North Loup Flood Reduction Study Lower Loup NRD

May 2020

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North Loup Flood Reduction Study Lower Loup Natural Resources District

Table of Contents Table of Figures ...... iii Table of Tables ...... iv Table of Appendices ...... iv Executive Summary ...... v Chapter 1. Introduction ...... 1 1.01 Project Purpose ...... 1 1.02 Project Area ...... 1 1.03 Scope Of Work ...... 2 Chapter 2. Background ...... 3 2.01 Watershed Characteristics ...... 3 2.02 Historic Flooding ...... 5 2.03 Interior Drainage ...... 6 2.04 Existing Studies and Plans ...... 10 Chapter 3. Hydrology and Hydrogeologic Assessment ...... 11 3.01 Surface Water Hydrology ...... 11 3.02 Surface Water Hydraulics ...... 11 3.03 Study Area Geology ...... 12 3.04 Groundwater Assessment ...... 12 Chapter 4. Hydrologic Alternative Identification ...... 13 4.01 Initial Alternatives ...... 13 4.02 Alternative Summaries ...... 13 No Action ...... 13 Channel Cleanout ...... 15 Berm on South Side of Mira Creek ...... 15 Watershed Flood Control Structures ...... 16 Mira Creek Bypass Channel ...... 18 Detention Basin ...... 19 Ord – North Loup Canal Bypass ...... 20 Interior Drainage, Drainage Structures/Improvements...... 21 4.03 Groundwater Recharge ...... 21 Chapter 5. Alternative Summary ...... 23

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5.01 Alternative Performance ...... 23 5.02 Permitting Discussion ...... 23 5.03 Opinion of Cost ...... 24 Chapter 6. Preferred Alternative and Recommendations ...... 25 6.01 Recommendations ...... 25 Channel Cleanout ...... 25 Large Dam ...... 25 Berm ...... 26 Combination ...... 26 6.02 Interior Drainage Improvements ...... 30 6.03 Groundwater Data Gaps ...... 31 6.04 Funding Options ...... 31 6.05 Action Items ...... 34 6.06 Disclaimer ...... 35 Chapter 7. Community Engagement...... 36 Chapter 8. References ...... 38 Appendix A: Mira Creek Hydrogeologic Assessment ...... 39 LRE Water Memorandum - April 13th, 2020...... 39 Appendix B: Detailed Cost Opinions ...... 40 Small Dam 2 ...... 40 Small Dam 5 ...... 40 Small Dam 6 ...... 40 Large Dam 1 ...... 40 Large Dam 2 ...... 40 Mira Creek Berm ...... 40 Small Bypass Channel ...... 40 Large Bypass Channel...... 40 Detention Basin ...... 40 Appendix C: Public Outreach Materials ...... 41 Meeting Items ...... 41 Project Handouts ...... 41

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TABLE OF FIGURES Figure 1: Project Area Location ...... 2 Figure 2: Mira Creek Average Monthly Discharge ...... 3 Figure 3: 2019 Land Cover ...... 5 Figure 4: Aerial Photograph of 2010 North Loup Flooding ...... 6 Figure 5: Typical North Loup Drainage Ditch ...... 8 Figure 6: Typical North Loup Culverts ...... 9 Figure 7: Modeled Existing 100-Year Flood Depths ...... 14 Figure 8: Extents of Proposed Berm ...... 16 Figure 9: Potential Dam Sites Analyzed ...... 17 Figure 10: Layout of Proposed Bypass Channels ...... 19 Figure 11: Detention Basin Locations ...... 20 Figure 12: Modeled North Loup Flooding Reduction ...... 27 Figure 13: Modeled Change in Water Surface Elevation ...... 28 Figure 14: Interior Drainage Improvement Recommendations ...... 30

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TABLE OF TABLES Table 1: Land Cover Change Assessment (2009 – 2019) ...... 4 Table 2: 2017 LLNRD HMP Flood Mitigation Strategy for North Loup ...... 10 Table 3: North Loup Hydrologic Alternatives ...... 13 Table 4: Potential for Recharge ...... 22 Table 5: Alternative Opinion of Cost Summary ...... 24 Table 6: Factors for Alternative Recommendations ...... 29 Table 7: North Loup Stakeholder Committee ...... 36

TABLE OF APPENDICES Appendix A: Mira Creek Hydrogeologic Assessment Appendix B: Detailed Cost Opinions Appendix C: Public Outreach Materials

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EXECUTIVE SUMMARY The Village of North Loup has historically suffered from repeated flooding. Three major floods have struck the Village in the last decade alone, causing widespread damage and evacuation. Mira Creek flows along the northern edge of the Village and is the primary flooding source. An inadequate interior drainage system and flat topography exacerbates flooding issues as water cannot quickly drain away from the Village.

In response, the Lower Loup Natural Resources District (LLNRD) sponsored the North Loup Flood Reduction Study in 2020. The LLNRD obtained feedback on the extent of the flooding issues and potential solutions from local stakeholders in February 2020. The public provided feedback on the study from April 17 to May 8, 2020.

A total of seven flood reduction alternatives were identified and investigated to determine their capability to reduce the impact of flooding in the Village:

• Channel Cleanout • Berm on South Side of Mira Creek • Watershed Flood Control Structures • Mira Creek Bypass Channel • Detention Basin • Ord – North Loup Canal Bypass • Interior Drainage Improvements Each alternative underwent hydrologic and hydraulic (H&H) analysis to determine their potential to lower the flood elevation within the Village. Combinations of the various alternatives were considered as well. The final recommendation to reduce flooding in the most efficient manner is a combination of channel cleanout (approximately from Highway 11 to Maple St / 485 Ave), construction of a large flood control dam on the North Branch of Mira Creek, construction of a 6,000-foot berm along the south bank of Mira Creek, and interior drainage improvements. This alternative combination has a total cost of less than $10 million and significantly reduces the threat of repetitive flooding in North Loup, with the added benefit of a large multi-purpose lake near the community. Flood depths in the Village are reduced by up to three feet, while the remaining ponding can be significantly reduced via interior drainage improvements.

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CHAPTER 1. INTRODUCTION

1.01 PROJECT PURPOSE

The Village of North Loup, located within the Lower Loup Natural Resources District (LLNRD) and Valley County, has suffered from significant flooding events for decades. In June 2010 a storm caused the entire Village to be evacuated. The Village was hit multiple times throughout 2019, starting with overland flooding in March and again in August after a six-inch rain struck Valley County. The Village is now seeking to understand the causes of flooding and identify potential solutions to reduce future flood risk. The purpose of this project is to increase the understanding of area flooding and drainage issues. Problem areas will be identified in and around the Village using maps of recent flooding events along with hydrogeological and surface water drainage information. Once the factors contributing to flooding have been determined, potential projects to prevent or reduce the flooding were recommended. Understanding the hydrology of the Mira Creek watershed and inadequacies of the interior stormwater infrastructure were key to identifying long-term flood reduction solutions. The study relies on a hydrologic and hydraulic (H&H) model which creates flood maps showing the recent and varying degrees of flooding events and how the potential projects would reduce the impacts from future flooding events.

1.02 PROJECT AREA Background

The project area is defined by the Mira Creek watershed in southeastern Valley County, Nebraska (Figure 1). Mira Creek is composed of two major tributaries; the North Branch and South Branch of Mira Creek, which come together approximately two miles west of North Loup. Mira Creek flows along the west and north sides of the Village, then east approximately two miles to its confluence with the North Loup River. The Twin Loups and North Loup Irrigation Districts serves irrigators in the region through a system of canals. The LLNRD has historical records that indicate the study area has seen significant increases in groundwater levels that could potentially be impacting both surface flows and groundwater mounding in the Mira Creek watershed and beyond.

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Figure 1: Project Area Location

1.03 SCOPE OF WORK Work on the North Loup Flood Reduction Study began in January 2020. The project scope includes:

• Data Inventory • Hydrogeologic Assessment • Alternative Identification • Hydrologic Alternative Evaluation • Feasibility Analysis • Recommendations • Stakeholder and Public Involvement This report serves as a summary of the scope of services listed above. New data collected during this effort includes hydraulic modeling, topographic survey, a limited channel survey, and geological data summarization.

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CHAPTER 2. BACKGROUND

2.01 WATERSHED CHARACTERISTICS Location

The Mira Creek watershed is composed of three HUC 12 subwatersheds; Town of North Loup-Mira Creek, South Branch Mira Creek, and North Branch Mira Creek. Combined, these subwatersheds cover approximately 45,940 acres. Soils in the region are predominately composed of Group B and C silt loam with low to moderate rates of infiltration and moderate to high runoff potential. The floodplain of Mira Creek, last updated in 2008, shows direct impacts of approximately 30 acres of the corporate limits. Mira Creek from the railroad tracks to the east has become overgrown with vegetation and obstructions creating a conveyance problem.

There is one stream gage on Mira Creek, operated by the Nebraska Department of Natural Resources (NeDNR) and located approximately 1.5 miles northwest of North Loup. The monthly averages of discharge data collected over the last decade show an increasing trend in streamflow with recent peaks in discharge occurring at greater volumes than in the past (Figure 2). Groundwater mounding in the Mira Creek watershed may be contributing to increased streamflow in the region.

Source: NeDNR, 2019 Figure 2: Mira Creek Average Monthly Discharge

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Land Use/Land Cover

Land cover data was collected from the United States Department of Agriculture (USDA) National Agricultural Statistics Service (NASS) CropScape-Cropland Data Layer online platform. A land cover change analysis was performed by comparing cropped acres from 2009 to 2019. For the purposes of this report, cropped acres include all agriculturally related activities that involve annual seeding (i.e., corn, soybeans, wheat, etc.). All other categories are considered non-cropped. This information was used to determine how much land has been converted to or from row crops in the last decade within the Mira Creek watershed (Table 1). Land that is converted to row crop can yield greater stormwater runoff, compared to pasture. The results of this analysis show that over 2,200 acres (approx. 3.5 sections) of non-row crop land cover has been converted to row crops since 2009. Additionally, a desktop assessment has shown that 4 farm ponds were removed in the conversion process. All four of these ponds were located in the North Branch Mira Creek watershed and had approximate pool areas of less than two acres. The 2019 land cover for the project area is illustrated in Figure 3.

Table 1: Land Cover Change Assessment (2009 – 2019) 2009 2019 Land Cover Type Difference (acres.) % Change (acres) (acres) Row Crop 19,089 21,314 +2,225 +11.7% Non-Row Crop 26,850 24,625 -2,225 -8.3% Source: USDA, 2019

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Figure 3: 2019 Land Cover Source: USDA, 2019

2.02 HISTORIC FLOODING In the last decade, North Loup has been impacted by three separate major flooding events. In June 2010, a dam upstream of North Loup failed after a thunderstorm released three or more inches of rain in the region. The resulting pulse of water caused extensive flooding and evacuated the Village (Figure 4). In March 2019, the Village was flooded and evacuated again when a bomb cyclone dropped heavy precipitation on frozen, saturated ground. Rapid snowmelt caused by the precipitation caused an extreme amount of runoff throughout the region. In August 2019 the Village was flooded again as a thunderstorm released five or more inches of rain in the watershed, causing damages and partial evacuation.

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Figure 4: Aerial Photograph of 2010 North Loup Flooding Source: Scott Philbrick, Valley Co. Emergency Management

2.03 INTERIOR DRAINAGE Flooding issues within the community are exacerbated by an inadequate interior drainage system. A combination of extremely flat topography within the Village and dilapidated drainage structures means that water within North Loup ponds and contributes to flooding, rather than exiting the Village quickly. A site visit to assess the interior drainage of North Loup was conducted by the project team on March 24th, 2020. This assessment included a detailed visual inspection of the main flow paths, downtown storm sewer lines, and general drainage structures throughout the Village.

Downtown North Loup has a small storm sewer system that conveys water underground on the west side of C St. There are grate inlets located along Highway 11 and a section of B St. The pipe was estimated to be 15-18 inches in diameter. The underground storm sewer runs north along C St and collects additional drainage at each block. The system drains into Mira Creek through an outflow near Mira Ave and C St.

The remainder of the City drains through a system of shallow ditches and culverts. Typically, these ditches and culverts are ill-defined, inadequately sized, and poorly maintained (Figure 5 and Figure 6). Generally, the ditches are two feet or less in depth with very gentle side slopes. There are numerous small culverts crossing roads and driveways throughout the community. The majority of these are silted in, damaged, or undersized. There is a better-defined ditch along B St. that drains nearby streets into the

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C St. storm sewer inlet. The majority of the Village north of Highway 11 drains into Mira Creek through the storm sewer system. The eastern portion of the Village generally slopes southeast around the Country Partners Co-op property. Runoff collects around the railroad tracks, then feeds to a ditch on 805 Rd. that leads to Mira Creek east of the Village. The portion of the Village south of Highway 11 generally drains to the south and collects in a ditch north of Highway 22. This southern region drains better than the rest of the Village as the ground slopes are more defined.

Areas with the greatest amount of ponding during storm/flood events are north of Highway 11. This was shown in the 2D hydraulic model and confirmed during the site visit. Stormwater runoff easily ponds due to the flat terrain and has nowhere to drain. No matter what flood control measures are implemented in the Mira Creek watershed, interior drainage issues will still cause ponding within North Loup during precipitation events. Maintenance and improvements to the interior drainage system could largely be completed by the Village staff. A complete engineering study, survey, and inventory of existing drainage structures would need to be completed before proceeding. However, general improvements would include:

• Cleaning sediment from culverts • Replacing damaged and undersized culverts • Removing sediment from ditches • Reshaping undersized ditches

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Figure 5: Typical North Loup Drainage Ditch

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Figure 6: Typical North Loup Culverts

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2.04 EXISTING STUDIES AND PLANS In the 2017 LLNRD Multi-Jurisdictional Hazard Mitigation Plan (HMP) there are several mitigation strategies identified to reduce hazards to the Village. However, only one mitigation strategy addresses flooding specifically, the details of which are outlined in Table 2.

Table 2: 2017 LLNRD HMP Flood Mitigation Strategy for North Loup Objective Reduce Stream & Drainage Bottlenecks/Flow Restrictions Description 1. Evaluate restrictions and measures to prevent or reduce flood damage 2. Implement appropriate nonstructural or structural methods on an emergency or permanent basis (monitoring or warning systems, ice jam dusting, excavation or blasting, reshaping channel, tree and debris removal, acquire property and/or construct additional channels or other flow improvements) Hazard(s) Flooding Addressed Estimated $10,000 to $50,000 for studies; $10,000+ or more to enlarge ditches, culverts, pipes; Cost unknown for stream channel, crossing structures or bridge improvements Potential HMGP, PDM, CDMG, Village taxes Funding Timeline 2 – 5 Years Priority High Status Currently digging out ditches and installing culverts Lead Agency Village Maintenance and Village Board Source: LLNRD, 2017

The Nebraska Department of Transportation (NDOT) provided a HEC-RAS H&H model and design set for a Mira Creek bridge installed on Highway 11 in 2020. This project widened the bridge opening and realigned the highway to the west. The project provided ordinary high-water elevations and information that was used in the new H&H model used for alternative evaluation.

The North Loup Irrigation District improved laterals in 2014 and provided design information. This information provided insight to the location of buried laterals and turnouts installed near the Country Partners Co-op.

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CHAPTER 3. HYDROLOGY AND HYDROGEOLOGIC ASSESSMENT It should be noted that the hydrogeologic assessment portion of this chapter includes a summary and findings from LRE Water’s technical memo provided to JEO for the alternative evaluation on April 13, 2020. Technical information from that memo is integrated into this report. The purpose of the technical memo was to evaluate the potential impacts to groundwater of structures built to reduce surface water flooding. To accomplish this goal, surface water and groundwater hydrology underwent separate assessments, as outlined below. The full report and figures are included in Appendix A.

