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Barr Lake Spillway

Barr Lake Spillway

The State of Colorado determined that the spillway at Barr Lake was inadequate to safely pass the inflow design storm. ERC was retained to evaluate existing and future conditions and design a spillway upgrade. ERC evaluated extreme precipitation conditions and defined the Probable Maximum Precipitation of 30 inches in a 48-hour period. When routed the storm produced a peak inflow rate of approximately 40,000 cfs with a total runoff volume of 13,000 acre-feet. Hydraulic modeling showed that a 185 spillway was required to safely pass the inflows while maintaining the required freeboard without raising the dam. The design included replacing the existing earthen spillway with a composite concrete, riprap and soil cement spillway. Additionally, over three miles of perimeter dikes were designed and constructed to control water levels during the design event. ERC completed design, permitting and construction management for the project.

Project Categories:
irrigation

Bear Creek at O’Fallon Park

Bear Creek

Kittridge, CO

O’Fallon Park in Kittridge CO is a heavily used park for summer recreational activities. The local Trout Unlimited Chapter was interested in restoring aquatic habitat for a 1,600 foot section of Bear Creek as it runs through the Park. ERC completed design, permitting and construction activities for the project including creation of nine, self-scouring deep overwintering pools that were generally absent through the area. Design used faster moving water from riffles to provide the higher energy to flush sediment from the pools throughout the year. Key placement of instream boulder habitat enhanced usable cover for trout. The project included moving the stream away from State Highway 74 and creating a riparian fringe barrier between the highway and the stream to minimize sand and other sediment loading that had previously been occurring from the road. ERC led volunteer efforts that included planting riparian vegetation for bank stabilization and terrestrial habitat creation.

Project Categories:
stream-restoration

Beaver Valley Ranch

Beaver Valley Ranch

North Fork of the Williams Fork, Hayden, CO

Beaver Valley Ranch is a private fishing ranch located in rural Routt County. Objectives of the project were to enhance fishing habitat and angling opportunities along a 1,500 linear foot stretch of the North Fork of the Williams Fork River. ERC’s design created sequences of riffle and bend pools based on the natural alignment of the stream system. Improvements utilized on-site material for channel shaping, instream habitat features and bank stabilization, minimizing the need for import and reducing overall project costs. Work was completed within a two week window to minimize impacts on ranching and impacts to anglers using the site.

Project Categories:
stream-restoration

Big Thompson River

Big Thompson River

City of Loveland, CO

Infrastructure associated with the City of Loveland’s water treatment plant was compromised as a result of the 2013 floods. After emergency repairs were completed, the City desired restoration work that would not only protect infrastructure but also improve the ecological function of the damaged river. ERC’s design/build work focused on reestablishing natural channel form and function to this degraded reach. In areas where excessive stream widening occurred during the 2013 flood, ERC returned the stream to its appropriate width. Riprap that had been installed immediately following the flood was filled and vegetated to promote ecological value and natural stream planform and profiles were reestablished through channel reshaping and construction of riffle/pool sequences that had been lost.

Project Categories:
stream-restoration

Blue River Phases I and II

Blue River Phases I and II, Silverthorne, CO

Silverthorne, CO

ERC was hired by the Town of Silverthorne to improve angling on an approximately 3,000 foot stretch of the Blue River below the Dillon Dam. This section, which is gold medal water, was suffering from poor habitat and limited angling opportunities. ERC was hired to design, permit and construct improvements aimed at enhancing both the aquatic habitat and the angler experience. Improvements included full reshaping the overly wide channel so that the new stream channel geometry matched flow releases from the dam. The success of the project led the Town to hire ERC to complete restoration on two additional sections of the Blue River totaling and additional 3,500 feet as part of a Phase II project.

Project Categories:
stream-restoration

Blue River, Getz Ranch

Getz Ranch

The Getz family property in Summit County includes approximately 1,300 feet of the Blue River, inclusive of a 500 foot high water side channel. They desired to enhance the aquatic habitat to create a better fishery during high and low flow conditions. ERC developed a design plan that controlled flows between the main and side channels and optimized aquatic habitat in each. Plans included buried cross channel cobble bars to split flows between the channels, riffles constructed of salvaged instream cobble and deeper pools designed to hold more larger fish throughout the year.

Project Categories:
stream-restoration

Blue River, Maryland Creek Ranch

Blue River, Maryland Creek Ranch

Silverthorne, CO

The Maryland Creek Ranch development in Summit County includes approximately 3,500 feet of private water on the Blue River, including side channels. ERC designed and constructed improvements along this full stretch to optimize aquatic habitat and maximize holding capacity for large trout. The design included a deep thalweg throughout the full project reach to ensure quality habitat was retained even at times when flows are limited to minimum releases from Dillon Dam. ERC’s natural restoration created 11 different stream segments, each with its own unique habitat features to provide anglers with a variety of fishing experiences. The project, which included full reshaping and grading of the entire 3,500 foot section was completed within a three week window given tight schedule limitations imposed by project permits.

Project Categories:
stream-restoration

Boulder Creek Master Plan

Boulder Creek Master Plan

Boulder Creek, like many of Colorado’s front range streams, was significantly altered by the 2013 floods. ERC was part of a team of consultants tasked with evaluating the environmental and geomorphologic conditions of the stream and developing a master plan for future resilient improvements. ERC evaluated historic aerial photographs of Boulder Creek to understand evolution of the stream’s alignment during recent and pre-development periods. From this assessment, a range of natural sinuosity and meander wavelengths were defined and alignments for future restoration were identified. Typical cross-sectional geometries that replicate natural stream conditions were determined for low flow, bankfull flow and flood flow events. Critical habitat features along the riverine corridor were defined and recommended riparian buffer zones to protect the corridor from further development were determined.

