Solution specific articles for Water & Environmental Resources.

Lower Poudre River Flood Recovery and Resilience Master Plan

In response to the devastating flood of September 2013, the Coalition for the Poudre River Watershed (CPRW) hired Lynker to develop a flood recovery and resilience master plan for the Lower Poudre River. The project was funded by a grant from the Colorado Department of Local Affairs (DOLA) Community Development Block Grant Disaster Recovery (CDBG-DR) Resilience Planning program.

The master planning effort combined scientific and engineering analysis with community collaboration to identify and prioritize opportunities to improve river resilience and river health. Components of the master plan include reach-by-reach analyses of changes to the historical channel, assessments of geomorphological and ecological values, identification of vulnerabilities, and sediment transport modeling. Lynker led a team of scientists, engineers, geomorphologists, ecologists, modelers and designers from Otak, AlpineEco and LVBrown Studio to create an informative, user-friendly master plan that provided recommendations through the project area.

A sediment transport model was built for the 36 miles of river in the project area, utilizing existing HEC-RAS model cross-sections to determine sediment transport capacity on a reach-by-reach basis. The model focused on the use of total effectiveness, which uses the river flow regime and their respective probability of occurrence to determine the river’s total sediment transport potential over time. Sediment bed samples were collected by performing pebble counts at pre-determined reach cross-sections. Each field visit was thoroughly documented with field data sheets and photos from a GPS camera.

The data collected for the project was used to compile a reach-by-reach river characterization and assessment to determine areas with the greatest need for future restoration work. The assessment included metrics for flood hazards, geomorphology, ecological and aquatic habitat, social vulnerability and local priorities. For instance, the project steering committee and the local community put a high emphasis on the integrity of the Poudre River Trail, a 21-mile paved path the closely follows the river for much of the project area. Therefore, the Poudre River Trail was included as an element of river assessment and the final Poudre River prioritization scoring.

The large project area showcased Lynker’s ability to develop river restoration projects through community outreach and adaptive priorities. The planning process included an extensive public outreach effort that drew on landowners and local community experiences to pinpoint vulnerable areas and important assets. Based on these meetings, a cultural aspect of the community was accounted for when developing restoration projects. Illustrative conceptual designs were developed for the high priority reaches while taking into consideration ongoing projects within the reaches. The master plan and sediment model developed for the Lower Poudre are intended to be continuously evaluated during future planning actions or assessments to make reach-scale decisions that can help inform the solutions that may be best for a reach.

NNDWR Gauge Network Optimization

The Navajo Nation Department of Water Resources (NNDWR) manages a network of rain cans, automated climate stations, stream gauges and snow monitoring gauges (both Snow Courses and SNOTEL sites).  The majority of these stations must be visited on a monthly basis by NNDWR staff to gather data and inspect the gauges for damage.  Nationwide budgetary constraints have forced the NNDWR to re-evaluate its gauge network to reduce field costs.

Lynker was hired to reduce the field effort required to maintain the NNDWR gauge network while optimizing the network’s ability to accurately predict rainfall across the entire Navajo Nation. At the project start, there were more than 110 stations that require regular visits across 27,000 sqmi of land, requiring a very large amount of monthly field work to visit, maintain and collect data from all the stations. The project team implemented an ArcGIS model to reduce by 30% the monthly field hours required to visit and monitor the rain gauge network while minimizing the measurement error introduced to the system by the removal of gages.

The impact of an increase in measurement error is best described in terms of the water that is “missed” as a result of the removal of a gauge.  The Volumetric Index of the Error of Water (VIEW) is the error in measurement multiplied by the average precipitation at any given grid cell.  The average precipitation used was the PRISM 30-year annual average dataset.

With a stringent requirement for field effort reduction, the primary means of network optimization was the removal of tipping bucket rain gauges.  A combination of factors led to the creation of optimized network test cases; gauge period of record, clustering with other gauges, rainfall measurement coverage within individual watersheds, and a qualitative evaluation by NNDWR staff of data quality and potential for vandalism at the gauge site.