3.01 SURFACE WATER HYDROLOGY All Mira Creek streams and canals are intermittent except for the lower portions of the North and South Branches of Mira Creek, and Mira Creek itself, according to the National Hydrology Dataset, USGS. The portions that are perennial are classified as receiving the majority of their flow under normal conditions from groundwater discharge from the principal aquifer. Perched groundwater may also contribute to streamflow. However, there is currently not enough information to identify perched systems across the watershed, and in particular in the areas near the proposed flood retarding structures.

Hydraulic design information for the stream channel was obtained from the NDOT for the recently replaced Highway 11 bridge. The Mira Creek stream gage data was also evaluated, however the period of record for the gage is relatively short. A HEC-HMS model was built by the project team with the purpose of calculating an excess precipitation hydrograph to use in a HEC-RAS 2D model using a “rain on grid” approach. A weighted average Natural Resources Conservation Service (NRCS) curve number was used to account for any infiltration. This method allows for potential upstream structures such as dams and detention structures to be better analyzed. The model utilized a 24-hour storm duration for peak flows, providing a reasonable estimation of the peak flow rates in Mira Creek. The peak flow rates correlated well with the stream gage analysis and NDOT bridge design data.

3.02 SURFACE WATER HYDRAULICS A 2D HEC-RAS model was created using a combination of Light Detection and Ranging (LIDAR) elevation data and limited survey data. A 2D grid was employed over the entire drainage area, with North Loup having a more refined grid size to provide a balance between proper terrain definition and model run time. All major bridges and culverts were modeled, including the future Valley County bridge on 785th Avenue (according to the design plans). Existing conditions and all potential alternatives were modeled using 100-year (1% annual exceeding probability) and 50-year (2% annual exceeding probability) storm events with a 24-hour rainfall. A 48-hour model run time was used to allow the peak flows from the full watershed to sufficiently pass through North Loup.

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3.03 STUDY AREA GEOLOGY The watershed area lies in the dissected loess plains and alluvial valley topographic regions. The primary geologic units present below the watershed include Quaternary-age clay, loess, and fine-grained sands underlying the dissected plains, and Quaternary-age alluvial silt, sand, and gravel in the alluvial valleys. The Quaternary deposits are underlain by the Tertiary-age Ogallala Group, which consists of silt, sand, and gravel, and semi- to consolidated sandstones, siltstones, and some limestones. The Ogallala makes up the principal hydrogeologic units of the High Plains aquifer, and the principal aquifer in the watershed. The major stratigraphic units above the Ogallala are arranged into three major categories:

• Clay, silt, and topsoil (low-permeable confining unit) • Sandy clay (moderate-permeable leaky confining unit) • Sand and gravel (high-permeable aquifer material)

3.04 GROUNDWATER ASSESSMENT The principal aquifer is seen under three conditions in the study area; water table, semi-confined or leaky, and confined. The majority of the watershed is found to be under semi-confined or leaky, and confined conditions. The aquifer condition was determined by comparing measured depth to water level at the time of well installation relative to the stratigraphy on the cross sections. If the Ogallala is overlain by clay and silt it is characterized as confined, and semi-confined if overlain by sandy clay.

The groundwater potentiometric surface was determined by subtracting the interpolated potentiometric surface created from water level measurements taken at the time of well installation from the current ground surface elevation as determined by LIDAR. This analysis confirmed that groundwater generally flows from upland areas towards Mira Creek and the North Loup River.

Groundwater levels across the watershed have increased since predevelopment from approximately 5 to 50 feet based on published maps by NeDNR. Water level data from three observation wells in the watershed from the LLNRD confirm NeDNR’s measurements showing water levels in the loess plains have increased as much as 30 to 40 feet since the mid-1970s, creating a groundwater mound in this region. Depth to groundwater is approximate and was determined by subtracting the interpolated potentiometric surface created from water level measurements at the time of well installation from the current ground surface elevation as determined by LIDAR.

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CHAPTER 4. HYDROLOGIC ALTERNATIVE IDENTIFICATION

4.01 INITIAL ALTERNATIVES JEO worked closely with residents of North Loup and the LLNRD to develop a list of initial alternatives to address flooding issues based upon existing data and locations that provide the greatest flood risk reduction. A compiled list of these alternatives is available below in Table 3. Complete summaries of each alternative are available in the following chapter. These alternatives were further refined and narrowed down based on feasibility, cost, and ability to reduce flood risks to North Loup.

Table 3: North Loup Hydrologic Alternatives Alternative No. Name Description No actions taken – model the existing conditions of Mira 1 No Action Creek and North Loup. Improve the channel of Mira Creek through North Loup and 2 Channel Cleanout downstream for increased floodwater conveyance. Berm on South Side Build a berm on the southern bank of Mira Creek through 3 of Mira Creek North Loup. Watershed Flood Construct one or more flood control dams throughout the 4 Control Structures Mira Creek watershed. Mira Creek Bypass Construct one or more bypass channels between meanders 5 Channel of Mira Creek to relieve floodwater back-up. Construct one or more detention basins to delay or prevent 6 Detention Basin floodwaters from reaching North Loup. Construct one or more bypass channels to deliver Ord – North Loup 7 floodwaters from Mira Creek or its tributaries to the Ord – Canal Bypass North Loup Canal. Interior Drainage May include construction or cleanout of ditches, culverts, 8 Improvements and other drainage structures.

4.02 ALTERNATIVE SUMMARIES

NO ACTION

This alternative was evaluated first to define current conditions in the Mira Creek watershed using the newly established H&H model. The existing FEMA 2008 floodplain map does not appear to accurately represent the current conditions, verified by data collection, photos from the 2010 and 2019 flood events, and JEO’s modeling. In the no action scenario, no additional structural or nonstructural flood control measures are implemented in North Loup or the Mira Creek watershed. Modeling was completed to provide a baseline which other alternatives can be compared against. Additional modeling was completed for all other alternatives to evaluate their effectiveness at reducing flooding in North Loup as compared to this baseline scenario. The No Action, 100-year flood event model, can general be described as follows:

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• Modeled precipitation begins at hour 10:50, with the peak of the hydrograph occurring at 12:20. • At 13:00 hours, Mira Creek begins filling to the banks and floodwaters begin progressing downstream. • At 15:00 hours, Mira Creek has overtopped the banks in North Loup and the Village has begun flooding. • Maximum flood extents in North Loup occur between 16:00 – 18:00 hours, with flood levels gradually receding until 36:00 hours. • Note that this model does not include any interior drainage structures. The interior ponding would drain away slightly faster than the modeled times.

Flooding extents from the 100-year storm model cover nearly everything north of Highway 11, matching up well with aerial photographs of the 2010 flood event (Figure 7). The portion of North Loup south of Highway 11 sees no significant flooding from Mira Creek. Flood depths range from 1-2 feet in most areas, but as deep as 4 feet in low areas and ditches. For the 100-year storm event a maximum flow rate of 9,940 cfs (cubic feet per second) was observed, and a total flow volume accumulation of 8,670 acre- feet over a 48-hour period.

Figure 7: Modeled Existing 100-Year Flood Depths

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CHANNEL CLEANOUT

Channel cleanout includes removing downed trees, overgrown brush and branches, and any other debris in Mira Creek that may be obstructing flows. A channel cleanout would increase the conveyance of the channel, allowing floodwaters to flow at a higher velocity and lower the water surface elevation during flood events. For purposes of this study, it was assumed that channel cleanout would occur from Highway 11 downstream for approximately one mile.

The channel cleanout alternative was modeled by altering the No Action model to represent a more streamlined channel through North Loup. The model results show the water surface elevation lowered by approximately 0.5 feet at the Highway 11 bridge. Channel cleanout does not significantly change the flooding extents in the Village but does have a positive effect on the conveyance of floodwaters. Channel cleanout is a low-cost alternative that could be performed by Village staff in combination with other alternatives to mitigate flooding impact to North Loup.

BERM ON SOUTH SIDE OF MIRA CREEK

This alternative consists of an approximately 6,000-foot berm constructed on the south bank of Mira Creek from the southwest side of the Highway 11 bridge to the railroad tracks east of the Village (Figure 8). The average height of the berm is approximately 4.5 feet but varies slightly with the terrain. The berm follows the south bank of Mira Creek from the Highway 11 bridge to north of Central Ave before turning north of the east bank as the stream meanders. The end of the berm ties into the railroad tracks northeast of the Village. The proposed berm footprint goes through several residential lots and would require residential and agricultural buyouts to construct.

The berm provides significant flooding relief to the Village. At a proper height the berm prevents all flood water from Mira Creek from entering North Loup by forcing the water north into the agricultural fields instead. The berm only physically separates Mira Creek from North Loup and does not reduce the peak flow rate, volume, or flood heights in the channel. The increased flood extents to the north of the Village due to the berm are relatively small and do not increase the maximum water surface by more than 1 foot in any area. Therefore, flooding easements would likely be unnecessary.

A majority of the cost to build the berm would be due to land buyouts. A slight change in the berm’s height would not have a significant effect on the overall cost. Therefore, it would be prudent to design the berm to protect North Loup from a 100-year event. The berm as evaluated and estimated would not be an official Untied States Army Corp of Engineers (USACE) certified levee. Meeting USACE levee certification would greatly increase the cost and time required to build such a structure.

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Figure 8: Extents of Proposed Berm

WATERSHED FLOOD CONTROL STRUCTURES

Due to the size and topography of the Mira Creek watershed there were multiple locations to model potential flood control dams. Six potential sites were initially identified for small detention structures, or dry dams (labeled Dams 1 – 6). Dry dams are designed to retain floodwater for 24 to 48 hours, allowing land use to be used for agricultural uses the majority of the time. Furthermore, dry dams are far less likely to contribute to groundwater recharge. Of these initial sites, several were eliminated due to potential land and soil issues. Dams 2, 5, and 6 were selected to be modeled together as one alternative. These are small dams that would likely be designed to follow NRCS Pond 378 standards for embankment ponds.

One location was identified for a larger retention structure, meaning it would retain a pool of water throughout the year. There were two potential dam alignments modeled at this location, referred to as Large Dam 1 and 2. All of the dams are located along the North Branch of Mira Creek (Figure 9). Topography along the South Branch of Mira Creek and the presence of canal laterals limits any opportunities to build dams.

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Figure 9: Potential Dam Sites Analyzed Three scenarios were modeled for these potential dams; Small Dams (2, 5, and 6), Large Dam 1, and Large Dam 2. The effects of the Small Dams 2, 5, and 6 were relatively small. The peak flow rate during a 100-year storm event was reduced by 1,420 cfs and the volume accumulation was reduced by 830 acre- feet. The effects of the Large Dams were much greater. Both Large Dam 1 and Large Dam 2 reduced the 100-year storm even peak flow by 3,610 cfs and the volume accumulation by 5,110 acre-feet. The potential flooding reduction in North Loup from either of the Large Dam configurations was moderate. North Loup still experienced flooding from Mira Creek, but the flood depths were reduced by 1 – 2 feet in some areas. The Large Dam alternative would have potential secondary benefits such as recreation, wildlife habitat, and aquatic habitat improvements.

The Large Dam alternative could also be configured as a dry dam if the LLNRD wishes to avoid potential groundwater impacts or does not desire a large recreation structure in this region. A dry dam uses a modified ported riser structure to prevent permanent storage. This would allow the structure to have temporary flood water detention benefits with no permanent water retention. The overall flood reduction benefits would remain the same.

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It is important to note that a detailed geotechnical analysis is necessary to determine the complete feasibility of any of the dams and was not completed as part of this study. A separate detailed H&H design and spillway routing is needed to better define necessary dam size, storage, and spillway elevations. This study looked at the maximum potential flood reduction for each dam location, but the actual feasible size of the dams once final design is complete may be smaller with lessened flood reduction.

MIRA CREEK BYPASS CHANNEL

Two options of a bypass channel to displace flows from Mira Creek during flooding events were evaluated. Due to the high peak flow rates during large storm events, the bypass channel would need to match the existing channel in depth and width, while having a significant floodplain area to convey larger flow events. An optimal path for a potential bypass channel is north of Mira Creek through the agricultural fields south of 806 Rd. Several alignments, channel widths, and depths were explored (Figure 10). Initially a channel with similar dimensions to Mira Creek was cut into the existing terrain connecting the Creek downstream of the Highway 11 bridge to a meander stream of the railroad bridge. This resulted in a minor reduction of flooding in North Loup as most flow was still confined by the original channel and floodplain.

A larger and longer channel lined by berms to contain flows was also modeled. This channel started at the existing channel west of the Highway 11 bridge and connected to the existing channel near 806 Rd. This alternative greatly reduced flows in Mira Creek and achieved significant flood reduction in North Loup by rerouting most flow from Mira Creek to the north. This option is significantly more costly due to the large land buyouts, excavation and fill requirements, and construction of several channel crossings / bridges at highways, railroads and county roads. However, there would be no residential impacts to North Loup.

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Figure 10: Layout of Proposed Bypass Channels

DETENTION BASIN

A large detention basin was modeled on the South Branch of Mira Creek. This basin would consist of approximately 320 acres divided by Highway 22 (Figure 11). These are low lying areas where the Creek gradually meanders through agricultural land. These were modeled as two separate but connected detention structures, one north of Highway 22 at 120 acres, and one south of Highway 22 at 200 acres of total surface area. Small connections were added between the cells to allow detained floodwater to gradually drain from the cells back into Mira Creek.

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Figure 11: Detention Basin Locations At a theoretical maximum during a 100-year storm event, 1,890 acre-feet of floodwater was retained over a 48-hour period. The maximum flow rate to Mira Creek was reduced by 2,550 cfs. This resulted in a moderate flood reduction in North Loup. The water surface elevation at the Highway 11 bridge was reduced by 1.2 feet for a 100-year storm event. From a construction standpoint, the amount of storage needed equate to approximately 3 million cubic yards of soil excavation. Creating a detention cell of this size would require considerable cost and effort. However, the amount of soil removed could be reduced by any amount, reducing cost and flood mitigation as well. A detention basin of any smaller size is possible, but the flood reduction potential is then dependent exclusively on the size of the basin.

ORD – NORTH LOUP CANAL BYPASS

This alternative consists of building a channel connecting Mira Creek to the Ord – North Loup Canal to convey floodwaters away from the Village. The Ord – North Loup Canal is located approximately 0.5 miles west of the Village and is operated by the North Loup Irrigation District. This canal generally flows from north to south, presenting the opportunity for excess floodwaters to be removed from Mira Creek and flow south away from the Village. Initial investigation revealed that this alternative would not feasibly reduce flooding to North Loup due to the terrain constraints, length of bypass required, and lack

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of channel capacity in the canal. This alternative was not investigated further nor modeled as a standalone option, or in combination with other potential alternatives.

INTERIOR DRAINAGE, DRAINAGE STRUCTURES/IMPROVEMENTS

As explored in Chapter 2, regardless of what flood control measures are implemented in the Mira Creek Watershed interior drainage issues will still result in ponding and localized flooding within North Loup. Maintenance and improvements to the interior drainage system could largely be completed by the Village maintenance staff. A complete engineering study, survey, and inventory of existing drainage structures would need to be completed before proceeding. However, general improvements would include:

• Cleaning sediment from culverts • Replacing damaged and undersized culverts • Removing sediment from ditches • Reshaping undersized ditches

4.03 GROUNDWATER RECHARGE Groundwater levels in the Mira Creek watershed have been rising in recent years due to a groundwater mounding effect caused by excessive recharge. Mounded groundwater may be contributing to flooding in North Loup through increased baseflow in streams and reduced infiltration opportunities. Several of the above alternatives have the potential to provide groundwater recharge, which may contribute to additional groundwater mounding. Table 4 provides a ranking for relative potential for infiltration and groundwater recharge for each proposed structure. This ranking is a qualitative assessment of each structure’s potential to lose water to groundwater by infiltration and the ranking is based significantly on the thickness of the low-permeable clay and silt zone that underlies each potential structure site. Structures with less clay and silt have a greater potential to lose water to the principal aquifer. It also takes into account the depth to the potentiometric surface and if the unit overlying the principal aquifer is confining or leaky. This also assumes the water level in the structure remains higher than the groundwater level, creating an induced recharge condition. Note that if the water level in the structure falls below the level of the groundwater, there is a potential for the structure to fill with groundwater (LRE 2020).