Project Categories:
stream-assessments

Boxwood Gulch Fly Fishing Ranch Phases I – III

Boxwood Gulch Fly Fishing Ranch

North Fork of the South Platte River, Shawnee, CO

Boxwood Gulch is one of the premier private fishing waters in the Denver metro area. With its reputation for holding large numbers of large trout, quality habitat needed to support these fish was a vital concern. ERC was hired by Boxwood Gulch to improve the habitat and holding water for an initial 2,200 foot section of the North Fork of the South Platte River. Variable flows are one of the main challenges facing this fishery. Located below Roberts Tunnel, this reach of water is subject to extreme low flows in winter months when no tunnel releases are made as well as extended periods of high flows throughout the summer and fall months. ERC’s design addressed these flow challenges and the need for significant habitat. Improvements included a wide array of techniques aimed to optimize habitat throughout the varying characteristics of the site. Larger cascade features were utilized in the narrow, steeper canyon sections. Longer riffle and bend pools were created where they fit well into the stream alignment and a deep, meandering thalweg with extensive instream cover was provided throughout. The success of ERC’s initial improvements has led to two additional phases of work being undertaken. Completed improvements provide a great variety of angling opportunities for all types of fly fishing over the full spectrum of flow conditions.

Project Categories:
stream-restoration

Brush Creek

Brush Creek

Snowmass Village, CO

The Town of Snowmass Village is one of Colorado’s premiere ski and outdoor destinations. In the early 2000s when the Town undertook a major development project to modernize infrastructure and amenities, ERC was hired to restore Brush Creek, one of the first things visitors to the Town notice upon arrival. Past development had encroached upon the river, and it didn’t provide significant ecological benefits or recreational opportunities. ERC’s design recreated a stream segment that optimized habitat while providing a more enjoyable and user friendly resource. The stream was re-meandered and a total of 27 step/pool and riffle/pool features were created to provide pool habitat over a 1,300 foot segment. The corridor along the stream was regraded and native riparian was planted to create a healthy riverine system to support aquatic and terrestrial habitat. These improvements served to beautify the Town entrance.

Project Categories:
stream-restoration

Buffalo Peaks Ranch, Middle Fork of the South Platte River

Buffalo Peaks Ranch

Park County, CO

Colorado Parks and Wildlife holds an easement that allows fishing significant portions of the Middle Fork of the South Platte River in Park County.  One of the factors that limit the aquatic habitat through much of this water is pool habitat. ERC was selected to develop plans to optimize habitat along a 21,700 foot stretch of the Middle Fork known as Buffalo Peaks Ranch. The design included 79 habitat segments, each with a created pool to address the habitat limitations of the area. Pools were designed to work in combination with cascade features, riffles and bends, depending on site specific conditions. Funding was raised allowing for a priority reach of 9,800 feet to be completed. Using a natural restoration approach, ERC created 33 unique habitat units, each with a deepened pool along the priority reach.

Project Categories:
stream-restoration

Burlington Canal Headworks

Burlington Canal Headworks

ERC designed and oversaw construction to modernize the main Burlington Canal headworks off of the South Platte River. The diversion structure included four main crest gates (two 6 foot gates and two 12 foot gates) a 4’ x 13’ crest gate for bypass flow operations and a 4’x4’ sandout gate all with flow measuring capabilities. ERC’s work included hydraulic modeling, gate design, 404 and floodplain permitting and construction observation. The completed facility has the ability to pass and measure flows up to approximately 1,000 cfs. Gates were designed to fit within the original Burlington diversion structure while improving operational flexibility and safety.

Project Categories:
irrigation

Church Ditch Headgate 53 Retaining Wall

The Church Ditch hired ERC to repair a concrete-block retaining wall holding back high banks along the ditch in Arvada. The wall showed signs of heaving and overturning in several spots due to a poor design and the expansive soils in the area. ERC designed a concrete footer for the existing blocks and a system of steel angles to tie the blocks together. Approximately 800 linear feet of wall was repaired. The sections were between 6 and 10 feet tall. Design work included hydraulics, stability analysis, and permitting. ERC also managed the project by providing construction oversight.

Project Categories:
irrigation

Church Ditch Headworks

CDWA headworks

In 2016-2017, ERC managed the project to modernize the headworks structure of the Church Ditch on Clear Creek in Golden, Colorado.  During the design phase, ERC conducted hydraulic modeling to size new gates.  These included two 4-ft by 4-ft Fresno slide gates, a 4-ft Rubicon overshot gate for controlling upstream head, and a 4-ft slide gate for flushing debris.  We also worked with the City of Golden and Jefferson County Open Space to permit the project.   In the construction phase, ERC provided bid support to select a contractor then provided oversight and observation to ensure a smooth process.  The structure includes security fencing, solar power and the ability to operate the gate and measure flows remotely.

Project Categories:
irrigation

Church Ditch Leyden Flush Structure

The Leyden Flush Structure is a turn-out point for Church Ditch to bypass excess flows and flush sediment and other debris from the upper system. In 2017, the Church Ditch hired ERC to design a new structure to replace the leaky gates, old concrete rickety bridges and a manual stop-log system. ERC designed a new structure to include two concrete headwalls, a 12-ft by 4-ft canal slide gate, a 4-ft by 4-ft Rubicon SlipGate for flushing, two steel access bridges, and security fencing. The gates are solar powered and remotely operable. Design work included hydraulic modeling and gate sizing.   ERC also managed the project by providing construction oversight.