Automated climate gauging stations were recommended to either be connected to the central NNDWR office through radio or cellular telemetry or were removed altogether to offset the high associated maintenance cost.  To improve precipitation prediction, scripted connections were created to existing data sources such as the NOAA-COOP rainfall network so the NNDWR could benefit from easy access to that data.

Reservoir and Irrigation District Water Supply Study

Lynker Technologies worked with a confidential client to provide water resources planning services in Western Europe. This work involved extensive collection and processing of rainfall, climate and hydrologic data from various European agencies. Once data collection was complete, Lynker developed a set of impacted future conditions under an ensemble of climate change projections. The hydrometeorological data as well as the future climate conditions were used to develop a water resources model to test different combinations of hydrology, water consumption, system operations and legal frameworks. Output from the model was used to provide the client with decision support for planning and infrastructure investment.

Projecting Climate Change Impacts to Extreme Temperature and Precipitation for Denver Water’s Infrastructure

Lynker worked with Denver Water, the University of Colorado and NCAR/UCAR staff to review a range of standard methods for characterizing future extreme precipitation and temperature events under climate change. The methods reviewed include downscaling projects like LOCA, MACA, BCSD and the CORDEX archive as well as point downscaling statistical approaches. This work involved both an extensive literature review covering the foundations of the methods as well as independent assessments of results from each method.  Once the literature review was complete, Lynker performed detailed statistical analyses to help Denver Water understand increases in frequency and intensity of extreme rainfall and heat events at a large set of locations.

California Ranch Climate Change Assessment

A climate-change impact analysis was completed for a confidential client in California. The purpose of the study was to provide climate-impacted hydrology (streamflow, irrigation water demand) for a future planning horizon. Our team provided a low-cost solution by utilizing existing Bureau of Reclamation (USBR) Coupled Model Intercomparison Project (CMIP5) climate change runs processed through the Variable Infiltration Capacity (VIC) hydrologic model. The future climate-impacted hydrology from 2020-2049 (streamflow, evapotranspiration) was compared to a baseline hydrology from 1970-1999, to determine a monthly set of “change factors” for water supply and water demand (streamflow and irrigation water demand, respectively). The change factors were applied to the historical hydrology datasets to create climate-adjusted timeseries for streamflow and water demand, which were used to evaluate future water supply conditions.

Lynker leads project on Snake River Plain Aquifer System

The Eastern Snake Plain region of Idaho produces approximately 21 percent of the state’s goods and services, resulting in an estimated value of $10 billion annually, and water is the critical element in the region’s productivity. The development of both groundwater and surface-water water use across the Eastern Snake Plain has led to conjunctive management of the common water resource. In an on-going contract with the Idaho Ground Water Appropriators (IGWA), Lynker provides oversight on both development of a regional groundwater model of the Eastern Snake Plain Aquifer (ESPAM) and its application in water resource management. ESPAM is a groundwater model developed by the State of Idaho as a tool to help quantify the impacts of current water use practices and/or proposed alternatives on the common water resource of the State across the Eastern Snake Plain.

Over the course of the multi-year, multi-task relationship, Lynker has provided the following services to the groundwater appropriators: water rights and expert witness support, groundwater modeling, conjunctive used analysis, consumptive use modeling, development and review of mitigation plans, and hydrologic baseline and historical water use analysis.

Mount Werner Water & Sanitation Macarthur/Yampa Meadows Alluvial Aquifer Investigation

Under contract with Mount Werner Water & Sanitation, Lynker was tasked with hydrologic and hydrogeologic data review and compilation for model inputs and framework development of a Yampa River alluvial aquifer MODFLOW model. Analysis included detailing the geographic and climatic setting and quantifying surface water groundwater interactions based on observed surface water and groundwater trends, aquifer testing of alluvial properties, and groundwater modeling. Modeling analysis included discretizing Yampa river channel geometry, developing streamflow records for model calibration, developing an annual water budget for the system, defining aquifer geometry and properties, and quantifying streambed conductance and associated accretions and depletions to the Yampa River and other surface water features.