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Table 4: Potential for Recharge Shallowest Aquifer Stream UNL GW Change Potential for Structure Depth to GW Type Perennial? (feet) GW Recharge (feet) Leaky- Dam 2 No +20-30 11 High confined Leaky- Dam 5 No +20-30 33 Low confined Leaky- Dam 6 No +10-20 15 Moderate confined Leaky- Large Dam Yes +20-30 2 High confined Detention Cells Confined Yes +20-30 19 Low Bypass Channel Transitional Yes +5-20 0 High

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CHAPTER 5. ALTERNATIVE SUMMARY

5.01 ALTERNATIVE PERFORMANCE The H&H model analysis has shown that there is not a standalone alternative that results in the level of flood risk reduction sought by the LLNRD and Village. Therefore, several combinations of alternatives were modeled to understand the cumulative effects of different alternatives. The alternative combinations analyzed as part of this study were:

1. Large Dam and Detention Basin 2. Small Bypass Channel and Berm 3. Channel Cleanout, Berm, and Large Dam

Combination 1 put together the Large Dam and detention basin. This resulted in a large cumulative effect on floodwater reduction. Combining the ability of both structures to separately detain runoff from both the North and South Branches of Mira Creek showed a significant reduction in peak flow rate and floodwater volume in Mira Creek.

Combination 2 put together the smaller bypass channel and the berm on the south bank of Mira Creek. These two alternatives work well together as the excavated material from the channel could be used to construct part or all of the berm. However, the results show little difference in flood reductions from the berm alternative alone. Construction of the berm is sufficient alone and would not need to be combined with other alternatives if this is the selected method.

Combination 3 put together the Large Dam (either alignment), channel cleanout, and the berm. This combination resulted in significantly reduced flooding. Floodwater retention of the dam and the barricading effect of the berm resulted in no flooding reaching North Loup. The channel cleanout aids this by increasing conveyance capacity of Mira Creek. The Large Dam reduces peak flows entering Mira Creek, allowing the berm to be shorter resulting in reduced cost and property required. Additionally, this combination reduces the adverse impact of excess flood waters being pushed north out of Mira Creek into agricultural lands. Without the Large Dam, the berm alone would result in agricultural flooding several feet deep directly north of North Loup. This combination also provides redundancy; if one structure were to fail, the other would still provide flood protection to North Loup.

5.02 PERMITTING DISCUSSION There are several significant permits to obtain from state and federal agencies to obtain authority to construct any major flood control project including a Clean Water Act Section 404 permit from the USACE, storage permit from NeDNR, floodplain permits from Valley County and NeDNR, and Stormwater Pollution Prevention Plan (SWPPP) from the Nebraska Department of Environment and Energy. Water storage permits could require offsets for flow depletions to the Lower Platte River to maintain compliance with the state and federal laws requiring a minimal flow for endangered species.

Most notable is the Section 404 and the complexity of the permit is directly tied to the impacts of fill within wetlands or alterations to stream channels and may require a nationwide permit (NWP) with no mitigation, a NWP with mitigation, or an Individual Permit (IP). The study did not include field verification of wetlands or estimated impacts. It is likely that the channel cleanout and interior drainage

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improvements could be completed without a 404 permit, or at least with a relatively simple NWP. The berm, depending upon wetlands impacted, could also be permitted with an NWP, possibly with mitigation. Dams of significant size often trigger an IP, due to impacts to the waterway. An IP requires an environmental analysis of practicable alternatives to find the least environmentally damaging practicable alternative (LEDPA), compliance with the National Environmental Policy Act (NEPA), alternative evaluation, and public comment period. IPs can take up to two years and add significant cost to the project. Impacts to streams also require use of the Nebraska Stream Condition Assessment Procedure (NeSCAP) to determine the level of stream mitigation.

Permitting cost will be determined during conceptual design (30%) of the preferred alternative. Section 404 permitting would occur during the final design process.

5.03 OPINION OF COST Preliminary opinions of cost have been prepared for the purpose of making a monetary comparison between the proposed alternatives (Table 5). Material and equipment costs were determined by review of local construction projects of similar nature and consultation with various material and equipment manufacturers and suppliers. Material and labor costs have increased over the recent years resulting in increasing construction, operation, and maintenance costs. Market conditions indicate that this trend will likely continue in the future at varying rates. The cost opinions have been prepared based on present (2020) value construction costs for comparison purposes. Detailed individual cost opinions are available in Appendix B, which include quantity estimates for itemized construction costs, future engineering and testing costs, land acquisition estimates, and general permitting costs (included in the engineering fee).

Table 5: Alternative Opinion of Cost Summary Alternative Construction Cost Engineering Cost Land Cost Total Cost Channel Cleanout $100,000 $25,000 $0 $125,000 Dam 2, 5, and 6 $553,000 $135,000 $820,000 $1,508,000 Large Dam 1 $2,627,000 $420,000 $4,100,000 $7,147,000 Large Dam 2 $2,923,000 $464,000 $4,150,000 $7,537,000 Berm $520,000 $160,000 $660,000 $1,340,000 Bypass Channel $393,000 $84,000 $100,000 $577,000 Longer Bypass $13,452,000 $2,118,000 $500,000 $16,070,000 Channel Detention Basin $15,925,000 $1,693,000 $1,800,000 $19,418,000 Berm + Bypass $913,000 $244,000 $760,000 $1,917,000 Channel Berm + Large Dam $3,147,000 $580,000 $4,760,000 $8,487,000 Berm + Large Dam + $3,247,000 $605,000 $4,760,000 $8,612,000 Channel Cleanout

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CHAPTER 6. PREFERRED ALTERNATIVE AND RECOMMENDATIONS

6.01 RECOMMENDATIONS A combination of four alternatives are recommended for consideration based on the results of this study. The recommended alternatives are listed below with their estimated costs in 2020 dollars:

1) Channel cleanout ($125K), 2) Construction of a large flood control dam ($7.1 – 7.5M), 3) Construction of the berm along Mira Creek ($1.3M), and; 4) Interior drainage improvements ($24k / block). Factors considered include flood reduction benefit, floodwater detention, peak flow rate reduction, construction cost, land acquisition, groundwater recharge, public perception, and design and permitting feasibility. Table 6 shows a summary of all the alternatives and the primary factors that went into the recommendation summary. Each recommended alternative is briefly discussed below.

CHANNEL CLEANOUT

Channel cleanout has the lowest cost to benefit ration of any alternative. This is a low-cost option that would provide immediate benefit. The project could be publicly bid, or gradually performed by the Village staff with support from the LLNRD. Cleaning the channel would help increase floodwater conveyance and lower the potential flooding height. In some areas the banks could be pulled back to a more gradual slope, further enhancing the conveyance and positive effects. Depending on the severity of the flooding event, a cleaned-out channel could be the difference between Mira Creek staying in its bank or flooding in the Village. Channel cleanout would last approximately 5-10 years before it would need to be performed again due to collection of flood deposited debris and vegetative growth. The Village should consider working with LLNRD to extend the location of the existing stream maintenance area to the confluence with the North Loup River. Note that channel cleanout may be expanded east and west beyond North Loup as far as desired at additional cost and maintenance requirements.

LARGE DAM

A large dam on the North Branch of Mira Creek would provide moderate floodwater reduction in North Loup. Depending on the final location and sizing of the dam, it could reduce the peak flow in North Loup by several thousand cfs. A large flood control dam is expensive, requiring significant land acquisition and greater engineering and permitting requirements. However, the large dam could act as a multi-purpose structure providing public recreation facilities as well as enhanced fisheries and wildlife habitat. It is essential to perform a preliminary geotechnical investigation to determine the suitability of the geography to properly construct a dam and hold water. A detailed hydrology and spillway routing procedure is also recommended to determine the exact height, pool elevation, and flood retention of the dam. Furthermore, a detailed hydrogeology study is recommended to determine the extent of groundwater recharge potential to the Mira Creek valley. The benefit-cost ratio of a large dam would be stronger should it offer the regional recreational benefits, which given the value of the downstream

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properties, may be required to obtain a benefit-cost ratio greater than 1.0, a requirement of many funding agencies.

BERM

A berm along the southern bank of Mira Creek through North Loup provides the highest amount of flood protection for the lowest cost of all the structural alternatives. The berm would protect the Village from flooding below the designed height by pushing all floodwaters to the north. The construction cost of the berm is relatively low, but land acquisition and public perception of numerous residential buyouts could be a significant challenge. As proposed, the berm would not be a certified federally accredited levee and could be designed to meet varying levels of protection (such as a 50-year flood or 100-year flood). The berm alignment is not final but is representative of the best location. A berm would not contribute to any groundwater recharge and could be designed and permitted relatively quickly. However, residents of North Loup would not be provided any relief from flood insurance requirements without meeting the federal levee certifications.

COMBINATION

The best combination of all the alternatives considered is channel cleanout, the berm, and the large dam. The floodwater detention effects of the dam could lead to a lower berm height required, and the channel cleanout would add little extra cost and increase the overall flood reduction capability of the project as a whole. Altogether, this alternative combination would cost less than $10 million and significantly reduce the threat of repetitive flooding in North Loup, with the added benefit of a multi- purpose lake. Figure 12 compares the existing flooding extents in North Loup and the modeled reduced flooding extents after construction of the combined flood reduction alternatives. Figure 13 shows the change in Water Surface Elevation (WSE) from the existing conditions to the recommended combination of alternatives. Flooding depths in North Loup are reduced by up to three feet, while flooding depths in the agricultural land north of the Village are increased in limited areas by up to one foot. It is important to note that the remaining pooling in the community is a result of the model illustrating interior drainage deficiencies.

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Figure 12: Modeled North Loup Flooding Reduction

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Figure 13: Modeled Change in Water Surface Elevation

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Table 6: Factors for Alternative Recommendations Storm Flow Vol. WSE Land Flood GW Recommend Alt. Freq. Reduction Reduction Reduction Cost Acquisition Reduction Recharge Alternative (yrs) (CFS) (AC-FT) (FT) (ac) Dams 2, 5, 6 100 1,420 830 0.3 Low $$ 26 Low-High No Dams 2, 5, 6 50 1,220 610 0.3 Big Dam 1 = 36" 100 3,610 4,950 1.1 Moderate $$$ 310 High Yes Big Dam 1 50 2,800 3,750 1 Big Dam 2 = 36" 100 3,580 4,920 1.1 Moderate $$$ 312 High Yes Big Dam 2 50 2,770 3,720 1 Berm 100 30 0 -0.7 Significant $$ 20 Low Yes Berm 50 20 0 -0.5 Bypass Channel 100 0 0 0 Low $$ 10 High No Bypass Channel 50 0 0 0 Bypass Channel Large 100 80 0 8.7 Significant $$$$ 50 Low No Bypass Channel Large 50 80 0 8.2 Channel Cleanout 100 -100 -10 0.3 Low $ None Low Yes Channel Cleanout 50 -50 0 0.2 Detention Pond 100 2,550 1,890 1.2 Moderate $$$$ 180 Low No Detention Pond 50 1,910 1,340 0.6 Big Dam and Detention 100 7,970 7,550 4 Significant $$$$ 490 Low-High No Big Dam and Detention 50 5,840 4,590 4 Small Bypass Channel and 100 20 0 -0.7 Significant $$$ 30 Low-High No Berm Small Bypass Channel and 50 20 0 -0.5 Berm Berm and Big Dam 100 3,590 4,910 0.7 Significant $$$ 330 Low-High Yes Berm and Big Dam 50 2,780 3,730 0.7 Channel Cleanout, Berm, 100 3,580 4,910 0.9 Significant $$$ 330 Low-High Yes and Big Dam Channel Cleanout, Berm, 50 2,770 3,730 0.8 and Big Dam

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6.02 INTERIOR DRAINAGE IMPROVEMENTS Interior drainage improvements will not reduce flooding from Mira Creek, but will reduce ponding that occurs due to precipitation falling within the Village. The majority of this work could be accomplished by local staff, or a local contractor with minimal equipment required. General improvements were outlined in Chapter 2, but more specific recommendations are listed below and illustrated in Figure 14.

• Perform ditch and culvert cleanout in the northeastern quarter of the Village • Increase conveyance along B St and C St to improve the efficiency of existing underground storm sewer

The preliminary cost estimate for ditch and culvert cleanout is $6,000 per side of street per block, or $24,000 per square block. While general ditch and culvert cleanout are the initial recommendation, developing a Stormwater Master Plan for North Loup is also recommended. This Master Plan would include a detailed topographic survey, interior hydrology and hydraulic analysis, and refined improvement priorities and cost estimates.

Figure 14: Interior Drainage Improvement Recommendations

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6.03 GROUNDWATER DATA GAPS The groundwater assessment results provided by LRE Water are based on currently available information outlined above. Site-specific hydrogeologic data are very limited or absent in the area of each structure. Therefore, information on the hydrostratigraphic layers, depths to current groundwater levels, and possible perched water zones that could affect infiltration and potential groundwater recharge are uncertain and additional field data collection would be required to support final design. To address these uncertainties, site-specific investigation activities are recommended for each of the preferred alternative for further evaluation. The activities should include, but not limited to the following: 1) Develop a subsurface investigation work plan and select locations for test hole drilling, piezometer installation, groundwater level monitoring, hydraulic conductivity testing, and the necessary geotechnical work; 2) Implement the work plan to characterize the thickness, hydraulic properties, and types of unconsolidated materials down to the top of the Ogallala; 3) Install pairs of nested piezometers around each structure to determine the depths to groundwater, perched groundwater zones, if present, and measure the vertical and horizontal hydraulic gradients; 4) Collect necessary geotechnical information that can be used to estimate infiltration rates; and, 5) Prepare site-specific geotechnical and hydrogeologic assessment reports.

6.04 FUNDING OPTIONS There are several available funding sources for flood risk reduction projects available to the Village and/or LLNRD, as a partner. A few of the most notable and readily available are noted below. This list is not a complete list of all available sources.

Water Sustainability Fund (WSF)

The Nebraska Natural Resources Commission (NRC) provides up to $11M annually to projects that lead to the sustainability of water resources, protection of watersheds, improvement of water quality, and allows future generations to meet water needs. The WSF is administered by the NeDNR. Applications are due July 31, annually. The WSF requires a benefit-cost discussion and has funded flood risk reduction structures since its initiation in 2015.

Watershed and Flood Prevention Operations (WFPO)

The Natural Resources Conservation Service (NRCS) administers the WFPO program, through Public Law 566. The WFPO program was re-initiated in 2016 and funds 100% of watershed planning, which is required to obtain engineering and construction funding. NRCS also covers up to 100% of eligible flood prevention projects, outside of land rights and permitting (which could be covered by WSF). Applications are typically accepted in April annually, however a second application deadline has been announced for July 31, 2020. The NRCS is favorable to projects that have had studies completed by sponsors with a reputation for completed large-scale projects making Mira Creek a favorable application in the future. The WFPO planning process is typically 24-months, but would be significantly expedited by the information in this study.

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Nebraska Environmental Trust (NET)

The NET is a state-funded grant program that serves to conserve, enhance, and restore natural environments. The NET would not fund a flood control project but would consider portions of a project that establish natural habitat and provide a connection to the natural environment. For example, NET may fund establishment of native prairie habitats, aquatic habitat enhancements, wetland creation, and similar components of the large dam alternative.

FEMA Hazard Mitigation Grant Program (HMGP)

After a presidential disaster declaration, FEMA allocates through its HMGP funding to states to mitigate future damages. Up to 75% of the cost for eligible projects is covered. Project types could include property acquisition and structure demolition or relocation, and structure elevation. The Village would need to maintain participating in the LLNRD Hazard Mitigation Plan (HMP) and include these types of projects as potential actions in the HMP.