Project Categories:
irrigation

City of Westminster On-Going Water Rights Support

City of Westminster On-Going Water Rights Support

ERC provides on-going water rights and water resources planning services for the City of Westminster focused on planning, developing and protecting the City’s water supply. These services include:

  • water rights evaluation and analysis,
  • participation in court proceedings and negotiations to acquire, transfer and protect water rights,
  • preparation of 26(a)(2) disclosures for water rights cases,
  • providing expert testimony in water rights litigation and determination of protective terms and conditions,
  • involvement in water rights agreements and settlements,
  • providing engineering calculations and reports related to water matters,
  • enhancement and development of water accounting procedures and forms,
  • performance of water resources modeling, planning and operational studies,
  • drought analyses, quantification of consumptive use related to water rights acquisition and change of use proceedings, and
  • investigating exchange potential and water availability (legal and physical).
Project Categories:
water-resource-planning

Clear Creek

Clear Creek

Golden, CO

Clear Creek serves as an integral component of the City of Golden.  The City in recent years has undertaken significant efforts in developing the Creek corridor as a recreational and natural focal point with the city.  Through  improvements and  planning  the  corridor  has developed  into an  extremely successful  public  amenity  as  observed  by high year round  recreational and visitor use. This high recreational use and great demand periodically exceeds the corridor’s capacity.  A growing concern has developed that when high recreational use exceeds capacity, not only does user conflict increase and experience quality decrease, but the riparian and aquatic ecosystem health may also be significantly at risk.  ERC was contracted by the City to conduct an assessment of the corridor in the context of riparian and aquatic ecosystem health as well as provide potential ecosystem protection and management strategies.  The Project Area included approximately 1-mile of Clear Creek extending through the heart of the City.

ERC performed an existing conditions assessment of the Creek corridor to identify the gradient of ecological condition by identifying areas of high, moderate and low ecological integrity.  Based on the existing condition assessment and a thorough understanding of recreational use patterns, ERC developed ecosystem protection and management strategies which focused on proving enjoyable and safe recreation use while preserving and enhancing the ecological integrity of the Creek natural resources.  Sixty specific areas of interest were identified.  Management strategies were developed for each area of interest, ranging from preservation of existing high quality habitats through use elimination, bio-engineered bank stabilization, structural stabilization (boulder terrace), formalized access points and riparian habitat restoration.  ERC assisted the City with public open house presentations of the project as well as detailed design development, project prioritization, USACE permitting, City floodplain permitting and construction implementation of select improvements.

Project Categories:
stream-restoration

Community Ditch Improvements

The Community Ditch through Eldorado Canyon was historically one of FRICO’s most difficult sections to maintain of its 400 mile canal system. Bank sloughing, icing, seepage, liner damage and limited access all contributed to operational challenges in this section. FRICO hired ERC to develop a solution that would allow water to be conveyed through this ½ mile section in a more efficient manner. ERC’s solution replaced the open trapezoidal channel with a box culvert. The culvert was designed to fit within the narrow, meandering confines of the old ditch alignment, which allowed for only inches of tolerance in the box design. Maintenance access, which had not existed through this section, was provided on the top of the culvert. Design work included hydraulic modeling, modifications to intake gates and measuring devices, evaluation of rockfall hazards and Boulder County permitting.

Project Categories:
irrigation

Dam Breach Modeling

Hydrology

ERC has completed several dam breach analyses for municipal reservoirs and mining facilities in states such as Colorado, Arizona, Montana, and South Carolina, among others. The analyses have included sizing flow hydrographs resulting from a dam breach, mapping flood inundation extents (using both one-dimensional and two-dimensional modeling methodology), and determining the downstream hazard classification of each dam in respect to local regulations. ERC has also aided in the creation of Emergency Action Plans (EAPs) for the dams where the downstream hazard potential of the dam is found to be great enough to require one.

Project Categories:
irrigation

Denver Water Moffat Project

Moffat EIS

ERC was the stream morphology and sediment transport resource specialist tasked with evaluating impacts of Denver Water’s Moffat project on front-range and west slope stream systems. Channel evaluations encompassed over 200 miles of streams including the Fraser, Williams Fork, Colorado and Blue River on the west slope and South Boulder Creek and the North Fork of the South Platte River in the front range. Field work included site assessments, surveying and sediment sampling. Existing stream conditions and recent trends in channel evolution were evaluated from this field program, evaluation of historic conditions (aerial and ground photos, assessment of USGS stream gage shifts and repeated historic cross-sectional surveys for signs of aggradation or degradation) and numeric modeling. Modeling defined sediment supply, sediment transport capacity, effective discharge, the frequency of Phase 2 sediment transport and the magnitude of specified recurrence interval flood flows. Quantitative and qualitative stream impacts anticipated as the result of the planned Moffat project were determined by defining flow changes associated with the project and overlaying these hydrologic alterations on knowledge of the behavior and resiliency of the existing stream systems. ERC’s work included design of front-range and western slope stream mitigation aimed at providing functional stream uplift to offset project impacts following the stream functional pyramid approach.

Project Categories:
stream-assessments

Denver Water Platte & Colorado Simulation Model (PACSM)

Moffat Collection System EIS

ERC was the surface water resource specialist tasked with reviewing Denver Water’s Platte and Colorado Simulation Model (PACSM) of the Colorado and South Platte River Basins for Denver Water’s Moffat Collection System Project EIS. ERC identified and implemented changes to improve PACSM. ERC’s review of modification of PACSM required detailed knowledge and understanding of South Platte and Colorado River basin administration, water rights, facilities and operations. ERC reviewed the configuration of each of the EIS alternatives in PACSM and was responsible for assessing Denver Water’s diversions under the EIS alternatives and the effects on other water rights and streamflows in the Colorado River and South Platte River basins. ERC used model output to complete the surface water impacts analysis and associated sections of the EIS document and support evaluations of resources affected by changes in flow and reservoir contents including wildlife, aquatic resources, recreation, stream channel morphology, wetlands and riparian habitat, floodplains, and water quality. ERC also assisted with the review of the Purpose and Need Statement and alternatives development and screening for the EIS process.

