What Follum Hydrologic Solutions, LLC does

Follum Hydrologic Solutions, LLC is a boutique hydrologic and geospatial consulting firm founded in August 2021 by Mike and Tara Follum and headquartered in Casper, Wyoming. The firm delivers cold-region hydrology, continental-scale flood modeling, and military mobility planning services, with applied emphasis on data-sparse and ungaged watersheds. Its technical stack spans HEC-RAS 2D, HEC-HMS, RAPID, ARC (Automated Routing Controller), FloodSpreader, GSSHA, AdH, RiverWare, AutoRoute, and Python-based utilities, supplemented by ensemble forecasting workflows (e.g., 21-member weather ensembles) and integration with the GEOGLOWS global hydrologic forecasting framework. Proprietary methods include the RTI snow method, ModCFGI, and the Gap Analysis Tool (GAT) developed for the U.S. Army ERDC.

The firm's revenue model is professional services: project-based consulting and subcontracting delivered primarily to federal and state government agencies, with engagements spanning the U.S. Army Engineer Research and Development Center (ERDC), Wyoming State Engineer's Office, Wyoming Water Development Office, Bureau of Reclamation, Utah Division of Water Resources, Trout Unlimited, and BYU. The team is composed of six doctoral-level engineers with prior federal-agency experience at ERDC, Bureau of Reclamation, NOAA, and Army Corps, supported by an engineering intern; multiple staff hold or have held credentials relevant to military mobility work. Geographic engagements referenced include Wyoming, Utah, Puerto Rico, South America, and the Sava River Basin.

Strategically, the firm has converted subcontract relationships into permanent capacity (Mark Wahl, PhD, full-time in 2023), extended its reach into global hydrologic forecasting via the August 2024 hire of GEOGLOWS Technical Director Riley Hales, and embedded its tools inside the BYU/CIROH National Water Model Flood Inundation Mapping ecosystem. UCRAF-DST has expanded from Wyoming into Utah, and tools such as GAT and ARC position the firm to productize federal hydrologic assets beyond pure time-and-materials consulting. The firm is bootstrapped and founder-owned with no outside capital disclosed.

Name

Follum Hydrologic Solutions, LLC

Legal name

Follum Hydrologic Solutions, LLC

Website

https://follumhydro.com

Company type

Private

Founded year

2021

Operating status

Operating

Headcount range

1–10 employees

Short description

Follum Hydrologic Solutions is a Casper, Wyoming-based boutique consulting firm specializing in cold-region hydrology, flood modeling, and military mobility planning, serving federal and state government agencies including U.S. Army ERDC, Bureau of Reclamation, and Wyoming water offices.

Ownership category

akta.pro rank

Product category

Hydrology & Water Resources Consulting

NAICS

Scientific Research and Development Services (5417)

SIC

Water Supply (4941)

akta.pro primary industry

Water Resources, WASH & Integrated Water Management (BPADALAH)

Keywords

• Hydrologic consulting services
• Flood inundation mapping
• Water resources engineering
• Geospatial analysis services
• Cold region hydrology

Headquarters

HQ city

Casper

HQ country

United States

HQ region

North America

Offices1 record

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Technology or R&D, Operations, Marketing or Sales, Others

Revenue model

1. Government Consulting Contracts: Professional hydrologic and geospatial consulting services provided under contract to federal and state government agencies including U.S. Army ERDC, Wyoming State Engineer's Office, Bureau of Reclamation, and others. Revenue is project-based, secured through direct contracts and subcontracting arrangements.

Go-to-market motion1 record

Distribution channels1 record

Core offering

Follum Hydrologic Solutions (FHS) is a hydrology and geospatial consulting firm providing professional services in flood inundation mapping, water resources analysis, cold region hydrology, and military mobility hydrology. The firm develops and applies proprietary tools such as AutoRoute, RAPID, the Automated Rating Curve (ARC) framework, the Gap Analysis Tool (GAT), and DEM_Cleaner to deliver regional to continental-scale modeling, water accounting, and rapid-response flood products for government clients.