Community Development Block Grant Program (CDBG)

The Small Cities CDBG Program is administered through the Nebraska Department of Economic Development and helps smaller local governments fund community projects that might not otherwise be financially feasible. Through funding from the United States Department of Housing and Urban Development, the program allows each community to determine which projects are most needed. Projects must focus on housing, neighborhood revitalization, commercial revitalization, or economic development.

The national objectives of the program are to benefit Low- and Moderate-Income (LMI) persons, eliminate slum or blight in communities, and address urgent development needs. A community must have an LMI percentage greater than 51% to be eligible for CDBG funding. The Village is currently 43.94% LMI and therefore not eligible to apply for CDBG funds (HUD, 2020). However, the CDBG program does allow for a local challenge to their percentage requirements if the community has reason to believe that their area is actually greater than 51% LMI and has been misrepresented. This challenge process requires that the Village conduct a statistically valid income survey of the entire service area, pursuant to CDBG methodology.

It is recommended that the Village seeks the assistance of an experienced individual or organization familiar with CDBG survey requirements to oversee this process. Failure to comply with CDBG methodology will invalidate the results of the survey. The survey process will take additional time to complete and the outcome is not guaranteed. The Village must carefully weight the potential inflationary cost of construction against the potential benefits of an added grant.

Nebraska Department of Environment and Energy – Clean Water State Revolving Fund

Based on the 2012-2016 American Community Survey 5-Year Estimate, the median household income of the Village is $44,028 with a margin of error of ±$19,751. Given this value, the Village may be eligible for a 1.5% + 1.0% loan from the Clean Water State Revolving Fund Program, a Small Town grant, and potential loan forgiveness.

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Highway Allocation Fund

The Highway Allocation Fund consists of revenues generated from the collection of motor fuel taxes, vehicle registration fees, vehicle sales tax, and investment earnings. These funds are designated for projects to rehabilitate, construct new, or improve existing streets, intersections, sidewalks, bikeways and trails, safety projects, intelligent transportation infrastructure, and landscaping in connection with street improvement. The Highway Allocation Fund requires local match funding.

General Obligation Bonds

General Obligation bonds are backed by property taxes and can be issued by the Village for a wide array of community improvement projects.

Joint Public Agency Act

The Joint Public Agency Act allows local governments to make the most efficient use of their taxing authority by cooperating with other governmental units on a basis of mutual advantage. This allows a community to provide services and facilities in a manner pursuant to forms of governmental organization that will accord best with geographic, economic, population, and other factors influencing the needs and development of local communities.

Two or more public agencies may enter into agreements with one another for joint or cooperative action pursuant to the Joint Public Agency Act. Any combination of two or more public agencies may create one or more joint public agencies to exercise the powers and authority prescribed by the Joint Public Agency Act.

Local Option Sales Tax

Any Nebraska county or incorporated municipality may impose a local sales and use tax upon approval by a majority of their voters in a regular election. The local tax applies to the identical transactions subject to the state sales and use tax, with the exception of direct-to-home satellite programming. Local option taxes of 0.5¢, 1¢, and 1.5¢ may be approved by city or county voters. The tax is collected and remitted to the state and is then allocated back to the municipalities after deducting the amount of refunds made and three percent administrative fee.

Effective July 19, 2012 and pursuant to §77-27,142, municipalities may, with voter approval, enact a sales and use tax equal to 1.75¢ to 2.0¢. The proceeds from the rate in excess of 1.5¢ shall be used for public infrastructure projects or voter-approved infrastructure related to an economic development program as defined in section 18-2705 of the Nebraska Revised Statutes.

Municipal Borrowing

The mayor and council of any city and the board of trustees of any village, in addition to other powers granted by law, may borrow from a state or federally chartered bank, savings bank, building and loan association, or savings and loan association, for the purchase of real or personal property for any purpose for which the city of village is authorized by law to purchase property or construct improvements. Such loans shall not be restricted to a single year and may be repaid in installment payments.

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Tax Increment Financing (TIF)

TIF is a tool that encourages private development in areas experiencing blight and disinvestments, typically in or near a downtown area. A TIF program provides a method for financing public costs associated with a private development project by using the projected increase in property tax revenue resulting from the private development. TIF bonds allow the developer to retire the “public costs” over a period of 15 years. During the time the bonds are outstanding, each taxing jurisdiction receives its original share of tax revenue or “pre-TIF project tax revenues.” The advantage of TIF is that it enables a local government to borrow against future tax revenues generated by a redevelopment project. Further details are available in Section 18-2101 through 18-2154 of the Nebraska Revised Statutes.

USDA Rural Development Community Facility Loan Program

This program provides loans to assist in the development of essential community facilities in rural areas and towns of up to 20,000 people. Grants are awarded on a graduated scale; small communities with low population and income will receive a higher percentage of grants. Program monies can be used to assist in the development of essential community facilities such as constructing, enlarging, or improving community facilities for healthcare, public safety, or public and community services (such as the construction of a new building to house and display museum items). Requests can include the purchase of equipment required for a facility’s operation.

USDA Rural Development Community Facility Grant Program – Disaster Recovery Program

This program provides grants to assist in the development of essential community facilities in rural areas and towns of up to 20,000 people. A maximum of $50,000 grants are awarded on a graduated scale; based on the community’s Median Household Income. According to the American Community Survey 5- Year Estimate (2006-2010), the Village’s Median Household Income is $19,821, making the Village eligible for a maximum grant rate of 75%.

6.05 ACTION ITEMS Following completion of this study there are several key steps to take for the Village to move a project into the implementation phase. A few of these steps, generally in order, are as follows:

1) Continue to communicate and educate the community on the need for the project to protect the public, health, and safety of the Village of North Loup by providing outreach information to the public and posting information on the LLNRD Facebook, website, Greeley Citizen, and Ord Quiz. 2) Coordinate with LLNRD to apply for WFPO funding through the NRCS by July 31, 2020, to establish the Mira Creek Watershed WFPO Plan and Environmental Assessment. 3) Further evaluate geotechnical, hydraulic, and hydrogeologic conditions for the large dam to determine the site suitability, construction feasibility, detailed dam and pool size, and likelihood of groundwater recharge. 4) The Village should complete a detailed engineering assessment of interior drainage issues and solutions. This would include a detailed survey of all interior drainage structures and pathways within North Loup.

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5) The Village should consider basic interior drainage improvements in-house, such as ditch cleanouts and culvert replacements.

6.06 DISCLAIMER This study looked at the potential maximum flood control benefits of various structural alternatives. Detailed designs of these alternatives were not performed. Each alternative would require individual H&H design, geotechnical evaluation, environmental assessment, and survey. The proposed flood reduction benefits of the alternatives could be reduced in the process of a detailed design. JEO Consulting Group Inc. does not guarantee the feasibility of any alternative without a detailed engineering evaluation.

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CHAPTER 7. COMMUNITY ENGAGEMENT A 25-member stakeholder committee was established at the initiation of the study process (Table 7) that included LLNRD, JEO, and a diverse group of local stakeholders and property owners. The stakeholder committee was responsible for review and served as local contacts to residents to provide information during the study process.

Table 7: North Loup Stakeholder Committee Name Agency Name Agency Bob Sevenker Valley Co Jake Miriovsky JEO John DeRiso Valley Co Jon Mohr JEO Jay Meyer Valley Co Jerry Marshall Village of North Loup Pat Waldman Valley Co Daryl Jorgensen North Loup Vol. Fire Dept Kathy Waldman Citizen Randy Wadas First Responders/property owner Carrie Hansen Village of North Loup Scott Philbrick Valley County EM Jim Goodrich Village of North Loup Alma Beland Region 26 EM Heath Birkel Village of North Loup Duane Jacobs Citizen Amos Lange North Loup Irrigation District Sue Jacobs Citizen Russ Callan Lower Loup NRD Dalen Koehn Citizen Tylr Naprstek Lower Loup NRD Linda Markvicka Citizen/Librarian Brian Kolar Lower Loup NRD Rick Vlach LLNRD Monte Jorgensen Citizen

A series of meetings were held throughout the development of this project, as well as a public response period to offer residents and property owners an opportunity to voice their opinions and ask any questions about the project findings. Below is a summary of the types and dates of meetings. Sign-in sheets, public notification materials, and public comments are located in Appendix C. Note that meetings after March 2020 were held virtually due to governmental restrictions on public gatherings during the COVID-19 pandemic.

Kickoff Meeting: 1/30/2020

LLNRD staff met with JEO to discuss the scope of the project, data collection efforts, schedule, and final deliverables.

Small Group Meeting: 2/4/2020

LLNRD staff, Valley County representatives, and Village Board and staff representatives met with JEO to discuss the study process, problem areas, and brainstorm preferred solutions.

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Stakeholder Meeting: 2/4/2020

The larger group, attended by multiple property owners near Mira Creek, discussed their responsibilities, study progress and schedule, data collection efforts, issues and ideas about the development of the project, and the goals and objectives of the project.

NRD Committee Meeting: 4/14/2020

The Program/Projects Committee were provided a presentation using GoToMeeting by JEO’s project manager and project engineer. The presentation focused on the alternatives assessment, groundwater evaluation, preferred alternative recommendation, cost opinion, and actions items.

Public Response Period: 4/17/2020 – 5/8/2020

In lieu of a public Open House, a presentation describing the study’s purpose, benefits, and cost was created by JEO’s project engineers and placed on YouTube. The presentation was advertised in the Greeley Citizen, Ord’s Quiz Composition, LLNRD’s Facebook and website, and through flyers hung around the community. A total of 16 public comments were received through phone calls and emails along with a total of 273 views on the YouTube video as of 5/19/2020.

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CHAPTER 8. REFERENCES Lower Loup Natural Resources District (LLNRD), 2017. Lower Loup NRD Multi-Jurisdictional Hazard Mitigation Plan. Published June 2017.

LRE Water, 2020. Mira Creek Preliminary Desktop Hydrogeologic Assessment. Published April 13, 2020.

Nebraska Department of Natural Resources, (NeDNR) 2019. Mira Creek near North Loup, Nebraska 06788988. Retrieved from: https://nednr.nebraska.gov/RealTime/Stations/Details/06788988.

US Department of Agriculture (USDA), 2019. Cropland Data Layer-2009 & 2019 Published crop-specific data layers (Online), Washington D.C.: National Agricultural Statistic Service. Retrieved from: https://nassgeodata.gmu.edu/CropScape/.

US Department of Housing and Urban Development (HUD), 2020. FY 2020 ACS 5-Year 2011-2015 Low- and Moderate-Income Summary Data. Retrieved from: https://www.hudexchange.info/programs/acs-low-mod-summary-data/.

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APPENDIX A: MIRA CREEK HYDROGEOLOGIC ASSESSMENT

LRE WATER MEMORANDUM - APRIL 13TH, 2020

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Memorandum

To: Jon Mohr – JEO Consulting Group, Inc. (JEO) From: Dave Hume, PG Copy to: Jake Miriovsky, JEO; Mike Plante, LRE

Date: April 13, 2020 Project: Mira Creek Assessment – Lower Loup Natural Resource District (LLNRD) Subject: Preliminary Desktop Hydrogeologic Assessment

Purpose

The purpose of this memorandum is to provide JEO with the results of LRE Water’s (LRE) preliminary desktop assessment (Assessment) to assist with JEO’s evaluation of six surface water retarding structures in the Mira Creek watershed (watershed) of the LLNRD. The purpose of the structures is to help control flooding and reduce the risk in the Village of North Loup (Village), which is located near the confluence of Mira Creek and North Loup River.

The Assessment was completed to better understand the hydrogeology in the vicinity of each structure and to evaluate the likelihood for the structures to potentially recharge the underlying principal aquifer as a result of leakage or infiltration. The Assessment will also help JEO and LLNRD decide between “dry” and traditional “wet” dams for the flood control and associated recreational purposes. The Assessment is based on currently available information and is only meant to provide very preliminary qualitative results. Structure site-specific field investigations and testing will be required before any final designs.

Tasks

LRE completed the following tasks as part of the Assessment:

• Used NDNR well logs and UNL CSD test hole data to complete a GIS-based desktop assessment and hydrogeological assessment focused near the proposed structures, referred to by JEO as Dry Dam 6, Dry Dam 5, Dry Dam 2, Detention Cells, Diversion Channel, and the Big Dam, with a focus on the Big Dam.

• Provided a general assessment though the watershed, to gather data to gain a better understanding of the hydrostratigraphy, groundwater levels and trends, and hydraulically connected groundwater and surface waters.

• Identified and mapped the extent and thickness of the principal aquifer, major confining or semi-confining layers, and any potential perched groundwater systems.

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• Mapped the depth to the uppermost potentiometric or water table surfaces.

• Created the water table and potentiometric surface contour map to determine groundwater flow direction and gradients across the watershed.

• Created hydrogeologic cross sections showing the major hydrostratigraphic units and the potentiometric or water table surface measured in wells at the time of installation.

Assessment Location

• The watershed and locations of the possible structures are shown on Figure 1. The watershed lies in the dissected loess plains and alluvial valley topographic regions of Nebraska. The major streams are the North and South branches of Mira Creek that converge just west of the Village.

Hydrogeologic Conditions

• Mira Creek and its tributaries and canals drain the watershed to the North Loup River. Based on the USGS National Hydrography Dataset, all the streams and canals are intermittent except for the lower portion of the North Loup River and the North and South Branches of Mira Creek as shown on Figure 1. The portions that are perennial are classified as perennial meaning they obtain the majority of their flow under normal conditions from groundwater discharge from the principal aquifer (Figure 1). Because of the rise in groundwater levels that have been occurring in the area since the early 1980s there are likely other perennial streams not shown on Figure 1

• Perched groundwater may also contribute to stream flow; however, there is currently no data to identify perched systems across the watershed and near the structures.

• The primary geologic units present below the watershed include Quaternary-age clay, loess, and fine- grained sands underlying the dissected plains, and Quaternary-age alluvial silt, sand, and gravel in the alluvial valleys The Quaternary deposits are underlain by the Tertiary-age Ogallala Group, which consists of unconsolidated silt, sand, and gravel, and semi- to consolidated sandstones, siltstones and some limestones. The Ogallala makes up the majority of the High Plains aquifer and is the principal aquifer in the watershed.

• Four hydrogeologic cross sections were created through the structures. The locations of the transects A-A’ through D-D’ shown on Figure 1, and the cross sections are shown on Figures 2 and 3. The cross sections show the hydrostratigraphy and potentiometric surface when the well was installed. The cross sections show the following major stratigraphic units, from top to bottom (where present). These are provided in more detail in Table 1 for each structure.

o Topsoil-clay-silt (low-permeable confining unit)

o Sandy clay (moderate-permeable leaky confining unit)

Jon Mohr April 13, 2020 Page 3 of 5

o Sands and gravels and Ogallala (high-permeable aquifer)

• The principal aquifer can be under water table, semi-confined (i.e., leaky), or confined conditions. Based on the hydrogeologic cross section, the principal aquifer in the watershed is mostly confined and semi- confined. The type of aquifer under each structure is listed in Table 1. The aquifer type was determined by comparing the depth to the water level in a well at the time of installation relative to the stratigraphy. If the water level in a well screened in the Ogallala or a sand and gravel aquifer rises above the top of the aquifer, and the aquifer is overlain by clay and silt, the aquifer is under pressure or confined (i.e., a low-permeable confining unit). If the aquifer is overlain by sandy clay (i.e., moderate-permeable leaky confining unit) the aquifer is semi-confined or leaky. The imaginary water level surface for a confined or a semi-confined aquifer is referred to as the potentiometric surface. There may be places where the principal aquifer is also under water table conditions or atmospheric pressure if no confining or semi confining units overly the aquifer.

• The potentiometric surface of the principal aquifer across the watershed is shown on Figure 4. The surface was determined by subtracting the interpolated depth to water surface from water level measurements made at the time of well installation from the DEM surface. Groundwater generally flows from upland areas toward Mira Creek and the North Loup River where it discharges.