Project Categories:
water-resource-planning

Dr. Rich Weiss Park, Yampa River

Dr Rich Weiss Park

City of Steamboat Springs, CO

Dr. Rich Weiss Park is one of the most heavily used pocket parks within the heart of Steamboat Springs. This heavy use has led to loss of significant riparian vegetation, bank erosion and degradation of the hot springs that are a central feature of this park. ERC was hired by the City to design improvements that would stabilize the stream bank and improve water quality through minimization of erosion and reestablishment of a riparian interface. ERC’s work also included redesigning the hot springs area to make it more accessible and safe for users. Work required coordination with the Army Corps of Engineers, Colorado Parks and Wildlife and floodplain analysis to ensure proposed modifications did not increase safety hazards along this 250 foot stretch of river.

Project Categories:
stream-restoration

Eagle River Phases I and II

Eagle River Phases I and II, Minturn, CO

Minturn, CO

The Town of Minturn desired to restore the Eagle River through Town to mitigate past impacts to the aquatic and riparian corridor that had been caused by channel encroachment and upstream mining activities. ERC first developed a master plan for stream restoration for a 4,100 foot stretch of river through the heart of Town. Improvements include full reshaping of the stream, creation of natural riffle/pool/glide features over a mile of bank stabilization, water quality infrastructure and over two acres of wetland and riparian creation. ERC assisted the Town in securing over $1M in funding for the project and completed all improvements for this design/build project. Given the success of this Phase I project, the Town received an additional $1M in grant funding for a second phase of the work. Phase II work resulted in the creation of an additional 17 natural riffle/pool/glide complexes and additional 1.6 acres of wetland and riparian creation and multiple angling and boating access points along a one mile stretch of the Eagle River.

Project Categories:
stream-restoration

East Fork of Parachute Creek, Roan Plateau Fish Barrier

Roan Plateau Fish Barrier

Garfield County, CO

Colorado Trout Unlimited and the Bureau of Land Management desired to reestablish a sustainable population of native Colorado River Cutthroat Trout (Oncorhynchus clarkia pleuriticus) within the Roan Plateau. The project site is located more than an hour from a paved road requiring special attention to constructability and long-term maintenance. ERC was selected to complete the design, permitting and construction of a barrier that would be used to separate the upstream habitat from non-native downstream fish. Our work scope included defining a location that was suitable for a barrier and evaluating a range of potential barrier types. A vertical barrier was selected over velocity barriers and fish screens given its ability to operate over a wide range of flows and its favorable maintenance requirements. Detailed hydrologic, hydraulic and geomorphologic analysis were conducted to ensure the barrier would prevent upstream migration, be in balance with the surrounding stream conditions and be capable of conveying flows ranging from typical baseflows to peak runoff from the 100-year flood event.

The result was a six foot high structure that utilized cast in place concrete and native channel substrate. A low flow channel created a stream width that mimicked the upstream and downstream channel planform and an overflow allowed for passage of the 100-year event. Scour pools were prevented using a concrete apron and banks were stabilized with rock and native vegetation. ERC constructed the barrier at this remote site using primarily hand labor and an on-site concrete batching operation.

Project Categories:
stream-restoration

East River, Eagle’s Nest Ranch

Eagles Nest Featured Project Featured Image

In 2006 Dr. Henry Estess initiated development of an ambitious habitat improvement project in the lower meadow of Eagle’s Nest Ranch. Ecological Resource Consultants, Inc. (ERC) worked closely with Dr. Estess to develop a plan which would maximize and diversify… Read more »

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Project Categories:
featured
stream-restoration

East River, Reserve on the East River

Reserve on the East River

Gunnison County, CO

The Reserve on the East River is an exclusive development near Crested Butte developed around natural amenities including fly fishing. Given the high flows that exist in the East River during the spring, the main river can often be difficult to fish. The Reserve retained ERC to develop a side channel fishery that would be fishable during these high flow periods and also provide a different angling opportunity throughout the fishing season. ERC’s design included evaluating flows in the river and incorporated buried grade control features to regulate the amount of water entering the side channel. A total of 21 individual rock and pool features were then created within the 1,700 foot side channel, providing a great variety of habitat and angling opportunities. Instream features included faster moving, aerated riffles, a meandering low flow thalweg, bobble bars, cascading water features, current deflectors and scour pools.

Project Categories:
stream-restoration

El Sauzal Closure

El Sauzal Closure

Water management was a significant challenge at the El Sauzal mine given the site’s steep topography and flashy rainfall history. ERC was retained to develop a diversion and water management plan for the mine’s closure. Site and historic regional precipitation records were evaluated to define the magnitude of rainfall expected at various frequencies. A risk assessment was completed to consider flow frequency and facility sizing. Based on this analysis the mine selected the 100-year storm event for design. ERC’s design included over six kilometers of channel. Design also included sediment ponds, energy dissipation structures, stilling basins and rundowns. Due to the varied flows, slopes and ground conditions a number of types of channel armoring were required with armoring including vegetation, bedrock, concrete and geowebs.

Project Categories:
mining

Farmer’s Reservoir and Irrigation Company (FRICO) On-Going Water Rights Support

Farmer’s Reservoir and Irrigation Company (FRICO) On-Going Water Rights Support

ERC provides on-going water rights and water resources planning services for FRICO that includes planning, developing and protecting FRICO’s water supply. These services are focused primarily on water rights protection and participation in water rights cases on FRICO’s behalf. Services include:

  • participation in court proceedings and negotiations,
  • preparation of 26(a)(2) disclosures for water rights cases,
  • providing expert testimony in water rights litigation and determination of protective terms and conditions,
  • quantification of historical consumptive use related to change of use proceedings,
  • investigating exchange potential and water availability (legal and physical),
  • involvement in water rights agreements and settlements,
  • providing engineering calculations and reports related to water matters,
  • development of water accounting forms and on-going accounting support, and
  • performance of water resources modeling, planning and operational studies.
Project Categories:
water-resource-planning

Fort Collins Natural Areas

Fort Collins Natural Areas

ERC provided consulting services, design, permitting and construction services to the City of Ft. Collin’s natural areas program. As part of ERC’s services we reclaimed upland habitat, riparian zones, created wetlands and stabilized river and lake shore property. Full design/build restoration services were provided at Arapaho Bend, McMurray, Salyer, Bobcat Ridge and Rivers Edge Natural Areas. Work focused on restoring impacted areas to their natural setting. As part of our services we developed wildlife habitat, created shallow water ponds for waterfowl production, reclaimed a gravel pit, created wetlands, reestablished a riparian forest and addressed deficiencies in soil chemistry to promote natural revegetation evolution.

