boundary conditions and dam specifications.  The dam specifications takes into account the dam crest elevation, dam base elevation, overflow spillway gate elevations, normal water pool elevation, water pool elevations for when the dam breaks, spillway coefficients, crest spillway coefficients and several other inputs.  A sensitivity analysis was not performed for the dam break specifications, most specifically for the dam break time to full breach formation, and various breach parameters.  Figure 7 shows the front end to DAMBRK.  The model was previously a DOS based software package, which was laborious to work with.  BOSS International has subsequently produced this front end which makes data entry more user friendly.  Table 1 shows the dam specifications which helped in the data entry into DAMBRK.
 

    The resulting water surfaces were imported from the export files from HEC-RAS and showing the municipality boundaries, Bear River, and the corresponding areal photographs the inundated areas can be seen.  In the following link.Barrens_Movie. you can see the progress of the amalga barrens dam break.  Each frame is 1 hour, with the whole movie taking 24 hours to show the inundation in the form of a raster.  To see the movie click on the link and then select Windows Media Player as the tool to open the animation.  The reservoir just below the dam break is Cutler Reservoir.  As can be seen in the animation no significant flooding took place in the township of Amalga.  The road on the east side of the animation is the large boundary between Amalga and most of the cheese plants.  The flooding does inundate severely a few farms with little to no physical damage besides the farms inundated.  It is interesting to note here that the highest flows in this project were seen during the dam break of the Amalga Barrens failure at 2028 cms, which is just higher than the all out break at both the Barrens, Honeyville and PMF seen downstream of the Honeyville failure, which had a maximum outflow of 1968 cms.  The strategic and convenient placement of this reservoir will aid greatly in storage volume, thus reducing the risks associated.  The importance and need of reservoirs here are very significant to storage and downstream flood protection.
    Figure 13 shows the area of Brigham City under normal Bear River level conditions.  The large ponds in the western side of Brigham City are where the Bear River Migratory Bird Refuge is located.  The seemingly white line traveling up throught the western side of Perry and the middle of Brigham City is the Interstate 15, and then the next road over from there, being the next major road to the east of I-15 is highway 89, which is none as "The Fruit Way" of Utah.  On  either side of highway 89 is the main portion of the fruit orchards in the area.  Hundreds of people from across Utah come to this area for farm fresh fruit.  To the south Willard Bay can be seen and then to the west of Willard Bay is where the Great Salt Lake begins.  

    Figure 14 shows the water levels resulting from the Beeton sunny day failure.  I identified three areas to monitor in the vicinity of Brigham City being to the north, west and western portions of Brigham City.  The inundation reported to the north in the patch followed in this figure shows that there was a 1 foot of inundation in the area.  The 9.38 feet of inundation is actually part of a pond in the bird refuge that was already there, and in the figure I actually had the flood raster on top of the lakes layer, so 9.38 is somewhat erroneous.  Significant flooding of the bird refuge can be seen.  Also noted here is the inundation of Corinne.  Throughout the scenarios significant flooding takes place in Corinne city.  Actually most of the town would be inundated with each of the scenarios considered, but I decided to focus on three areas surrounding Brigham City.

Figure 14.  Beeton Sunny Day Failure Results.

Figure 15.  Barens, Beeton Failures with PMF Results.

    In figure 16 the Honeyville sunny day failure is seen.  The results are similar to the all out break seen in the preceding figure.  This is significant showing the risk that may be secured if the Beeton dam is built.  If the storage can be spared then the Beeton dam may be a better choice in reservoir construction.  The inundation here in the Honeyville sunny day failure is still very significant in the bird refuge area.

    The largest inundation was seen in the Honeyville and Barrens failure with the PMF included as shown in figure 17.  Flooding in western Brigham City is highly prevalent and the maximum inundation in the bird refuge is almost 2 feet of water.  I did not take the time in this project to include velocity profiles, but the velocity would be the most damaging in the bird refuge area.  To the north of Brigham City 3.22 feet of inundation was reported and the maximum inundation in the area was just over 12 feet of inundation.  These areas are largely just depressions with little to no inhabitants in the immediate vicinity.  As seen in figure 17 the flood waters did not quite reach the boundaries of Perry, thus leaving the fruit orchards excluded from the inundation.  Flooding over I-15 would occur in this scenario as is seen just as the Brigham City boundaries go into a neck to head north out away from the main portion of the city.    

  

Figure 17.  Barrens, Honeyville Failures with PMF Results