• Groundwater levels across the watershed have increased since predevelopment from approximate 5 to 50 feet based on published maps by DNR. This is shown Figure 5. Water level data from three observation wells in the watershed from the LLNRD are shown as well hydrographs on Figure 6. These confirm the CSD’s map showing water levels in the loess plains (Wells No. G042395 and G020710) have increased as much as 30 to 40 feet since the mid-1970s. Level in G014763 located in the North Loup valley have remained relatively stable. The rise in water levels suggests that the potentiometric surface at the time of installation shown on Figure 4 and on cross section in Figures 2 and 3 is likely higher.

• Figure 7 illustrates the estimated depth to groundwater below grade across the watershed. Depth to groundwater is approximate and was determined by subtracting the interpolated potentiometric surface on Figure 5 from the DEM surface. Table 1 shows the shallowest depth to groundwater for each structure based on Figure 7. It also includes the additional rise in groundwater levels that could potentially be at each structure based on the DNR’s map in Figure 5.

• Table 1 also includes a Relative Potential for Infiltration and Groundwater Recharge ranking. This ranking is a qualitative assessment of each structure's potential to lose water to groundwater by infiltration. It is based on the thickness of the low-permeable clay and silt zone that underlies each structure. Structures with less or no clay and silt have a greater potential to lose water to the principal aquifer. It also considers the depth to the potentiometric surface and if the unit overlying the principal aquifer is confining or semi- confining. This also assumes the water level in the structure remains higher than the groundwater level creating an induced recharge condition. Note that if the water level in structure falls below the level of the groundwater level, there is potential for the structure to gain or fill with groundwater.

Jon Mohr April 13, 2020 Page 4 of 5

Data Gaps and Recommendations

• The Assessment results are based on currently available information outlined above. As shown on Figure 1, site-specific hydrogeologic data are very limited or absent in the area of each structure. Therefore, information on the hydrostratigraphic layers, depths to current groundwater levels, and possible perched water zones that could affect infiltration and potential groundwater recharge are uncertain. To address these uncertainties, site-specific investigation activities are recommended for each of the structure(s) that are selected by JEO and the LLNRD for further evaluation. The activities should include, but not limited to the following:

o Develop a subsurface investigation work plan and select locations for test hole drilling, piezometer installation, groundwater level monitoring, hydraulic conductivity testing, and the necessary geotechnical work required by JEO;

o Implement the work plan to characterize the thickness, hydraulic properties, and types of unconsolidated materials down to the top of the Ogallala;

o Install pairs of nested piezometers around each structure to determine the depths to groundwater, peached ground water zones, if present, and measure the vertical and horizontal hydraulic gradients;

o Collect necessary geotechnical information that can be used to estimate infiltration rates; and,

o Prepare site-specific geotechnical and hydrogeologic assessment reports.

Reference

CONSERVATION AND SURVEY DIVISION, 2016. Groundwater-Level Changes in Nebraska - Predevelopment to Spring 2016 (http://snr.unl.edu/csd) School of Natural Resources (http://snr.unl.edu) Institute of Agriculture and Natural Resources University of Nebraska-Lincoln.

Table 1 Summary of Hydrogeology and Qualitative Recharge Potential at Proposed Flood Control Structures Mira Creek Flood Control Structure Assessment Lower Loup NRD

DNR GW Shallowest Change Pre- Relative Geology to Top of Depth to top Stream Depth to GW Total Thickness of Dev to 2018 Potential for Structure Ogallala of Ogallala Aquifer Type Perennial at based on clay/silt (ft) based on Infiltration and (ft bg) (ft bg) Structure Figure 7 Figure 5 GW Recharge (ft bg) (ft bg) No 0 (however, ~75 Dam 2 Sandy clay (0-~75) (although likely leaky-confined potential as 20-30 11 High (to Ogallala) Sandy clay 0-~75) shown on cross section) ~55 Topsoil & clay (0-~45) (to sand) Sandy clay (~45-~55) Dam 5 ~45 leaky-confined No 20-30 33 Low Sand (~55-~65) ~75 Sandy clay (~65-~75) (to Ogallala) ~30 - ~55 (to Ogallala; Topsoil & clay (0-~20) Ogallala Dam 6 Sandy clay (~20-~55 ~20 appears leaky-confined No 10-20 15 Moderate variable) shallowest at south end of dam reservoir) ~20 Topsoil & clay (0-~2) ~2 (to sand) Big Dam Sandy clay (~2-~20) (then sandy clay leaky-confined Yes 20-30 2 High Sand (~20-~35) ~2-~20) ~35 (to Ogallala) Yes Confined Detention ~35 (however, not Topsoil & clay (0-~35) ~35 (due to clay over 20-30 19 Low Cells (to Ogallala) evident on the Ogallala) cross section) ~15 However, shallow ~15 (to sand Transitional Topsoil & clay (0-~15) well logs east of well and gravel) Confined to Diversion Sand (~15-~30) ID 105720 indicate Unconfined, likely Yes 5-20 <0 High Channel Clay (~30-~43) ~5 ft of sand at ~45 pending Mira Sand (~43-~45) grade, then sand (to Ogallala) Creek stage level >~10 ft bg

Notes: - ft: feet - ft bg: feet below grade

Depth to groundwater is approximate and was determined by subtracting the interpolated potentiometric surface created from water level measurements at the time of well installation from the DEM surface.

Relative Potential for Infiltration and Groundwater Recharge ranking. This ranking is a qualitative assessment of each structure's potential to lose water to groundwater by infiltration. It is based on the thickness of the low-permeable clay and silt zone that underlies each structure. Structures with less clay and silt have a greater potential to lose water to the principal aquifer. It also takes into account the depth to the potentiometric surface and if the unit overlying the principal aquifer is confining or leaky. This also assumes the water level in the structure remains higher than the groundwater level creating an induced recharge condition. Note that if the water level in structure falls below the level of the groundwater level, there is potential for the structure to gain or fill with groundwater. >! Well >! Well on Cross Section (labeled with well ID number) *# >! LLNRD Monitoring Well >! >! (labeled with well registration number) >! >! >! *# UNL-CSD Test Hole >! >! *# >! >! >! *# UNL-CSD Test Hole on Cross Section >! >! >! >! U¬ Mira Creek Gaging Station ! >! >>! A >! ! ! *# Mira Creek Watershed >!> ! >! > >! >! > >!199391 >! >! >! >! >! >! Hydrogeologic Cross-Section >! >! >! >! Transect >! >! >! >! >! >! *# *# >!135491>! B NHD Stream >! >! >! >! >!30953 NHD Perennial Stream >! >! >! >! >! Dam 2 >! >! >! *#>! *# >! >! >! >! 125350>! 91263 >! ! >! >! >! >! *# >!> ! >! >! >! >!> >! A' 44217 D C >! >! >! >! 242518 >! !>184462 >! >!>! *# >! >! >! >! > >! ! >! G-020710 >! >! >! >! >! >! >! > >! 126928 >! >! >! Big Dam >! >! >! >!>! >!>! G-014763 >!>! >! >! >! >! B k 8932 >! rth ra a C e 70361 !> >! >! >! >! >! !o n Mir r>!e >! >>! >! *# >! >! >! N> ch >! 199069>! >! Dam 6 >! >! Dam 5 >! Diversion >! >! 120699 >! >! U¬ *# Channel >! >! >! >! ! >! >! >! >! 29-B-43 >! ± >! >! > >! >! >! 257987 >!>!>!>!>!>!!>! !!>!>!>!>!>!>!>!>!D' >! >! *# >! 105720>!>! >!>!>!>! >!>!>! >! *#>! 0 2 >! >! >! >! >! 35290 108448 >! >! >! >! >! >! Detention ! ! >! >! > Miles >! > >! 26-B-43 *# >!68161 Cells >! >! >! >! ! >! >! >! >! >! >! >! > >! >! >! >! >! >! ! Notes: >! >! >! 245565 >! > ! >!>! >! >! >! >! >! >! >! >! >! >! *# 22201 >! >! B' 27-B-43 >! Only wells or test holes on cross section lines are labeled. >! k >! >! >!Sou >!ree >! >! 28928 th Branch>!Mira C >! >! >! *# >! >! >! >! Sources: >! >! >! >! >! >! >! >! >! >! 64634 >! ! C' Service Layer Credits: Copyright:© 2013 National Geographic > >! >! >! >! G-042395>! *# Society, i-cubed >! >! >! *# >! *# >! >! >! Well and Test Hole Locations: Nebraska Department of >! >! >! Natural Resources All Wells Database, and University of Nebraska-Lincoln Conservation Survey Division Test Hole Database. >! >!

Prepared By: JEO CONSULTING GROUP LRE Water MIRA CREEK FLOOD PREVENTION STUDY Innovative Water Resource Solutions ORD, NEBRASKA " 1221 Auraria Parkway HYDROGEOLOGIC CROSS-SECTION TRANSECTS Denver, Colorado 80204 (303) 455-9589 FILE: JEO_MiraCreek01a.MXD DATE: 4/1/2020 FIGURE: 1 F:\GIS\GIS\JEO_Mira_Creek\maps\JEO_MiraCreek01a.mxd, 4/1/2020,Zone UTM F:\GIS\GIS\JEO_Mira_Creek\maps\JEO_MiraCreek01a.mxd,NAD 1983 PM, 14N2:49:02 North A A' B Branch B' North Dam 2 South North Mira Creek South 91263

2200 2200 D-D' Dam 5

135491 Big 2150 2150 2150 Dam 2150 199391 44217 125350 30953 2100 2100 2100 2100 é+ 26-B-43 126928 27-B-43 é (6/6/94) 35290 + 68161 (9/19/01) é+ 2050 (4/15/00) 2050 2050 2050 é+ é+ (7/6/09) (7/22/68) (7/17/00) é+ (6/15/78) (10/20/67) 2000 2000 2000 é+ é+ 2000 (6/5/65) é+ Elevation (feet) Elevation (feet) Elevation (feet) 1950 1950 Elevation (feet) 1950 1950

1900 1900 1900 1900

1850 1850 1850 1850

1800 1800 1800 1800

1750 1750 1750 1750

1700 1700 1700 1700

1650 1650 0 8,000 Feet 50x vertical exaggeration 1550 1550 Geologic Contact (all contacts are inferred) Well ID Number

Clay, Silt, and Topsoil 64634 Sources: # Potentiometric Surface USGS Valley Co. 30-meter DEM. Sandy Clay (Measured at Installation Date) Screen Well and Test Hole Locations: Nebraska Department of Natural Resources All Wells Database, and Sand and gravel or Ogallala (Undifferentiated) University of Nebraska-Lincoln Conservation Survey Division Test Hole Database.

Ogallala - primarily consolidated to semi-consolidated Cross Section Transects: Digitized and snapped to well or test hole locations. sandstone, siltstone, and limestone with some sands and gravels (Undifferentiated) Grade Profile: Extracted from 30-meter DEM.

Prepared By: JEO CONSULTING GROUP LRE Water MIRA CREEK FLOOD PREVENTION STUDY Innovative Water Resource Solutions NORTH LOUP, NEBRASKA " 1221 Auraria Parkway HYDROGEOLOGIC CROSS SECTIONS A-A' & B-B' Denver, Colorado 80204 (303) 455-9589 FILE: JEO_MiraCreek01b_xsect_A&B.MXD DATE: 4/9/2020 FIGURE: 2 F:\GIS\GIS\JEO_Mira_Creek\maps\JEO_MiraCreek01b_xsect_A&B.mxd, 5:44:53 4/9/2020,F:\GIS\GIS\JEO_Mira_Creek\maps\JEO_MiraCreek01b_xsect_A&B.mxd, StatePlane Nebraska Feet NAD 1983 2600PM, FIPS C C' D D' South North South West North East D-D' Branch Branch Mira Creek Mira Creek B-B' C-C'

184462 North 2150 Branch 2150 Dam 6 Mira Creek Dam 6 Big 2100 Detention 2100 2100 Mira Creek 2100

120699 Dam

Cells 242518 Diversion 28928 126928 120699 Channel 64634 2050 2050 2050 70361 2050 22201 257987 (4/20/07) 245565 é+ (2/7/57) (11/9/63) é+(7/17/00)

8932 2000 2000 2000 2000 29-B-43 é+ é+ (9/29/99) 199069 é+ é+(5/16/79) é+ (9/29/99) é (10/21/08)

+ 105720 (10/31/16) (5/10/77) é(4/4/16) é+ 108448 (8/2/19) + é

(1/30/56) + Elevation Elevation (feet) Elevation (feet) Elevation (feet) 1950 é+ 1950 1950 é 1950 é+ + (6/20/97) 1900 1900 1900 1900

1850 1850 1850 1850

1800 1800 1800 1800

1750 1750 1750 1750

1700 1700 1700 1700

1650 1650 0 8,000 Feet 50x vertical exaggeration

Geologic Contact (all contacts are inferred) Well ID Number

Clay, Silt, and Topsoil 64634 Sources: # Potentiometric Surface USGS Valley Co. 30-meter DEM. Sandy Clay (Measured at Installation Date) Screen Well and Test Hole Locations: Nebraska Department of Natural Resources All Wells Database, and Sand and gravel or Ogallala (Undifferentiated) University of Nebraska-Lincoln Conservation Survey Division Test Hole Database.

Ogallala - primarily consolidated to semi-consolidated Cross Section Transects: Digitized and snapped to well or test hole locations. sandstone, siltstone, and limestone with some sands and gravels (Undifferentiated) Grade Profile: Extracted from 30-meter DEM.

Prepared By: JEO CONSULTING GROUP LRE Water MIRA CREEK FLOOD PREVENTION STUDY Innovative Water Resource Solutions NORTH LOUP, NEBRASKA " 1221 Auraria Parkway HYDROGEOLOGIC CROSS SECTIONS C-C' & D-D' Denver, Colorado 80204 (303) 455-9589 FILE: JEO_MiraCreek01b_xsect_C&D.MXD DATE: 4/9/2020 FIGURE: 3 F:\GIS\GIS\JEO_Mira_Creek\maps\JEO_MiraCreek01b_xsect_C&D.mxd, 4/9/2020, StatePlaneNebraska F:\GIS\GIS\JEO_Mira_Creek\maps\JEO_MiraCreek01b_xsect_C&D.mxd, NAD 19832600 PM, 5:45:03 FIPS Feet >! Well with Water Level Data >! Well without Water Level Data 1960 1950 >! LLNRD Monitoring Well Diversion 1940 (labeled with well registration number) *# Channel *# UNL-CSD Test Hole % *# ¬U Mira Creek Gaging Station % 2040 Mira Creek Watershed >! >! ek >! >! Cre >!>! ira >! >!>!>! >! 2060 M >!>! Potentiometric Contour (feet) >! >!>!>!>! >!>!>!>!>! *# >! >! 1980 >!>!>!>!>!>! >!>! >! >!>!>!>!>!>!>! >! >! % Groundwater Flow Direction >! >! >!>!>! >>! >! >! NHD Stream >! >! >!>! >! ! NHD Perennial Stream >! > >! 0 3,000 >!>! >! *# Dam Alignment >! >! >! Feet >! >! >! >! 2000>! >! >! >! 2020 >! Potentiometric Surface (feet) >! ! >! >! >! High : 2173 >! >! > >! >! *# 2080 >! 2000 *# >! >! >! >! >! >! 2080 >! % 1980 1980 Low : 1917 >! 2060 >! >! >! >! Potentiometric Surface (feet) - Inset Only >! >! *#>! Dam 2 *# High : 1964 2100 >! >! >! >! >! 1980 >! >! ! >! >! >! > 1940 *# >! >! >! >! >! >!2080 >! % Low : 1933 Big Dam 1960 ! >! >! G-020710 >! >! >! >! >! >!>! *# >! > >! >! >! ! ! >! >! >! >! 2040 >! >! > > >! >! % >! >! >! C >! 2000 >! >! !>! >!>! ira re G-014763 >!>! 2120 > h M e >! >! >! >! nc k >! 2160 a >! >! >! >! >! Br>! >! Dam 6 >! >! *# >! >! >! >! >! North >! ± >! >! 2040 >! Dam 5 >! Diversion >! >! 0 2 % >! ¬U *# Channel >! 2080 >! >! >! >! >! >! >! Miles >! >! >! >! >! >!>!>! >! >! >! >!>!>!>!>!>!>!>!>!>!>! >! 2140>! *# >! 1980 >! >>>! >!>! >! *#>! >! >! >! >! >! 2020 >! >! >! >! >! >! Detention >! Notes: >! >! *# >! >!>! >! >! >! 1960 Cells >! >! >! >! >! >! >! Water levels are from the date of well installation. >! >! >!>! >! 2060 >! >! >! >! >! >! >! ! % >! k >! >!> >! >! *# >! e >! >! >! >! >! >! >! Cre 1960 >! >! ira Sources: >! ranch M >! ! >!B >! 2000 > >! S>!o ut h Service Layer Credits: Copyright:© 2013 National Geographic >! >! >! *# >! >! >! >! Society, i-cubed >! >! >! >! >! >! >! >! >!>! 2100 >! >! >! Well and Test Hole Locations: Nebraska Department of >! >! >! G-042395>! *# >! >! >! Natural Resources All Wells Database, and University of *# >! *# >! >! >! 1980 Nebraska-Lincoln Conservation Survey Division Test Hole >! 2040 Database. >! >! 2000 2080 2020 NHD streams and perennial streams. >! >! 30-meter USGS DEM for ground elevation reference. Prepared By: JEO CONSULTING GROUP LRE Water MIRA CREEK FLOOD PREVENTION STUDY Innovative Water Resource Solutions ORD, NEBRASKA " 1221 Auraria Parkway GROUNDWATER POTENTIOMETRIC SURFACE WITH Denver, Colorado 80204 WATER LEVELS MEASURED ON DATE OF INSTALLATION (303) 455-9589 FILE: JEO_MiraCreek01c_welev_inset.MXD DATE: 5/20/2020 FIGURE: 4 E:\GIS\GIS\JEO_Mira_Creek\maps\JEO_MiraCreek01c_welev_inset.mxd, 5/20/2020, NAD1983PM,4:05:28 Zone UTM 14N >! LLNRD Monitoring Well (labeled with well registration number) U¬ Mira Creek Gaging Station Diversion Channel Mira Creek Watershed NHD Stream ek NHD Perennial Stream Cre ira M Potentiometric Change Map (Predevelopment to 2016) 5 - 10 10 - 20 0 3,000 20 - 30 Feet 30 - 40 40 - 50 50 - 60