Project Categories:
environmental

Fountain Creek

Fountain Creek

Colorado Springs, CO

ERC was retained as part of a design team to assist with improvements on an urban section of Fountain Creek through Colorado Springs. Work on this 3,800 foot section included bioengineered bank stabilization and intensive native riparian planting to aid in flood flow retention and terrestrial habitat. Work included realigning the channel, increasing channel conveyance and relocating residences and businesses for public protection during peak flood events in Fountain Creek.

Project Categories:
stream-restoration

Fraser River

Fraser River

Granby, CO

The Fraser River is influenced by the significant amount of diversions for both water use in the Front Range and irrigation use in the western slope. As a result, current flows in the Fraser River have been reduced to approximately half of their historic levels. The Town of Granby wanted to enhance the health of the Fraser River through Town and make the stream a better community amenity. ERC was retained by the Town to develop and construct these river improvements. ERC’s restoration work reshaped the Fraser River along a continuous 1,700 foot section of stream. The channel was narrowed from a maximum width of 115 feet to a typical bankfull width of 45’ – 55’. The modified, narrower channel section was constructed to meander within the confines of the historic channel and specific aquatic habitat improvements including pools, riffles and instream habitat clusters were incorporated into the design and an existing fish migration barrier was modified to promote passage.

Project Categories:
stream-restoration

Haile Gold Mine Stream Assessment and Monitoring

Haile Gold Mine Stream Assessment and Monitoring

The Haile Gold Mine is going to alter flows in area streams within and adjacent to the mine development. ERC was retained to evaluate and document flows and stream conditions within the mine, adjacent to development and in areas outside of the zone of influence of the mine to facilitate the long-term assessment of potential mine impacts. Baseline studies included stream surveys, sediment sampling, bank stability evaluations and flow quantification. As part of this initial assessment ERC established permanent monitoring sites and designed a system of flumes, weirs and USGS type stream gages for flow measurements. Nested piezometers were designed and installed to inform the understanding of variability in surface flows and groundwater levels and their joint contributions to the riparian wetland system that exists on site.

Project Categories:
stream-assessments

Haile Gold Mine – South Carolina

Haile Gold Mine – South Carolina

Gold was first discovered in Lancaster County, South Carolina in the 1820s. In 2007 Romarco Minerals acquired the property and began the process of planning, designing and permitting a modern mine at this historic location. ERC provided water resource and environmental consulting services through feasibility, permitting and final design. Environmental work included baseline wetland delineations, habitat functional assessments and impact assessments. Water resource work included climate evaluations, hydrologic and hydraulic assessments, water balance modeling, water supply assessments, spillway design and erosion control. ERC was particularly instrumental throughout the permitting process given our technical and regulatory expertise. We worked with the Corps and their third-party contractor during the EIS process and helped secure permitting which has led to operations of what will become the largest gold mine in the eastern US.

Project Categories:
mining

Lincoln Hills Fly Fishing Club

Lincoln Hills Fly Fishing Club, South Boulder Creek, Gilpin County, CO

South Boulder Creek, Gilpin County, CO

ERC completed design and permitting and performed design/build construction on an approximately 5,000 foot stretch of South Boulder Creek for this private fishing club. The project objective was to maximize holding capacity for larger fish.  Improvements were designed to fit into the varying natural terrain of the property and included items such as boulder plunge features in the higher gradient canyon sections of the property, riffle pool features in the lower gradient section of the stream and micro habitat improvements throughout the length of the project. All fishing improvements were made with the angler in mind and provided a range of habitat types and fishing opportunities.

Project Categories:
stream-restoration

Long Meadow Ranch, North Fork of the South Platte River

Long Meadow Ranch

Shawnee, CO

Flows in the North Fork of the South Platte River are highly altered due to releases to the front range from Dillon Reservoir and vary from low baseflow conditions in the winter to sustained high flows from June through September. ERC was hired to design and construct improvements that would improve holding capacity for large trout throughout the year. Improvements included riffles, bend pools, step pools, rock and woody debris for micro-habitat and bank stabilization. After improvements this section has become a flyfishing destination providing a first class fishery in close proximity to the Denver metro area.

Project Categories:
stream-restoration

Minera Panama – Panama

Minera Panama

With its location in the rainforest and in an environment that receives nearly 5 meters of annual rainfall, water management is one of the critical technical challenges for Minera Panama. ERC was brought into the project due to its experience characterizing and developing water management plans for mines in locations with extreme climatic conditions. Our first task was to establish estimates of design rainfall events and associated runoff for short-term and extended wet cycle conditions. Our next challenge was water diversion. The main local river, the Rio Botija, ran right through the initial mining target and needed to be diverted around the planned pit. ERC’s design included a risk based assessment of tradeoffs between design storms and allowable pit flooding. The ultimate design required lining to minimize seepage and related instability adjacent to the pit wall for the 2 kilometer channel. Finally ERC developed an operational water balance model for mine personnel use in managing pit sumps and surface water dewatering systems.

