MetStat’s team of hydrometeorological experts is currently involved in a number of different projects that include risk-based precipitation frequency analyses, storm analyses, and site-specific probable maximum precipitation assessments, to name a few. A sample of major current projects follows below.
Wind Data Analysis for Wave Run-Up Study at Alcona Dam
MetStat produced wind-frequency estimates for a reservoir above Alcona Dam in Michigan to support a Wave Run-up Study being conducted by Barr Engineering for Consumers Energy as part of a Federal Energy Regulatory Commission (FERC) Risk Informed Decision Making (RIDM) Pilot Study. The purpose of the overall analysis was to estimate wave run-up as it pertains to potential failure modes. Of primary interest were winds from the northerly direction that impact the dam during and after Mid-Latitude Cyclone storms. We identified the annual maximum wind speeds for a 1-hour duration from the dominant direction for different storm types/days and produced wind-frequency estimates out to a 1 in 1,000 annual exceedance probability and seasonal histograms. Additionally, we provided a wind climatology summary and anecdotal examples of winds during Mid-Latitude Cyclone storm events.
72-Hour Precipitation Frequency Analysis for Tropical Storms in South Carolina
To support Duke Energy’s Focused Evaluation and Integrated Assessment, MetStat and MGS Engineering developed the watershed-specific precipitation frequency relationship for the controlling 72-hour storm type applicable to the Black Creek watershed above the Robinson Nuclear Plant in South Carolina. After evaluating the controlling storm type as Tropical Storms and Remnants, we developed estimates that extend to the equivalent annual exceedance probability (AEP) of the 72-hour probable maximum precipitation (PMP). Deliverables included scalable temporal and spatial storm templates. Coupling the templates with the precipitation-frequency results, a HEC-HMS hydrologic model can be initialized with plausible, synthetic storm events for computing a series of hydrologic hazard curves.
Simplified Stochastic Event Flood Modeling of Alcona Dam in Michigan
Partnered with Barr Engineering Co., MetStat provided critical spatial and temporal storm precipitation and temperature information for use in erosion/dam breach modeling, calculating the hydrologic hazard curve of peak inflows to the Alcona Dam reservoir, and flood routing and inundation modeling. As a part of this study, we performed a historical storm review, storm seasonality analysis, selected a sample of storms for analysis, and transposed the storm templates to the Au Sable River watershed.
Trinity River Basin Extreme Precipitation Project
Hydrologic Hazards Development, Trinity River Basin Extreme Precipitation Project for the U.S. Army Corps of Engineers (USACE)
MetStat, partnered with MGS Engineering, is analyzing extreme storms and regional precipitation-frequency for USACE Dam Safety Program’s Hydrologic Hazards Team (HHT). For this project, we are providing spatial and temporal data of extreme storms to be used for hydrologic modeling and calibration. We are also conducting precipitation-frequency analyses on different storm types (Mid-Latitude Cyclones, Mesoscale Storms with Embedded Convection, Local Storms and Tropical Storm Remnant Storms) that will be used to conduct stochastic modeling for floods generated by the various storm types to develop hydrologic hazard curves.
Colorado-New Mexico Regional Extreme Precipitation Study
MetStat, partnered with MGS Engineering, is conducting a Regional Precipitation-Frequency Analysis for the Colorado Water Conservation Board, the Colorado Division of Water Resources and the New Mexico Office of the State Engineer as part of their Regional Extreme Precipitation Study. MetStat uses various temporal, spatial and meteorological characteristics to differentiate between storm types and then conducts an L-moment regional precipitation frequency analysis on each. The resulting grids of precipitation frequency estimates will be used to conduct stochastic modeling for floods generated by the various storm types and to develop hydrologic hazard curves for risk-based analyses.
BC Hydro Upper Columbia River Extreme Floods
MetStat® is proud to partner with MGS Engineering Consultants, Inc. on the Stochastic Modelling of Extreme Floods for BC Hydro Seven Dams on the Upper Columbia River System project for British Columbia Hydro and Power Authority (BC Hydro). We are conducting precipitation-frequency analysis, assessing the seasonality of extreme events, generating historical storm spatial and temporal patterns for Mid-Latitude Cyclones, providing snow model parameters (freezing level and surface temperatures), and developing inputs to the Stochastic Event Flood Model (SEFM) for dam safety risk analyses.
Bear River Site-Specific Probable Maximum Precipitation (PMP)
MetStat® is currently working on a site-specific probable maximum precipitation (PMP) study for the Bear River Drainage Basin in northern Utah and southern Idaho, in support of an update to the Bear River Hydroelectric Project Hazards Study for PacifiCorp’s dam safety program. Specifically, PMP results determined by the innovative Enhanced Storm Transposition Procedure (ESTP) will be provided for the drainage basins above each of the four dams on the lower Bear River in Idaho and Utah: Soda, Grace, Oneida, and Cutler Dams. These results will be used by WEST Consultants, Inc. to compute the probable maximum flood at the four dam locations.
Tennessee Valley Authority Hydrologic Hazards Assessment
Southern California Edison Hydrologic Risk Assessment
This multifaceted project involves examining hydrologic risk at Southern California Edison flood control structures on both short- and long-term scales. Notably, this project also includes a climate change evaluation. The Coupled Model Intercomparison Project phase 5, Bias-Correction Spatial Disaggregation technique (CMIP5-BCSD) climate model data is used to generate adjustment factors for the hydrometeorological inputs to the Stochastic Event Flood Model (SEFM), for the 50-year period from 2020-2069. Two climate scenarios are used during the time period: hot-dry and warm-wet. The hot-dry scenario represents the greatest influence on snowpack reduction and reduced water availability; the warm-wet scenario represents the least reduction in snowpack and increased water availability. Adjustment factors from each scenario are applied to SEFM templates to update the hydrologic frequency estimates for a watershed of interest.
Precipitation Storm Analyses for Maricopa County Flood Control District
Since 2010, MetStat® has provided the Flood Control District of Maricopa County with detailed, precision storm precipitation analyses for use in hydrologic modeling projects.
Consolidation and Enhancement of Hydrologic Model Parameter Estimation Tools
MetStat conducted a consolidation and enhancement of the IHABBS (Integrated Hydrologic Automated Basin Boundary System) hydrologic model parameter estimation tool in 2015-2016. IHABBS provides National Weather Service hydrologists with tools for automatically delineating, editing, displaying, querying, and managing hydrologic basin boundaries. This NOAA-funded project created a modern GIS Toolbox that can be run seamlessly from the RFC’s ArcGIS implementation to aid in hydrologic model calibration and development. MetStat’s modernization efforts included integrating more up-to-date datasets and increased flexibility for users and specifically pertained to the following improvements:
- Integration of NHD Plus V2 data for basin delineation
- “Rapid” tool for multiple watersheds
- CAP Tool integrates updated PRISM climatology grids and 10-m NED DEM
- SNOW-17 ADC Tool developed using SNODAS SWE (snow water equivalent) and computed AESC (areal extent of snow cover)
- Pre-generated archive of daily, 3-day, and Jan-Aug subsets of SWE/AESC
The project concluded with the development of a user’s guide and on-site training at the CNRFC in Sacramento, CA in April 2016.