Dam 2

G-020710>! Big Dam

ira Cr G-014763 h M ee nc k >! Bra North ± Dam 6 Dam 5 Diversion 0 2 U¬ Channel Miles Detention Notes: Cells

Change map georeferenced from JEO figure. k re e a C Sources: anch Mir Br So ut h Service Layer Credits: Copyright:© 2013 National Geographic Society, i-cubed

NHD streams and perennial streams. G-042395>!

Water Level change map is Pre-Development to 2016. CONSERVATION AND SURVEY DIVISION, 2016. Groundwater-Level Changes in Nebraska - Predevelopment to Spring 2016 (http://snr.unl.edu/csd)

Prepared By: JEO CONSULTING GROUP LRE Water MIRA CREEK FLOOD PREVENTION STUDY Innovative Water Resource Solutions ORD, NEBRASKA " 1221 Auraria Parkway POTENTIOMETRIC ELEVATION CHANGE Denver, Colorado 80204 PREDEVELOPMENT TO 2016 (303) 455-9589 FILE: JEO_MiraCreek01c_welev_change.MXD DATE: 4/2/2020 FIGURE: 5 F:\GIS\GIS\JEO_Mira_Creek\maps\JEO_MiraCreek01c_welev_change.mxd, 4/2/2020, 9:00:49 AM, NAD1983AM,14N Zone UTM 9:00:49F:\GIS\GIS\JEO_Mira_Creek\maps\JEO_MiraCreek01c_welev_change.mxd, 4/2/2020, Figure 6 Observation Wells G-042395, G-020710, and G-014763 Hydrographs Mira Creek Flood Control Structure Assessment Lower Loup NRD 0

10

20

30

40 G014763

50 G042395 Water Level (feet below grade) G020710 60

70 6/11/1968 8/28/1976 11/14/1984 1/31/1993 4/19/2001 7/6/2009 9/22/2017 12/9/2025 Date >! Well with Water Level Data >! Well without Water Level Data Diversion >! LLNRD Monitoring Well *# Channel (labeled with well registration number) *# UNL-CSD Test Hole *#

U¬ Mira Creek Gaging Station >! >! k >! ree >! ra C >! Mira Creek Watershed >!>! i >!>!>!>! >! >! M >!>!>!>! >!>!>!! *# >! >! >!>!>!>!>!>! >!>!>!> >! >!>!>!>!>!>!>! >! >! NHD Stream >! >! >!>!>! >>! >! >! >! >!>! >! NHD Perennial Stream >! ! >! > >! 0 3,000 >!>! >! *# Depth to Potentiometric Surface >! >! >! Feet >! ! >! (feet below grade) >! >! >! > >! >! >! >! at grade >! >! >! >! >! >! >! >! *# 0 - 10 >! *# >! >! 10 - 20 >! >! >! >! 20 - 30 >! >! >! 30 - 40 >! >! Dam 2 >! 40 - 50 >! >! *#>! *# >! 50 - 75 >! >! >! ! > >! >! >75 *# >! >! >! >! >! >! >!>! >! >! >! >! >! >! >! >! >! >!>! *# >! >! >! >! >! ! >! G-020710 >! Big Dam >! >! >! >! >! >! > >! >! >! >! C >! >! >! >!>! >!>! ira re G-014763 >!>! >! >! >! >! h M e >! anc k >! >! >! >! >! Br>! >! >! >! *# >! >! >! >! >! North >! ± >! >! Dam 6 >! Dam 5 >! Diversion >! >! 0 2 >! U¬ *# Channel >! >! >! >! >! >! >! >! >! >! >! >! >! Miles >! >! >! !!>!>!!>>!>!>!>!>!>!>! >! >! *# >! >!>! >!>!>!>! >!>! >! *#>! >! >! >! >! >! >! >! >! >! >! >! Detention ! ! >! >! > Notes: >! > >! *# >! Cells >! >! >! >! >! >! >! >! >! Water levels are from the date of well installation. >! >! >!>! >! >! >! >! >! >! >! >! >! >! k !>! >! >! e >! >! >! >! >!> >! *# re >! >! >! >! ra C Sources: >! >! ranch Mi ! >!B >! >! > >! S>!o ut h Service Layer Credits: Copyright:© 2013 National Geographic >! >! >! *# >! >! >! >! Society, i-cubed >! >! >! >! >! >! >! >! >!>! >! >! >! Well and Test Hole Locations: Nebraska Department of >! >! >! G-042395>! *# >! >! >! Natural Resources All Wells Database, and University of *# >! *# >! >! >! Nebraska-Lincoln Conservation Survey Division Test Hole >! Database. >! >!

NHD streams and perennial streams. >! >! 30-meter USGS DEM for ground elevation reference. Prepared By: JEO CONSULTING GROUP LRE Water MIRA CREEK FLOOD PREVENTION STUDY Innovative Water Resource Solutions ORD, NEBRASKA " 1221 Auraria Parkway DEPTH TO POTENTIOMETRIC SURFACE FROM GRADE Denver, Colorado 80204 (303) 455-9589 FILE: JEO_MiraCreek01c_welev_inset_ftbg.MXD DATE: 4/2/2020 FIGURE: 7 F:\GIS\GIS\JEO_Mira_Creek\maps\JEO_MiraCreek01c_welev_inset_ftbg.mxd, 4/2/2020, 8:31:40 AM, NAD 1983 UTM Zone UTM NAD 1983AM, 14N 4/2/2020, F:\GIS\GIS\JEO_Mira_Creek\maps\JEO_MiraCreek01c_welev_inset_ftbg.mxd, 8:31:40 North Loup Flood Reduction Study Lower Loup Natural Resources District

APPENDIX B: DETAILED COST OPINIONS

SMALL DAM 2

SMALL DAM 5

SMALL DAM 6

LARGE DAM 1

LARGE DAM 2

MIRA CREEK BERM

SMALL BYPASS CHANNEL

LARGE BYPASS CHANNEL

DETENTION BASIN

JEO CONSULTING GROUP INC 40 ENGINEER'S CONCEPTUAL OPINION OF COST DAM 2 LOWER LOUP NRD NORTH LOUP DRAINAGE STUDY JEO PROJECT NO. 191310.00 ESTIMATE OF QUANTITIES Item # Description Unit Quantity Unit Price Total 1. Mobilization, Insurance & Bonding LS 1 $19,000.00 $19,000.00 2. Clearing and Grubbing AC 0.1 $7,000.00 $1,000.00 3. Stripping and Topsoiling CY 2,500 $4.00 $10,000.00 4. Dam Embankment (Onsite Material) CY 28,600 $4.00 $115,000.00 5. Principle Spillway - Slotted Riser EA 1 $5,000.00 $5,000.00 6. Principle Spillway - Concrete Riser Base LS 1 $1,000.00 $1,000.00 7. Principle Spillway - Piping LF 200 $70.00 $14,000.00 8. Principle Spillway - Discharge Pipe Support EA 1 $3,000.00 $3,000.00 9. Principle Spillway - Sand Drain & Diaphragm LS 1 $3,500.00 $4,000.00 10. Riprap, Type B TON 150 $70.00 $11,000.00 11. Erosion Control LF 200 $5.00 $1,000.00 12. Seeding and Mulching AC 4.0 $4,000.00 $16,000.00

Subtotal of Construction: $200,000.00 Contingencies: 25% $50,000.00 Total Construction: $250,000.00

Engineering Survey, Design, Construction Admin: $50,000.00 Materials & Geotechnical Construction Testing: $8,000.00 Land Acquisition: AC 26.0 $10,000.00 $260,000.00 TOTAL PROJECT COST $568,000.00

JEO Consulting Group Inc.’s (JEO) Opinions of Probable Cost provided for herein are to be made on the basis of JEO’s experience and qualifications and represent JEO’s best judgment. However, since JEO has no control over the cost of labor, materials, equipment, or services furnished by others, or over the Contractor’s methods of determining prices, or over competitive bidding or market conditions, JEO cannot and does not guarantee that proposals, bids, or actual construction cost will not vary from Opinions of Probable Cost prepared by JEO.

Prepared 4/28/2020 ENGINEER'S CONCEPTUAL OPINION OF COST DAM 5 LOWER LOUP NRD NORTH LOUP DRAINAGE STUDY JEO PROJECT NO. 191310.00 ESTIMATE OF QUANTITIES Item # Description Unit Quantity Unit Price Total 1. Mobilization, Insurance & Bonding LS 1 $12,000.00 $12,000.00 2. Clearing and Grubbing AC 1 $7,000.00 $7,000.00 3. Stripping and Topsoiling CY 1,500 $4.00 $6,000.00 4. Dam Embankment (Onsite Material) CY 12,100 $4.00 $49,000.00 5. Principle Spillway - Slotted Riser EA 1 $5,000.00 $5,000.00 6. Principle Spillway - Concrete Riser Base LS 1 $1,000.00 $1,000.00 7. Principle Spillway - Piping LF 160 $70.00 $12,000.00 8. Principle Spillway - Discharge Pipe Support EA 1 $3,000.00 $3,000.00 9. Principle Spillway - Sand Drain & Diaphragm LS 1 $3,500.00 $4,000.00 10. Riprap, Type B TON 150 $70.00 $11,000.00 11. Erosion Control LF 200 $5.00 $1,000.00 12. Seeding and Mulching AC 3.0 $4,000.00 $12,000.00

Subtotal of Construction: $123,000.00 Contingencies: 25% $31,000.00 Total Construction: $154,000.00

Engineering Survey, Design, Construction Admin: $31,000.00 Materials & Geotechnical Construction Testing: $8,000.00 Land Acquisition: AC 21.0 $10,000.00 $210,000.00 TOTAL PROJECT COST $403,000.00

JEO Consulting Group Inc.’s (JEO) Opinions of Probable Cost provided for herein are to be made on the basis of JEO’s experience and qualifications and represent JEO’s best judgment. However, since JEO has no control over the cost of labor, materials, equipment, or services furnished by others, or over the Contractor’s methods of determining prices, or over competitive bidding or market conditions, JEO cannot and does not guarantee that proposals, bids, or actual construction cost will not vary from Opinions of Probable Cost prepared by JEO.

Prepared 4/28/2020 ENGINEER'S CONCEPTUAL OPINION OF COST DAM 6 LOWER LOUP NRD NORTH LOUP DRAINAGE STUDY JEO PROJECT NO. 191310.00 ESTIMATE OF QUANTITIES Item # Description Unit Quantity Unit Price Total 1. Mobilization, Insurance & Bonding LS 1 $11,000.00 $11,000.00 2. Clearing and Grubbing AC 0.1 $7,000.00 $1,000.00 3. Stripping and Topsoiling CY 2,000 $4.00 $8,000.00 4. Dam Embankment (Onsite Material) CY 12,800 $4.00 $52,000.00 5. Principle Spillway - Slotted Riser EA 1 $5,000.00 $5,000.00 6. Principle Spillway - Concrete Riser Base LS 1 $1,000.00 $1,000.00 7. Principle Spillway - Piping LF 200 $70.00 $14,000.00 8. Principle Spillway - Discharge Pipe Support EA 1 $3,000.00 $3,000.00 9. Principle Spillway - Sand Drain & Diaphragm LS 1 $3,500.00 $4,000.00 10. Riprap, Type B TON 100 $65.00 $7,000.00 11. Erosion Control LF 200 $5.00 $1,000.00 12. Seeding and Mulching AC 3.0 $4,000.00 $12,000.00

Subtotal of Construction: $119,000.00 Contingencies: 25% $30,000.00 Total Construction: $149,000.00

Engineering Survey, Design, Construction Admin: $30,000.00 Materials & Geotechnical Construction Testing: $8,000.00 Land Acquisition: AC 35.0 $10,000.00 $350,000.00 TOTAL PROJECT COST $537,000.00

JEO Consulting Group Inc.’s (JEO) Opinions of Probable Cost provided for herein are to be made on the basis of JEO’s experience and qualifications and represent JEO’s best judgment. However, since JEO has no control over the cost of labor, materials, equipment, or services furnished by others, or over the Contractor’s methods of determining prices, or over competitive bidding or market conditions, JEO cannot and does not guarantee that proposals, bids, or actual construction cost will not vary from Opinions of Probable Cost prepared by JEO.

Prepared 4/28/2020 ENGINEER'S CONCEPTUAL OPINION OF COST LARGE DAM 1 LOWER LOUP NRD NORTH LOUP DRAINAGE STUDY JEO PROJECT NO. 191310.00 ESTIMATE OF QUANTITIES Item # Description Unit Quantity Unit Price Total 1. Mobilization, Insurance & Bonding LS 1 $191,000.00 $191,000.00 2. Clearing and Grubbing AC 6 $7,000.00 $42,000.00 3. Stripping and Topsoiling CY 5,000 $4.00 $20,000.00 4. Dam Embankment (Onsite Material) CY 340,000 $3.50 $1,190,000.00 5. Principle Spillway - Concrete Riser EA 1 $25,000.00 $25,000.00 6. Principle Spillway - Piping LF 240 $200.00 $48,000.00 7. Principle Spillway - Discharge Pipe Support EA 1 $5,000.00 $5,000.00 8. Principle Spillway - Sand Drain & Diaphragm LS 1 $10,000.00 $10,000.00 10. Auxiliary Spillway LS 1 $200,000.00 $200,000.00 11. Other Appurtenences LS 1 $100,000.00 $100,000.00 12. Bank Protection LS 1 $100,000.00 $100,000.00 12. Drawdown Piping and Control LS 1 $8,000.00 $8,000.00 13. Trash Rack EA 1 $2,000.00 $2,000.00 14. Riprap, Type B TON 1,000 $70.00 $70,000.00 15. Erosion Control LS 1 $50,000.00 $50,000.00 16. Seeding and Mulching AC 10.0 $4,000.00 $40,000.00

Subtotal of Construction: $2,101,000.00 Contingencies: 25% $526,000.00 Total Construction: $2,627,000.00

Engineering Survey, Design, Construction Admin: $395,000.00 Materials & Geotechnical Construction Testing: $25,000.00 Land Acquisition: AC 410.0 $10,000.00 $4,100,000.00 TOTAL PROJECT COST $7,147,000.00

JEO Consulting Group Inc.’s (JEO) Opinions of Probable Cost provided for herein are to be made on the basis of JEO’s experience and qualifications and represent JEO’s best judgment. However, since JEO has no control over the cost of labor, materials, equipment, or services furnished by others, or over the Contractor’s methods of determining prices, or over competitive bidding or market conditions, JEO cannot and does not guarantee that proposals, bids, or actual construction cost will not vary from Opinions of Probable Cost prepared by JEO.