Project Categories:
mining

Newmont Nevada Operations

Newmont Nevada Operations

ERC has provided water resource and environmental services to Newmont Mining Corporation at their eight Nevada sites. At all locations, accurate quantification of water requirements and needed storage capacity is paramount to efficient and safe operations. Climatological conditions have been quantified to allow the mines to understand both short-term and multi-month and year weather conditions that can impact water management. Probabilistic water balance modeling has been completed to predict operational variability at tailings storage facilities, heap leaches and operations that have multiple interlinked facilities. ERC’s stochastic models have been used for project planning, permitting, design and closure scenarios. We have been involved in overall water management of facilities including estimates of fresh water requirements and design of diversion channels and sediment control measures. ERC has also provided ecological planning and design services for heap cover/closure design, revegetation planning and landscape-based closure reclamation.

Project Categories:
mining

Platte River Ranch, North Fork of the South Platte River

Platte River Ranch

Owners of the Platte River Ranch were looking to transform their property into a top-notch fishery that both challenged their abilities and provided opportunities for children and beginner anglers to hone their flyfishing skills. ERC designed and constructed improvements that focused on providing a wide range of aquatic habitat and angling prospects that met this challenge. Restoration work included reconnecting two side channel segments, creating oxygenated riffles for macro invertebrate production, developing flat water for dry fly opportunities, construction of step pools and bend pools for refuge and glides and runs for traditional trout feeding lanes. To improve fishability for the variety of angler use ERC completed bank stabilization work, created access channels, provided rustic steps for easier access to challenging areas and created eddies for safety for children.

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Project Categories:
featured
stream-restoration

Rogers Park, Middle Boulder Creek

Rogers Park

Boulder County, CO

Rogers Park between Nederland and Boulder, CO provides a unique opportunity for public fishing access on a high mountain stream near significant population centers. ERC was hired by Trout Unlimited to optimize aquatic habitat and angling opportunities on this 2,200 foot stretch of Middle Boulder Creek. The improvements included nine different riffle/pool and step pool features each designed to fit into the varying stream gradient and offer a variety of habitat types. The stream was reshaped along its entire length to create a meandering thalweg that offers improved habitat during low flow periods. Significant bank stabilization work was included in the project to mitigate impacts of past foot traffic and the proximity of the road to the stream. Improved angler access was constructed as part of the river work and riparian vegetation was planted along the corridor to improve bank stability and provide overhead cover for the aquatic environment.

Project Categories:
stream-restoration

San Miguel River, Telluride Valley Floor

San Miguel River

The Town of Telluride Open Space San Miguel River Valley Floor Property had been heavily impacted by past land use practices. Historic mining contaminated the river and the construction of a rail line through the valley caused the once meandering… Read more »

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Project Categories:
featured
stream-restoration

South Platte River at South Platte Park Phases I – III

• South Platte River at South Platte Park Phases I - III, Littleton, CO

Littleton, CO

The construction of Chatfield Dam in the Denver Metropolitan area had a significant impact on the health of the South Platte River. Flow regulation altered the natural hydrograph of the stream and the dam’s trapping of sediment created a stream system that was sediment starved.  As a result significant channel downcutting occurred and the stream geometry, which was established based on higher natural flows, was overly wide for the regulated flow regime. ERC was contracted by Urban Drainage and Flood Control District to develop a master plan to enhance the natural characteristics of the stream and riparian corridor for this 2.4 mile reach of the South Platte. Stream improvements were intended to resize the active channel to be in balance with current reservoir releases and create improved aquatic and riparian habitat all while ensuring that the stream retains the hydraulic conveyance needed to minimize flooding. ERC’s initial geomorphologic assessments evaluated past and current flow hydrographs and development of hydraulic and sediment transport models to help define a stable channel configuration. Based on results of these analyses, ERC developed an overall enhancement plan which included creation of a meandering channel sized to convey current flows within the confines of the overly wide existing channel.  Low gradient riffles were designed to increase habitat variety and deeper pools were included to provide habitat critical for low flow conditions. This master plan also incorporated bank stabilization, protection of the local trail system, riparian corridor restoration, upland improvements and wetland creation. Bank stabilization was completed using a variety of structural approaches where needed to interrupt areas with active lateral migration and softer vegetated measures where possible. Improvements were prioritized based on relative benefits of individual stream reaches and shareholder/community input. Construction costs were developed as part of the master plan.

ERC’s restoration master plan was then used as an instrument to gather community support and project funding. The plan was endorsed by local jurisdictions, which contributed funds for the project and aided in additional fundraising for the proposed work. Phase I was completed in 2013 with Phases II and III completed in 2015.

Project Categories:
stream-restoration

Standley Lake Monitoring and Dam Break

Standley Lake Monitoring and Dam Break

ERC is responsible for the on-going monitoring and reporting of Standley Lake Dam in Westminster, CO. This large, high-hazard dam provides water to nearly 300,000 residential and is located in a highly urbanized area. ERC completes monthly inspections, monitors reservoir and phreatic levels, evaluates crack gages and inclinometers and provides reports to dam owners and the State Engineers Office. For emergency planning purposes ERC has modeled dam breach scenarios and prepared inundation mapping for use by local emergency managers. We have designed repairs to ancillary facilities including outlet works, the dam’s spillway and the headgate structure that diverts up to approximately 1,000 cfs into the Lake.

Project Categories:
irrigation

Swan River

Swan River Project

ERC was contracted by Summit County to complete a design/build restoration for an approximately one mile reach of the Upper Swan River. The Upper Swan River project area, a major tributary to the Blue River, had been historically mined using… Read more »

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Project Categories:
featured
stream-restoration

Swan River, Villas at Swan River

Swan River, Villas at Swan River

Summit County, CO

Sustained high flow events during the runoff season of 2011 resulted in significant erosion and lateral migration of the Swan River. This unchecked stream migration was threatening to undermine infrastructure and result in the loss of property at the Swan Villas development. ERC was retained to evaluate the potential for future flooding impacts, study the channel morphology and develop and construct improvements to protect the property. The project required moving the Swan River, which has a FEMA mapped floodplain, requiring that ERC ensure that the modifications would not result in a rise in the regulatory floodplain. Ultimate improvements along the 250 foot project reach incorporated moving the river back to its previous channel and construction of a structural rock foundation and cutoff that prevented further stream migration. All improvements were finished using native material and vegetation so that the end project was natural in appearance.