Product overview

Follum Hydrologic Solutions (FHS) is a hydrology and geospatial consulting firm that provides innovative solutions to hydrologic and geospatial problems. The company's portfolio centers on flood inundation mapping and hydrologic modeling tools developed for military and civil applications. The core tools include the Gap Analysis Tool (GAT) for tactical bridge planning, the Automated Rating Curve (ARC) framework for generating hydraulic variables, DEM_Cleaner for topobathymetric surface preparation, AutoRoute and FloodSpreader for regional-scale flood mapping, and a Multi-Model Flood Mapping Framework supporting FloodSpreader, FIST, and Curve2Flood models. Supporting tools include the Diversion Runoff Calculator (DRC) for water accounting, Snow and Frozen Ground Simulations using RTI and ModCFGI methods, and various terrain/DEM processing tools. These products work together as an integrated workflow: data preprocessing tools (DEM_Cleaner, land cover creation, stream cleaner) feed into hydraulic modeling frameworks (ARC, AutoRoute, FloodSpreader), which then support applications in military mobility analysis, infrastructure planning, and flood forecasting. FHS also offers consulting services including Post-Fire Hydrology, Instream Flow Analysis, Transit Loss Studies, and Water Quality Modeling.

Differentiator

Problem solved

Functional benefit

Products and services

• Gap Analysis Tool (GAT) A Python-based, GIS-integrated application that automates identification and characterization of wet-gap obstacles (rivers, streams, channels) for military mobility and tactical bridge planning. Developed for the U.S. Army ERDC.
• AutoRoute Flood Inundation Model Regional-scale flood mapping tool that produces raster flood inundation maps from peak flow inputs across low-, medium-, and high-flow scenarios at regional to continental scales.
• Automated Rating Curve (ARC) Framework Framework that generates spatially distributed depth and water surface elevation estimates used as common inputs across multiple flood mapping models including FloodSpreader, FIST, and Curve2Flood.
• AutoRAPID Coupled Model System Coupled RAPID (Routing Application for Parallel computation of Discharge) and AutoRoute models for rapid flow and flood-inundation estimation over large spatial extents, demonstrated on the Mississippi River Basin (1.2 million river reaches).
• Multi-Model Flood Mapping Framework Open, modular methodology that converts large-scale streamflow forecasts into flood inundation maps using FloodSpreader, FIST, and Curve2Flood in a multi-model approach rather than single deterministic output.
• DEM_Cleaner Preprocessing Tool Preprocessing tool that transforms digital elevation models into hydraulically consistent topobathymetric surfaces using baseflow streamflow data, correcting non-physical water surface artifacts.
• Ensemble Flood Maps Methodology to create ensemble flood maps for continental-scale forecasting using 21-member weather/flow ensembles to represent uncertainty in flood extents.
• Diversion Runoff Calculator (DRC) Tool for estimating agricultural water consumption and diversion runoff calculations used across the Colorado River Basin in Utah for irrigation water accounting.
• Snow and Frozen Ground Simulations Hydrologic modeling service using the Radiation-Derived Temperature Index (RTI) snow method and Modified Continuous Frozen Ground Index (ModCFGI) method to simulate snowpack and frozen ground with minimal data. Implemented in GSSHA and HEC-HMS.
• Post-Fire Hydrology Services Consulting services analyzing post-wildfire hydrologic response including increased runoff, debris flow, and flood risk for land management agencies.
• Instream Flow Analysis Consulting service conducting Level I instream flow studies and feasibility analyses to support water rights administration and ecological flow requirements.
• Transit Loss Studies Consulting service quantifying water transit losses in river systems using RiverWare modeling to support interstate water compact accounting for the Wyoming State Engineer's Office.
• Water Quality Modeling Review Independent technical review of water quality modeling (CE-QUAL-W2) for reservoir and pumped storage projects, providing recommendations for environmental analysis and permitting.
• Topobathymetric Estimation Services Service generating topobathymetric datasets suitable for 2D hydraulic models by estimating channel bathymetry from readily available baseflow streamflow data.
• Hydrology for Mobility Analysis Service integrating operational hydrology data with military mobility analysis to create Go/No-Go maps for multiple vehicle types, developed with ERDC Geotechnical and Structures Laboratory.