Prepared 4/28/2020 ENGINEER'S CONCEPTUAL OPINION OF COST BIG DAM 2 LOWER LOUP NRD NORTH LOUP DRAINAGE STUDY JEO PROJECT NO. 191310.00 ESTIMATE OF QUANTITIES Item # Description Unit Quantity Unit Price Total 1. Mobilization, Insurance & Bonding LS 1 $213,000.00 $213,000.00 2. Clearing and Grubbing AC 5 $7,000.00 $35,000.00 3. Stripping and Topsoiling CY 6,000 $4.00 $24,000.00 4. Dam Embankment (Onsite Material) CY 400,000 $3.50 $1,400,000.00 5. Principle Spillway - Concrete Riser EA 1 $25,000.00 $25,000.00 6. Principle Spillway - Piping LF 240 $200.00 $48,000.00 7. Principle Spillway - Discharge Pipe Support EA 1 $5,000.00 $5,000.00 8. Principle Spillway - Sand Drain & Diaphragm LS 1 $10,000.00 $10,000.00 10. Auxiliary Spillway LS 1 $200,000.00 $200,000.00 11. Other Appurtenences LS 1 $100,000.00 $100,000.00 12. Bank Protection LS 1 $100,000.00 $100,000.00 12. Drawdown Piping and Control LS 1 $8,000.00 $8,000.00 13. Trash Rack EA 1 $2,000.00 $2,000.00 14. Riprap, Type B TON 1,000 $70.00 $70,000.00 15. Erosion Control LS 1 $50,000.00 $50,000.00 16. Seeding and Mulching AC 12.0 $4,000.00 $48,000.00

Subtotal of Construction: $2,338,000.00 Contingencies: 25% $585,000.00 Total Construction: $2,923,000.00

Engineering Survey, Design, Construction Admin: $439,000.00 Materials & Geotechnical Construction Testing: $25,000.00 Land Acquisition: AC 415.0 $10,000.00 $4,150,000.00 TOTAL PROJECT COST $7,537,000.00

JEO Consulting Group Inc.’s (JEO) Opinions of Probable Cost provided for herein are to be made on the basis of JEO’s experience and qualifications and represent JEO’s best judgment. However, since JEO has no control over the cost of labor, materials, equipment, or services furnished by others, or over the Contractor’s methods of determining prices, or over competitive bidding or market conditions, JEO cannot and does not guarantee that proposals, bids, or actual construction cost will not vary from Opinions of Probable Cost prepared by JEO.

Prepared 4/28/2020 ENGINEER'S CONCEPTUAL OPINION OF COST MIRA CREEK BERM LOWER LOUP NRD NORTH LOUP DRAINAGE STUDY JEO PROJECT NO. 191310.00 ESTIMATE OF QUANTITIES Item # Description Unit Quantity Unit Price Total 1. Mobilization, Insurance & Bonding LS 1 $38,000.00 $38,000.00 2. Clearing and Grubbing AC 6 $7,000.00 $42,000.00 3. Stripping and Topsoiling CY 3,000 $4.00 $12,000.00 4. Berm Embankment (Off-Site Material) CY 25,800 $8.00 $207,000.00 5. Interior Drainage Pipe, 18" LF 120 $80.00 $10,000.00 6. Interior Drainage Discharge Flap Gates/Outfall Structures EA 3 $5,000.00 $15,000.00 7. Roadway Crossings EA 2 $10,000.00 $20,000.00 8. Erosion Control LF 6,300 $5.00 $32,000.00 9. Seeding and Mulching AC 10.0 $4,000.00 $40,000.00

Subtotal of Construction: $416,000.00 Contingencies: 25% $104,000.00 Total Construction: $520,000.00

Engineering Survey, Design, Construction Admin: $130,000.00 Materials & Geotechnical Construction Testing: $30,000.00 Land Acquisition - Residential: LS 1.0 $500,000.00 $500,000.00 Land Acquisition - Agricultural: AC 16.0 $10,000.00 $160,000.00 TOTAL PROJECT COST $1,340,000.00

JEO Consulting Group Inc.’s (JEO) Opinions of Probable Cost provided for herein are to be made on the basis of JEO’s experience and qualifications and represent JEO’s best judgment. However, since JEO has no control over the cost of labor, materials, equipment, or services furnished by others, or over the Contractor’s methods of determining prices, or over competitive bidding or market conditions, JEO cannot and does not guarantee that proposals, bids, or actual construction cost will not vary from Opinions of Probable Cost prepared by JEO.

Prepared 4/28/2020 ENGINEER'S CONCEPTUAL OPINION OF COST DIVERSION CHANNEL LOWER LOUP NRD NORTH LOUP DRAINAGE STUDY JEO PROJECT NO. 191310.00 ESTIMATE OF QUANTITIES Item # Description Unit Quantity Unit Price Total 1. Mobilization, Insurance & Bonding LS 1 $29,000.00 $29,000.00 2. Clearing and Grubbing AC 1 $7,000.00 $4,000.00 3. Stripping and Topsoiling CY 5,000 $4.00 $20,000.00 4. Excavation (Disposed Off-Site) CY 35,200 $6.00 $212,000.00 5. Erosion Control LF 5,000 $5.00 $25,000.00 6. Seeding and Mulching AC 6.0 $4,000.00 $24,000.00

Subtotal of Construction: $314,000.00 Contingencies: 25% $79,000.00 Total Construction: $393,000.00

Engineering Survey, Design, Construction Admin: $59,000.00 Materials & Geotechnical Construction Testing: $25,000.00 Land Acquisition - Agricultural: AC 10.0 $10,000.00 $100,000.00 TOTAL PROJECT COST $577,000.00

JEO Consulting Group Inc.’s (JEO) Opinions of Probable Cost provided for herein are to be made on the basis of JEO’s experience and qualifications and represent JEO’s best judgment. However, since JEO has no control over the cost of labor, materials, equipment, or services furnished by others, or over the Contractor’s methods of determining prices, or over competitive bidding or market conditions, JEO cannot and does not guarantee that proposals, bids, or actual construction cost will not vary from Opinions of Probable Cost prepared by JEO.

Prepared 4/28/2020 ENGINEER'S CONCEPTUAL OPINION OF COST LARGE DIVERSION CHANNEL LOWER LOUP NRD NORTH LOUP DRAINAGE STUDY JEO PROJECT NO. 191310.00 ESTIMATE OF QUANTITIES Item # Description Unit Quantity Unit Price Total 1. Mobilization, Insurance & Bonding LS 1 $979,000.00 $979,000.00 2. Clearing and Grubbing AC 1 $20,000.00 $10,000.00 3. Stripping and Topsoiling CY 40,300 $4.00 $162,000.00 4. Embankment/Excavation CY 180,000 $3.50 $630,000.00 5. Erosion Control LF 16,000 $5.00 $80,000.00 7. Seeding and Mulching AC 50 $4,000.00 $200,000.00 8. New Highway 11 Bridge LS 1 $3,200,000.00 $3,200,000.00 9. New Railroad Bridge LS 1 $1,500,000.00 $1,500,000.00 9. Country Road Bridge LS 2 $2,000,000.00 $4,000,000.00

Subtotal of Construction: $10,761,000.00 Contingencies: 25% $2,691,000.00 Total Construction: $13,452,000.00

Engineering Survey, Design, Construction Admin: $2,018,000.00 Materials & Geotechnical Construction Testing: $100,000.00 Land Acquisition - Agricultural: AC 50.0 $10,000.00 $500,000.00 TOTAL PROJECT COST $16,070,000.00

JEO Consulting Group Inc.’s (JEO) Opinions of Probable Cost provided for herein are to be made on the basis of JEO’s experience and qualifications and represent JEO’s best judgment. However, since JEO has no control over the cost of labor, materials, equipment, or services furnished by others, or over the Contractor’s methods of determining prices, or over competitive bidding or market conditions, JEO cannot and does not guarantee that proposals, bids, or actual construction cost will not vary from Opinions of Probable Cost prepared by JEO.

Prepared 4/28/2020 ENGINEER'S CONCEPTUAL OPINION OF COST DETENTION PONDS LOWER LOUP NRD NORTH LOUP DRAINAGE STUDY JEO PROJECT NO. 191310.00 ESTIMATE OF QUANTITIES Item # Description Unit Quantity Unit Price Total 1. Mobilization, Insurance & Bonding LS 1 $1,316,000.00 $1,316,000.00 2. Clearing and Grubbing AC 60 $7,000.00 $420,000.00 3. Excavation (Disposed Off-Site) CY 3,050,000 $4.00 $12,200,000.00 4. Discharge Piping LF 200 $200.00 $40,000.00 5. Outfall Structures EA 2 $50,000.00 $100,000.00 6. Erosion Control LS 1 $100,000.00 $100,000.00 7. Seeding and Mulching AC 150 $2,000.00 $300,000.00

Subtotal of Construction: $12,740,000.00 Contingencies: 25% $3,185,000.00 Total Construction: $15,925,000.00

Engineering Survey, Design, Construction Admin: $1,593,000.00 Materials & Geotechnical Construction Testing: $100,000.00 Land Acquisition - Agricultural: AC 180.0 $10,000.00 $1,800,000.00 TOTAL PROJECT COST $19,418,000.00

JEO Consulting Group Inc.’s (JEO) Opinions of Probable Cost provided for herein are to be made on the basis of JEO’s experience and qualifications and represent JEO’s best judgment. However, since JEO has no control over the cost of labor, materials, equipment, or services furnished by others, or over the Contractor’s methods of determining prices, or over competitive bidding or market conditions, JEO cannot and does not guarantee that proposals, bids, or actual construction cost will not vary from Opinions of Probable Cost prepared by JEO.

Prepared 4/28/2020 North Loup Flood Reduction Study Lower Loup Natural Resources District

APPENDIX C: PUBLIC OUTREACH MATERIALS

MEETING ITEMS

• Kickoff Meeting Agenda – 1/3/2020 • Kickoff Meeting Notes • Small Group Meeting Sign-in Sheet – 2/4/2020 • Small Group Meeting Notes • Stakeholder Meeting Sign-in Sheet – 2/4/2020 • Stakeholder Meeting Notes • Public Presentation News Release – The Ord Quiz – 4/22/2020 • Public Comments – 5/12/2020

PROJECT HANDOUTS

• Overview Map • Project Summary • Preferred Alternatives Map

JEO CONSULTING GROUP INC 41

Meeting Agenda

DATE AND TIME | January 3, 2020 at 3:30pm PROJECT | LLNRD North Loup/Mira Creek Flood Prevention Study MEETING | Kick-off with JEO and LLNRD LOCATION | Conference call

Attendance: LLNRD – Russ Callen; Tylr Naprstek; Brian Kolar; JEO – Jake Miriovsky, Jon Mohr.

1. Scope of Services/Agreement a. Added the retainage statement

2. Schedule

3. Meetings a. Round One i. #1 Kickoff ii. #2 LLNRD and Village Representatives iii. #3 All Stakeholders

b. Round Two i. #4 Open House (switch from RFP) ii. #5 NRD Committee iii. #6 NRD Board

4. Data Collection a. Groundwater and stream data collection b. Site visit and walk stream same day as Meetings #2 and #3

5. Final Deliverable a. May 2019 following Board Presentation

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Meeting Notes (1-6-2020)

DATE AND TIME | January 3, 2020 at 3:30pm PROJECT | LLNRD North Loup/Mira Creek Flood Prevention Study MEETING | Kick-off with JEO and LLNRD LOCATION | Conference call

Attendance: LLNRD – Russ Callen; Tylr Naprstek; Brian Kolar; JEO – Jake Miriovsky, Jon Mohr.

1. Scope of Services/Agreement a. Added the retainage statement – The agreement was OK and has been executed.

2. Schedule – Aiming for a late-April completion, possibly early May depending on any final changes.

3. Meetings a. Round One i. #1 Kickoff – Complete 1-3-20, JEO can meet with the NRD again ahead of meeting #2, if needed. ii. #2 LLNRD and Village Representatives – Will include Valley County, scheduled for February 4th at 3pm. iii. #3 All Stakeholders – scheduled for February 4th at 6pm. JEO will provide dinner for NRD.

b. Round Two i. #5 Open House (switch from RFP) – OK having this before the NRD Board meeting. Scheduled April 14th at 6pm. ii. #4 NRD Committee – Scheduled April 14th at 1pm, regular meeting. JEO will then facilitate the Open House afterwards. iii. #6 NRD Board – final presentation and expected Board acceptance of the report. Scheduled for April 23rd.

4. Data Collection a. Groundwater and stream data collection – Most of this is complete. JEO will create a summary and provide the NRD to see if anything else can be added. b. Site visit and walk stream same day as Meetings #2 and #3 – The NRD has an easement for stream maintenance on the portion that needs to be walked.

5. Final Deliverable a. Early-May 2020 following Board Presentation, or late-April.

Other Notes: • Will ask the county if there is interest in road structures anywhere in the Mira Creek watershed. • Primary goal of the meetings is to keep everyone informed. A traditional outreach method (flyers, letters, website) is OK to advertise the Open House. • JEO will establish a stakeholder list and provide to the NRD to add and edit.

Remaining Questions: 1. Should JEO communicate directly with the Village? If so, how is the primary contact? Or at least CC their contact in key emails? 2. Will the NRD arrange the meeting space with the Village?

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Meeting Minutes

DATE AND TIME | February 4, 2020, 3:00PM PROJECT | North Loup/Mira Creek Flood Prevention Study MEETING | Village/NRD/County Meeting LOCATION | North Loup Community Building

Attendance: See sign-in sheet

The purpose of this meeting was to introduce the flood prevention study, discussion the process, obtain data on problem areas, and discuss preferred solutions. Jake Miriovsky provided an overview of the project, shared general information on the watershed, and facilitated a discussion on problems and solutions. Notes from that discussion are below:

1) The current floodplain map was last updated in 2008. Since that time LiDAR has become available, culverts have been installed, bridges replaced, and Co-Op build a railroad car spur – all would affect the floodplain. The current map likely doesn’t accurately reflect the 100-year (1% chance) flood area. 2) Flood peaks occur from the South Tributary and North Tributary of Mira Creek, therefore each should be addressed. JEO has modeled the peak flows and will fine tune the model. 3) Initial model estimates show that approximately 2,500 acre-feet (AF) of flood storage upstream of North Loup would reduce the volume of water to the point Mira Creek wouldn’t overtop during a 1% chance flood event. 4) The cost of a berm on the south side of Mira Creek in town is directly tied to the number of dams or other flood diversion structures built in the watershed. The more structures, the smaller the berm. JEO will assess this balance as part of the study. 5) The impact of tail water from the canals hasn’t been specifically addressed but will be considered as part of the study. JEO will obtain data from each irrigation district. 6) The hydrograph presented at the meeting showing the peak flows from each sub-watershed didn’t show the level of the 1% flood, but could, that information is available and will be included in the report. 7) Solution – The group discussed the possibility of overflow channels at the lower end to expedite flows past the Co-Op. The creek meanders greatly at the lower end, causing restriction of flow. 8) Should dams be constructed, the property owner would retain ownership, and the LLNRD would likely obtain an easement for the flood pool and own the dam. Typically the LLNRD would also be responsible for dam operation and maintenance. 9) A new bridge was built in 2019 on Highway 11 and a new country road bridge is going in just northeast of the Highway 11 bridge. JEO will obtain plan sets for each bridge and adjust the model accordingly to predict how flows will be altered. 10) JEO will also include the two new culverts installed under the railroad tracks just east of the Co-Op railroad spur. 11) The railroad and restrictions in Mira Creek are issues and are causing water to back up into town. 12) The group discussed how the 2010 dam breach was not typical and not reflective of normal flood heights through the community. JEO’s model can predict dam breach inundation flow paths and will be used to determine the hazard level for any future dam, per NeDNR dam safety regulations.