Project Categories:
stream-restoration

Sylvan Dale Ranch, Big Thompson River

Sylvan Dale Ranch

Loveland, CO

The Big Thompson was dramatically impacted by the floods of 2013. Situated at the mouth of the canyon, the Sylvan Dale Ranch property was particularly devastated by flood flows but also by the volume of sediment that was deposited during the event. ERC was contracted by the Big Thompson Watershed Coalition to restore the channel using a design/build approach. Work was required to improve watershed resiliency and protect vital infrastructure while improving flood conveyance, sediment transport, and aquatic and terrestrial habitat. Our design utilized natural channel concepts. A multi-stage channel that optimized habitat under low flows and accesses flood terraces was created. Riffle/pool/glide features were created within the channel to provide diversity and channel stability. Overbank grading was used to increase conveyance and protect structures. Where needed, banks were stabilized with a variety of techniques ranging from softer cobble toe protection to soil filled riprap planted with willows. Throughout the project, ERC complied with requirements of the DOLA process including Davis-Bacon wages, certified pay, postings, Section 3 reporting and employee interviews. The project was successful at restoring a heavily impacted river segment utilizing natural design principles.

Project Categories:
stream-restoration

Tarryall Creek

Tarryall Creek

Lazy River Ranch, Park County, CO

The Lazy River Ranch, located downstream of Tarryall Reservoir on Tarryall Creek had been impacted by years of land management practices and cattle grazing. As a result aquatic habitat was limited, bank erosion was actively occurring and riparian vegetation that is necessary to support a healthy stream system was largely absent. ERC was hired to improve the overall health of the stream and riparian system with the specific project goal of reducing sediment loading to the creek. ERC completed a design for this 7,700 foot reach that incorporated physical improvements such as bank stabilization, slope reductions in the floodprone area and revegetation of the riparian corridor for over 3,100 feet of bank protection. In addition to these physical improvements, land management suggestions on limited moving adjacent to the stream and confinement of cattle were included in ERC’s design.  Instream improvements included stabilizing the stream bed with soil filled grade control structures, creation of gravel riffles and construction of self-sustaining overwintering pool habitat.

Project Categories:
stream-restoration

Tenmile Creek Phases I and II

Tenmile Creek Phase

Summit County, CO

ERC was selected to restore a reach of Tenmile Creek that had been previously impacted by historic mining and other past land uses. The project, located on Forest Service property near the entrance to Copper Mountain Ski Resort, had been channelized and as a result was linear and entrenched and rarely able to access its historic floodplain. Design plans included returning the stream to a natural planform that included increasing the sinuosity from 1.05 to approximately 1.2 and creating repeating riffle/pool sequences over the 2,500 foot project reach. Design included development and construction of a natural channel liner to ensure the stream remained a gaining segment as this was critical to maintaining water rights in the area. The channelized stream channel that was abandoned when creating the meandering reach was converted to a wetland oxbow. Extensive riparian and upland reclamation was also undertaken as part of the overall system reclamation. After the success of the Phase I project, ERC completed the work as a design /build project.

Project Categories:
stream-restoration

The Perfect Drift Fly Fishing Club North Fork of the South Platte River

Perfect Drift Fly Fishing Club

Pine, CO 

The Perfect Drift is a private fishing club located along the North Fork of the South Platte River in Pine, CO. ERC was contacted by the club with the goal of optimizing trout habitat along a 4,000 foot stretch of the river, which was dominated by low-gradient riffles and generally lacking in habitat variety. This section of river is managed with the intent of providing club members with the opportunity to fly fish for trophy-sized trout. ERC’s design/build work reshaped the channel width to provide better habitat during low and high flow conditions. The stream’s profile was adjusted by creating repeating riffle/pool/glide sequences that added habitat variety and quality. Recreating these natural stream features enhanced the overall ecological health of the system by promoting macro-invertebrates projection and providing resting, spawning and forage habitat.

Project Categories:
stream-restoration

Town of Telluride – San Miguel River through Town

Town of Telluride - San Miguel River through Town

Telluride, CO

The San Miguel River runs through downtown Telluride. The Town of Telluride had past experience using a very structural approach in an attempt to enhance the San Miguel corridor. This structural approach was generally deemed unsuccessful as improvements didn’t fit into the aesthetic landscape of this high alpine valley and past work required continual maintenance. ERC was hired by the Town to complete a second phase of stream restoration using our natural restoration approach. The approximately 3,200 foot reach restored by ERC included areas that were immediately adjacent to private property and others that were more natural in character. The design accounted for the need to protect private property and ensure stability of the stream while incorporating improved aquatic and riparian habitat through the stream corridor. Work was completed so that the finished river system was natural in appearance and fit in with its surroundings.

Project Categories:
stream-restoration

Trapper Creek Habitat Improvements

Trapper Creek

Garfield County, CO

An existing population of native Colorado River Cutthroat Trout (Oncorhynchus clarkia pleuriticus) were discovered in Trapper Creek, located within the Roan Plateau. The population was monitored by Colorado Parks and Wildlife (CPS), Trout Unlimited and the BLM. Monitoring efforts showed that during extended drought conditions the population suffered significant losses due to limited pool habitat. ERC was selected to design and implement habitat improvements for the endangered cutthroat trout on Trapper Creek in the Roan Plateau. The project was constrained as heavy equipment could not be brought into this remote site. ERC evaluated innovative means to create deeper holding water pools for the cutthroat trout. The final design, which is intended to be a pilot project for potential future improvements, included an array of hand constructed riffles, bend pools and drop structures on an approximately 4,700 foot stretch of stream. All features were field fit based on site specific conditions which included near surface bedrock and highly weathered shale in various locations. All improvements were installed by ERC as a design/build project. The long-term performance of the different features will be evaluated to better understand techniques that are most suited for future work.