Quantifiable outcome

• AutoRoute model improvement: average F value increase of 17.5% for low-flow events and simulation time reduced by over 40%
• +2 more outcomes

Named customers6 records

Segments3 records

Ideal customer profiles3 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature9 records

Partnerships

Four partnerships are on record, tiered core and minor.

• Precision Water Resources Engineering (PWRE)coreStrategic or Co-development PartnerCollaborative partnership on Green River Basin Transit Loss Evaluation for Wyoming State Engineer's Office. FHS worked with PWRE to complete comprehensive transit loss evaluation. PWRE serves as prime contractor with FHS as collaborator on water balance analysis and RiverWare modeling.
• Brigham Young UniversitycoreStrategic or Co-development PartnerTeaming with BYU under CIROH-funded research to expand National Water Model Flood Inundation Mapping framework for infrastructure impact assessment. Integrates FHS's open-source ARC and Curve2Flood tools into CIROH FIM ecosystem.
• Trout UnlimitedminorStrategic or Co-development PartnerEngaged by Trout Unlimited to conduct independent technical review of water quality modeling for proposed Seminoe Pumped Storage Project. FHS examined CE-QUAL-W2 model and provided recommendations for environmental analysis and permitting.
• Utah Division of Water ResourcescoreStrategic or Co-development PartnerAs subcontractor to PWRE, expanding Utah Colorado River Accounting and Forecasting Decision Support Tool (UCRAF-DST) to additional watersheds in Upper Colorado River Basin. Provides DRC models and hydrologic datasets for RiverWare modeling.

Scale indicators3 records

Recent moves6 records

Expansion highlights6 records

Direct peers

• RESPEC: Engineering and water resources consulting firm with federal agency work, comparable to FHS in applied hydrology, geospatial services, and government client mix.
• INTERA Incorporated: Water resources and geosciences consulting firm with deep federal agency relationships, offering hydrologic modeling and groundwater services comparable to FHS's transit loss and water balance work.
• Riverside Technology, Inc. Water resources modeling and consulting firm based in Colorado with deep federal hydrology expertise, directly comparable to FHS in technical offerings and customer profile.
• Lynker: Water science and engineering consulting firm with strong federal hydrology focus, comparable to FHS in size, mission alignment, and federal contract base including NOAA and USGS work.

Broad incumbents

• HDR Inc. Engineering firm with a strong water resources practice serving federal agencies, offering comparable hydrologic modeling and floodplain analysis as part of broader infrastructure services.
• AECOM: Global engineering and infrastructure firm with substantial water practice serving federal agencies, comparable in hydrology services but operating at vastly greater scale.
• Tetra Tech: Large environmental and water resources consulting firm with extensive federal contract portfolio, offering overlapping flood mapping and hydrologic modeling capabilities as part of a much broader portfolio.
• WSP: Large engineering consultancy with environmental and water resources practices serving government clients, comparable in federal hydrology work but operating at much greater scale and breadth.
• Stantec: Global engineering and environmental consulting firm with water resources practice, serving similar federal and state agency clients with broader capabilities than FHS's specialty focus.
• Jacobs Solutions: Large engineering and consulting firm with deep water resources and federal hydrology practices, competing for the same federal contracts as FHS but with broader service offerings.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat4 records

Key risks7 records

Key highlights7 records

Customer concentration

• LinkedInlinkedin.com/company/follum-hydrologic-solutions-llc

Revenue estimate

Valuation estimate

Number of profiles

Profiles8 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Follum Hydrologic Solutions, LLC