The groundwater modeling analysis was used to assess present and potential future production from the alluvial aquifer infiltration galleries, quantify associated impacts to surface water features, and defining a capture zone to protect against water contamination concerns.

 

Drought Resilience Modeling – Stochastic Hydrology Modeling

United Utilities in the United Kingdom requested cutting-edge water resources modeling to more fully understand its water supply, especially as it relates to improving drought resilience. Lynker Technologies deployed a two-part stochastic simulation technique to model both the inter-annual flow sequences using a non-homogeneous Markov Chain (NHMC) model and the intra-annual variability using a k-nearest neighbor (KNN) nonparametric method. The flow simulation was performed simultaneously at four gauge locations so that the water system could be analyzed together as it is operated by the client.

The final output was 5,000 years of simulated streamflow at a daily timestep, which preserved spatial correlation between the sites, decadal variability of the streamflow, and seasonal trends while using empirically-based methods. The simulated streamflow data greatly expanded upon the 50-year observed record, which provides improved estimates of for instance the 100-year drought recurrence interval.

 

Modeling Analysis of a Tailings Storage Facility Dam Breach for the Proposed Pebble Mine

In an effort to provide the public with relevant information during the DEIS public comment period, Lynker undertook a modeling study to estimate the downstream impacts of a Tailings Storage Facility failure, if it were to occur.

Lynker used publicly available data describing the physiography and hydrology of the region, and data published by PLP describing the proposed TSF design and other mine site characteristics, to build a model of tailings release and downstream transport. Lynker developed our model using the FLO-2D software package, one of the few flood modeling packages capable of simulating the non-Newtonian flows that characterize tailings failures, and one that is commonly utilized by the mining industry for similar purposes (e.g., Knight Piesold, 2014; TetraTech, 2015).

Lynker used a comprehensive sensitivity analysis to evaluate how outcomes vary with different model parameters, and developed a set of failure scenarios to bracket the range of potential downstream impacts for different release volumes and durations. Our results provide regulators and the public with information that will be valuable during the public comment period for the DEIS.

Runoff Risk Guidance Tool to Mitigate the Water Quality Impacts of Nutrient Application

Lynker assisted the NOAA National Weather Service (NWS) North Central River Forecast Center (NCRFC) develop an enhanced Runoff Risk Guidance capability using the NWS Distributed Hydrologic Model. This project developed and implemented a multi-agency collaborative Runoff Risk Advisory Forecast (RRAF) tool for manure producers and nutrient applicators in multiple states that provides a dynamic, real-time model-based decision support tool for farmers and land managers to help with short-term application decisions.

Farmers often apply manure and nutrients to fields at times dictated as much by factors such as farming schedules and manure storage capacity than simply by when the plants need them. This often leads to poorly timed applications. Application prior to a rainfall-runoff event might mobilize nutrients to the hillslope and channel and away from where they are needed, resulting in detrimental impacts on water quality such as algal blooms and hypoxia, and at spatial scales from the contamination of local drinking wells to fish kills in the Great Lakes and Gulf of Mexico. Getting the timing right for application of nutrients is key in this regard. Specifically, it is critical to not apply nutrients before heavy rain or anticipated snowmelt which could carry nutrients right off the fields and into nearby water bodies.

Lynker helped develop and then enhance the RRAF by integrating, testing and validating the higher resolution distributed hydrologic model, thus enabling assessments of risk to be conducted at a finer spatial scale. Lynker also worked on RRAF stakeholder outreach and training. The project has helped NWS meet its Weather-Ready Nation mission of improving and expanding decision support services to a wide array of decision-makers and leveraging its capabilities into new areas such as water quality across the entire hydrologic spectrum ranging from local streams to oceans.