Project Categories:
stream-restoration

Trout Creek Stream Assessment

Trout Creek Stream Assessment

Peabody Coal’s planned Trout Creek reservoir would alter the flow regime, sediment conveyance and stream conditions in Trout Creek. ERC was hired as part of the FERC process to evaluate baseline stream conditions and assess potential impacts of the planned on-line dam. Field work included stream classification, cross sectional and longitudinal stream surveys, pebble counts, suspended and bedload sediment sampling and bank stability characterization. Using this exiting conditions data, ERC projected sediment inflows to the reservoir and changes in sediment conveyance and channel morphology that could be expected to occur as a result of the dam.

Project Categories:
stream-assessments

Udall Treatment Wetland

Udall Wetland

The City of Ft. Collins was concerned about the water quality from developed land that runs off directly into the Poudre River. Nuisance or low flow conditions were of particular concern. ERC designed and constructed a 2-acre treatment wetland to intercept and filter flows before their release to the river. The wetland system included a staged hydraulic control feature that routes lower flows through the treatment wetland while allowing peak storm flows to bypass the wetland. ERC’s design included a soil matrix and natural vegetation for biofiltering, fine sediment removal and uptake of pollutants. The wetland provided the secondary benefit of creating wildlife habitat along the river corridor.

Project Categories:
environmental

Uncompahgre River Aquatic Habitat Improvements, Phases I and II

Uncompahgre River Aquatic Habitat

Montrose, CO

The Uncompahgre River through downtown Montrose has been impacted by past land encroachment, channelization and flood proofing measures. The City of Montrose desired to improve the riverine corridor and enhance aquatic habitat, stabilize river banks and improve terrestrial habitat along this heavily utilized corridor. ERC was retained to complete design, permitting and construction of these improvements for a 6,600 foot stretch of river. Improvements included creation of variable types of habitat long the project reach. Natural features such as riffle/pools and bend pools were created, but the project also included significant work to protect public and private lands as well as public infrastructure and irrigation facilities. Phase I of the project was constructed by ERC in 2006 and Phase II was completed during 2013/2014.

Project Categories:
stream-restoration

Windy Gap Firming Project EIS

Windy Gap Firming Project EIS

ERC was the surface water resource specialist tasked with developing a model of the Colorado – Big Thompson (C-BT) and Windy Gap systems to evaluate the integrated operations of those projects and analyze the firm yield and hydrologic effects associated with Windy Gap Firming Project (WGFP) EIS alternatives. ERC used the State of Colorado’s CDSS model and BESTSM (a surface water allocation model) to develop an integrated WGFP model capable of simulating the C-BT and Windy Gap systems and Colorado and South Platte River basins. ERC configured the WGFP model to represent each of the EIS alternatives and simulated the model to generate hydrologic output.  ERC used the model to perform an assessment of Windy Gap water rights, including projected diversions under the EIS alternatives and the effects on other water rights and streamflows in the Colorado River and South Platte River basins. ERC used model output to complete the surface water impacts analysis and associated sections of the EIS document and support evaluations of resources affected by changes in flow and reservoir contents including wildlife, aquatic resources, recreation, stream channel morphology, wetlands and riparian habitat, floodplains, and water quality.

Project Categories:
water-resource-planning

Yampa River at Fournier Park Phases I and II

Yampa River at Fournier Park Phases I and I

Steamboat Springs, CO

The City of Steamboat Springs acquired an approximately 1,400 foot stretch of the Yampa River and adjacent lands for the purpose of enhancing public access and river recreation. This stream section, however, was prone to lateral streambank migration and suffered losses of up to 25 feet of bank per year. ERC was retained by the City to restore this stretch of the Yampa to a more natural state while mitigating existing bank instability. ERC’s design reshaped the entire 1,400 section, creating two natural riffle/pool sequences as part of reestablishing a stable stream planview and profile. Imported rock was used to define the shape of the active channel and buried below the eroding bank to create a structural control to mitigate lateral migration. All imported rock was covered with native sands, gravels and cobbles to hide the structural fill material and provide the stream with a natural appearance. Native vegetation was then added to reestablish the riparian fringe and provide additional bank stability.

Project Categories:
stream-restoration

Yampa River Master Plan

Yampa River Master Plan

Steamboat Springs, CO

The Yampa River through the City of Steamboat Springs is a prized amenity attracting thousands of visitors for active and passive recreation.  However, this popularity was creating a negative impact to the riparian corridor and conflict amongst the variety of users. ERC was hired by the City of Steamboat Springs to develop a Yampa River Master Plan to provide a framework for instream and riparian area improvements to optimize the recreational benefits of the Yampa River while protecting its ecological integrity. The plan covered the river and adjacent property on City owned and controlled property (6.4 miles) along the Yampa River.  The plan prioritized recommended improvements and provided budgetary cost estimates for City implementation.

ERC hosted multiple public meetings where the technical, administrated and operations and maintenance issues associated with the current river and proposed improvements were discussed. This public input, combined with river reconnaissance performed by ERC and the results of past studies, was the basis for the identification of seven separate River Management Areas (RMAs). Each RMA represents a portion of the river where management priorities such as recreation, flood protection and natural restoration objectives may differ. Within these seven RMAs a combined total of 86 individual areas for restoration were identified. Community input and ERC’s technical evaluation were used to rank the relative priority of each of the improvement areas. Conceptual level designs were developed for each of the 86 improvement areas, which were then used to estimate the budgetary costs required for all proposed improvements. In total the defined improvements were estimated to cost over $5.1 million in 2008 dollars. The City has since used the Master Plan to assist in fundraising and has completed many of the individual restoration improvements identified in the Master Plan.

Project Categories:
stream-restoration