Page [1]

13) The group discussed rising groundwater levels and JEO described how dry dams are a preferred option as they have less recharge and less potential to add water to the aquifer. 14) The group discussed how JEO will determine preferred locations in the watershed for structures. The further up the watershed you go, the less protection provided, due to dams capturing smaller drainage areas. This will be part of the evaluation process in the study. 15) The question came up if JEO would consider designing for more than the initial 2,500AF target. That would be a consideration, the greater the storage capacity, the greater reduction in flood risk. The LLNRD noted that the benefit-cost could lower if you build more than what is needed. 16) A question came up if the dam that breached had an affect on groundwater. It isn’t known how much that dam, or any dam, in the watershed are recharging groundwater. JEO will look at hydrogeology and soil types once preferred sites are selected to determine recharge potential. 17) The dam that breached was constructed to hold 350AF. 18) A combination of levees, dams, channel cleanout, and overflow channels are all considerations. 19) A question came up about how to address interior drainage, should a berm be constructed. JEO would most likely design a pump system that would move interior flows over the berm. 20) JEO will be evaluating what percentage of the 1% flood is held within the banks of Mira Creek. The model will produce an inundation area showing what parts of town would be expected to flood during that type of event, and others (2% or 50-year and 0.5% or 200-year event). 21) A typical timeframe to plan, design, obtain funding, permits, and build major flood control structures is 5 years, assuming there are willing property owners. Smaller projects, such as cleaning out ditches and culverts, could begin immediately. 22) The group discuss the possibility of moving the Mira Creek channel. Permitting and cost would be substantial. Building overflow channels would be significant easier to permit and less costly. There appears to be willing property owners within the areas targeted for overflows. 23) The group discussed non-structural options, such as buy-outs. This will be a consideration in the study. The LLNRD is currently assisting Columbus with potential buy-outs. 24) There have been no houses condemned as a result of flooding. There are several houses that are vacant in the flood area that are candidates for removal. 25) The Co-Op is the only business that is hit hard during flooding. The main street experienced minimal flooding. 26) JEO will talk with Valley County to see if there are locations for potential road dams to replace aging culverts, pipes, or bridges. 27) To this point there has not been direct communication with the railroad. 28) The group discussed if funding agencies would support projects that are specific to the railroad. The consensus was that if a project on private property had public benefit, such as a dam, that it would likely be supported. That could include drainage improvements at the railroad. This will be confirmed by JEO. 29) Randy Wadas stopped by briefly to share that a farm he rents would be a great spot for an overflow and the property owner has expressed interest. 30) JEO will work with North Loup Irrigation District to acquire data on the location of buried laterals. There are buried laterals in the area where overflows would be beneficial. 31) LLNRD will provide information on canal hydrology from the ELM model/study. 32) There are two locations where canals outlet to Mira Creek carrying water from Calamus Reservoir. These will be incorporated into the hydraulic model.

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Meeting Minutes

DATE AND TIME | February 4, 2020, 6:00PM PROJECT | North Loup/Mira Creek Flood Prevention Study MEETING | Stakeholder Group LOCATION | North Loup Community Building

Attendance: See sign-in sheet

The purpose of this meeting was to introduce the flood prevention study, discussion the process, obtain data on problem areas, and discuss preferred solutions to a larger group of stakeholders. Jake Miriovsky provided an overview of the project, shared general information on the watershed, and facilitated a discussion on problems and solutions. Notes from that discussion are below:

1) The majority of the meeting’s discussion was an explanation of a variety of alternatives and how they would be assessed in JEO’s hydraulic model. 2) The group expressed concern with Mira Creek being full of debris, large trees, trash, etc. that is causing flow restrictions. 3) Regular cleanout hasn’t occurred east of the County road bridge. 4) Some of the property owners doubt adding to the top of the existing berm would help. 5) Channel overflows are a popular solution and there are willing property owners. There are springs in the area of some of the meanders. 6) The group discussed a combination of alternatives, including varying sizes of dams, overflow channels, off-channel storage, flow diversions through a canal outlet to the North Loup River, channel cleanout, channel widening, and interior drainage improvements. 7) A concern was expressed that conversion of land to row crop would increase runoff and removed small dams that could have had a flood reduction benefit. 8) The Village questioned if they can start cleaning out the creek. It was determined that with permission, they could, but should verify with legal counsel before proceeding.

Page [1] The Ord Quiz, Wednesday, April22, 2020 Page3 Recommendations for Reducing Flooding in theMira Creek Watershed and Villageof NorthLoup Available for Public Feedback

22, 23 2, North Loup Flood Rlslc ReducHon Study -'-----' +-----.----, --Streams 'li..J 26 -- Canals c:JMira Creek Watershed North Loup Alternatives Considered 344 Flood Control Berm 02 i a, -stream Channel Cleanout .ml -� Diversion Channels - Detention Basins 10 -·- Dam Locations

-- ID 11

1' 15 1 l ,. 0 2 4 Miles • � I·- � ---l--- � :zol.--28 The Lower Loup Natural Re­ Projects Technician, at cleanout of the Mira Creek chan­ sources District (LLNRD) is seek­ [email protected] 308-728-3221. nel fromHighway 11 and down­ ing public input and comments The purpose of the North Loup stream approximately one mile, from those who live in and Flood Risk Reduction Study is to along with interior drainage im­ around North Loup or the Mira gather existing data, develop and provements, such as ditch and Creek Watershed, as the initial evaluate floodreduction alterna­ culvertcleanout, and culvert re­ recommendations to reduce tives, and make a recommenda­ placement. floodinghave been released. tion to the LLNRD and the Village The next steps include incor­ Due to Covid-19 and state re­ of North Loup. poration of public feedback into quired social dist�cing require­ On Feb. 4, 2020, multiple com­ the draftstudy and then delivery ments, the LLNRD in cooperation munity and Valley Countyrepre­ of the final document to the with JEO Consulting Group Inc. sentatives provided feedback to LLNRD in May. Should the proj­ (JEO), has made available a pres­ LLNRD and JEO on the flooding ect move forward, the LLNRD entation with the North Loup issues. Since that time, JEO cre­ will then work with the North Flood Risk Reduction Study re­ ated a flood model to illustrate Loup Village Board to identify sults. The presentation available the extent of flooding during fundingfrom local, state,and fed­ on YouTube can be accessed varying storm events and used eral sourcesand create a sched­ through www.llnrd.org or the model to show future condi­ uleto proceed to into finaldesign LLNRD's Facebook page. tions should projects be con­ and construction, which would After reviewing the presenta­ structed. take several years. tion, the public is then asked to Based upon a draft report For more information, please provide feedback between now being provided and presented to contact the LLNRD office inOtd and May 8, 2020. All questions the LLNRD Board of Directors on at 308-728-3221. The North and feedback regardingthe pres­ April 23, 2020, the community Loup/Mira Creek Floodingvideo entation and study can be di­ would achieve significant flood is loaded on YouTube and is on rected to Brian Kolar, LLNRD. rjsk reduction from a combina­ the · LLNRD website at tion of one large dam on the https://www.llnrd.org/news/com­ North Tributary, a berm on the ments-sought-on-north-loup-flood­ south side of the channel, ing-recommendations.html. Date Name Contact Type Comments 4/25/2020 Jim Goodrich Email Positive towards recommendations Postive toward recommendations, feels channel cleanout and berm will 4/26/2020 Corbin Jensen In Person work good, questions the cost/benefit of large dam

Dan Timmons called, 4/27 14:00. Owns ground SE ¼ Section 33-18-13W along Highway 22. Concerned about Detention Cell option and the possibilities of it going forward (opposed). Supports Big Dam, thinks it will do the most good, thinks the entire channel needs cleaned out. Bypass channel 4/27/2020 Dan Timmons Call is a stupid idea. Uncertain about Berm (doesn’t fully understand it). After looking at the recommendations provided byJEO, my opinion is to use a combination of the Berm, interior drainage improvements and Channel clean- out. The addition of the large dam would have relatively little impact for a large additional cost. Also, if the lower cost remedies I suggested don't provide the desired protection, the larger dam could be added at a later 5/4/2020 Roger Lansman Email date. Lives on Mira Creek downstream of North Loup. Agrees with the channel cleanout but need to divert creek to North Loup on Markvicka property (picture). Water will move to fast and effect downstream owners. Has been flooded 3 times last 10 years. Fully supports any dam structure that allows 5/5/2020 Ray Patrick Call infiltration and augments groundwater Downstream landowner, near Mira/North Loup River confluence. Has been flooded twice (2010, 2019). Original flow path of Mira was adjusted near her house to go straight to the river. Concerns of more water being pushed onto property faster with channel cleanout. Support both Berm and Dam options. Some berms installed north of house in late 2019, reduces some moderate 5/6/2020 Susan Manchester Call flooding

Agrees that the Berm and Channel Cleanout are good ideas. Was concerned about the property cost associated with the Berm, feels that the cost are extremely high. He mentioned the village could condem properties for the project, which Kolar informed should be a last resort and the NRD may not be in favor of such actions. Suggested that portions of the channel me shifted north to make room for the berm/channel. Heath asked why the Berm ends at the railroad grade, he feels the water could pass upstream through the railroad grade after it passes the Berm end and it could still flood parts of the town. The water has seeped/flowed through the railraod grade during past flooding. Suggested that parts of the channel me shifted 5/6/2020 Heath Berkel Call north to accomodate 5/7/2020 Laurie Christens Call Positive towards recommendations Talked with Russ. Agrees with the Berm and Channel Cleanout, indicating that will help the town in the long run. Opposes the dam option, has groundwater concerns in the area as well as the potential added recreation use concerns associated with the new dam. Is an advocate for the 5/8/2020 Larry White Call Bredthauer dam.

Has a property (ag) that could be impacted by the berm, the extra water pushed onto his property would have a negative impact. Wants assurances on debris removal following a flood. Also has downstream concerns with the channel being cleaned out moving more water downstream faster. Favors a cutoff or overflow channel on the very north bend nearest to North Loup to take Mira Creek straight to the river. Concerned about outfall locations, 5/8/2020 Ron Wolf Call overflowing downstream of town. Proponent of any new dam structure. Not enough time to provide comment, there are localized water issues and too much water flooding fields. Has empathy for North Loup but is cautiosly opposed to a dam. Does not want to see taxes raised for a dam and believes that if it benefits flooding and recreation, those sources should pay for it. Realizes a dam may be the best option but doesnt want to see anymore 5/8/2020 Art Duvall Call farmground removed in Mira Creek. 5/8/2020 Don Dierberger Call Dam will not work, does not want his pasture tore up. Kolar called back 5/11/20. Does not support a large wet dam and would prefer a dry dam. He does not want land taken out of production or to loose the tax base from properties. Recommends the rehab of the smaller farm 5/8/2020 Larry Koelling Call dams that are in bad condition or that have been removed. Kolar called back 5/11/20. Opposed to the new dam location and design. Thought the landowners should have been contacted/informed of the concept dam project. Feels a dry dam may be a potential? Concerned that any dam/structure would have a negative effect on the already high groundwater levels in Mira Creek. Believes the town would benefit from the 5/8/2020 Andy Bredthaurer Call berm and channel cleanout. Kolar called back 5/11/20. Thinks channel cleanout would be a big help. In favor of other projects as well. Doesn't know if the big dam is exactly what needs done but thinks the water needs to be slowed/held upstream to 5/8/2020 Randy Cadek Call prevent flooding in town. Opposed to the dam option. Looking at the presentation the dam does not siginificantly change the flood boundary around North Loup. Thought the Heath Hadenfeldt (Not A Mira Creek landowners should have been contacted/informed of the concept dam 5/11/2020 or North Loup Resident) Call project. The cleanout and berm appear to be good options. !(

S Ord p No ri Mira Creek Watershed rth ng Lo C up r Overview River . NeDNR Streamgage Ord Ethanol Plant !( NeDNR Dams JEO Identified Dams Streams UV11 Canals Mira Creek Watershed . r C City Boundaries ane D County Boundaries Zone A Floodplain

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O a k Valley Greeley C r County County . Low Hazard Lagoon Dam Davis Creek Reservoir 0 2 4 Miles UV58 ± Davis Cr. 2020 Sponsored by: NORTH LOUP/MIRA CREEK FLOOD PREVENTION STUDY

The Lower Loup Natural Resources District (LLNRD) continues to VILLAGE OF support its communities with identifying issues and providing solutions to reduce the risk from flooding. The LLNRD has hired NORTH LOUP JEO Consulting Group, Inc. to study the Mira Creek watershed, interior drainage deficiencies, and obtain public feedback on ──── potential solutions. Consulting Study Components Engineer: • Surface Drainage Data Collection • Community Engagement • Floodplain and Stormwater Evaluation • Hydraulic Modeling • Project Recommendations and Reporting • Funding Strategy

Study Purpose ──── The goal is to reduce the threat of flooding for North Loup. The objective is to create an understanding the hydrology of the Mira Creek watershed and the inadequacies of the interior stormwater infrastructure; both are key to identifying long-term flood reduction solutions.

Schedule INFORMATION • Kickoff – January 2020 Lower Loup NRD Contact: • Data Collection and Stakeholder Input – February 2020 Tylr Naprstek • Analysis and Conceptual Design – March 2020 Assistant Manager • Reporting and Final Presentations – April 2020 308-728-3221 [email protected]

Public Open House Village of North Loup A meeting is scheduled for April 14th at 6pm, at the Community Carrie Hansen Building, 112 B Street, to provide information on the issues and to Village Manager obtain input on solutions. 308-496-4362

[email protected]

UV11 20 21 22 23 24 19 20 21 22 23 24 19 20 21 22 23 24 19 North Loup Flood Risk Reduction Study UV11 Streams 29 28 30 29 28 29 27 25 30 27 26 25 27 26 25 30 28 26 Canals Mira Creek Watershed 31 33 33 34 35 36 32 34 35 36 31 32 33 34 35 36 31 32 North Loup UV11 Alternatives Considered Flood Control Berm 04 02 05 04 03 02 01 06 05 02 05 04 03 01 06 03 01 06 Stream Channel Cleanout Diversion Channels 09 09 07 08 09 10 11 12 07 08 10 Detention11 Basins12 10 11 12 07 08 Dam Locations Dam Pools 15 14 13 18 17 17 16 15 14 13 18 17 16 15 14 13 18 UV70 16

22 23 24 19 20 24 21 22 23 24 19 20 21 21 22 23 19 20 `

29 28 26 25 30 29 28 28 27 26 25 30 27 27 26 25 30 29 ` ` 36 32 33 34 35 36 31 32 33 35 36 31 32 33 34 35 31 34 UV22

05 05 04 03 01 06 05 04 03 02 01 06 04 03 02 01 06 02 Preferred Alternatives - Large Dam UV11 UV22

- Flood Control Berm 08 07 08 09 11 12 07 09 07 12 10 10 11 12 08 09 10 11 - Channel Cleanout

13 18 15 14 13 18 17 18 14 17 16 15 14 13 17 16 15 16

24 19 0 24 2 4 23 19 20 21 22 23 24 20 21 22 23 19 20 Miles 21 22 ± 26 28 29 28 27 26 25 30 29 28 27 25 30 29