itwh

What itwh does

ITWH GmbH (Institut für technisch-wissenschaftliche Hydrologie GmbH) is a German software and engineering company founded in 1990 and headquartered in Hannover, with 51–100 employees, specializing in urban hydrology, sewer network simulation, and rainwater management. The company sells a portfolio of Windows desktop software — including the flagship hydrodynamic sewer simulation tool HYSTEM-EXTRAN, the long-term rainwater treatment simulator KOSIM, the CAD-integrated drainage planner GIPS, the ArcGIS-based sewer network modeler FOG Pro, the radar rainfall visualization platform NVIS, the heavy precipitation statistics tool itwh KOSTRA-DWD 2020, the LAWA-authorized extreme precipitation database PEN-LAWA 2010, and a family of Excel-based RW-Tools planning assistants — to engineering consultancies, municipalities, and municipal utilities (Stadtwerke) in the DACH region. Its products are explicitly built around German regulatory frameworks (DWA worksheets, DIN standards) and are integrated with industry-standard platforms including Esri ArcGIS, AutoCAD, and BricsCAD, as well as with authoritative national precipitation data from the Deutscher Wetterdienst (DWD) and LAWA-commissioned datasets.

Underlying technology centers on deterministic numerical hydrology and hydraulics models rather than AI, with proprietary engines for coupled surface runoff and pipe network simulation, model rain generation (EULER), GIS-based sewer network modeling, and radar data correction. The company holds a described market-leadership position for real-time control (RTC) systems in the German Smart City sector and is LAWA's commissioned developer for the PEN-LAWA 2010 extreme precipitation database.

The business model is dominated by one-time perpetual software license sales (single-seat and network licenses, with follow-up license discounts of ~25%) at modest price points — EUR 450 for KOSTRA-DWD, EUR 500 for PEN-LAWA, EUR 4,000 for NVIS — supplemented by professional services revenue from engineering consulting and planning, custom software development, paid training courses (transitioned to live-online delivery in June 2025), and an emerging subscription-style web data services stream through the NVIS-Web portal. Distribution is direct via the company website (itwh.de), with software support handled through FAQ, downloadable patches, and TeamViewer-based remote assistance; marketing relies on the corporate website, a YouTube channel, and email newsletter, with no public API or SDK offered.

Name

itwh

Legal name

Institut für technisch-wissenschaftliche Hydrologie GmbH

Website

https://itwh.de

Company type

Private

Founded year

1990

Operating status

Operating

Headcount range

51–100 employees

Short description

ITWH GmbH is a German software and engineering firm that develops specialized desktop and web software for urban hydrology, sewer network simulation, and rainwater management, selling primarily through perpetual licenses to engineering consultancies, municipalities, and municipal utilities across the DACH region.

Ownership category

akta.pro rank

Product category

Hydrology and Urban Drainage Software

NAICS

Computer Systems Design and Related Services (5415), Custom Computer Programming Services (541511)

SIC

Services-Prepackaged Software (7372), Services-Computer Integrated Systems Design (7373)

akta.pro primary industry

Sewer Network Modeling, Capacity Planning & Optimization (EUANACAK)

akta.pro secondary industries

Flood Risk Modeling, Mapping & Forecasting (Hydrology/Hydraulics, Digital Twins) (EUANAEAH), Real-Time Monitoring & Smart Stormwater (Sensors, SCADA/IoT, RTC) (EUANAEAK)

Keywords

• Urban hydrology software
• Sewer network simulation
• Stormwater management tools
• Precipitation data analysis
• Drainage engineering software

Headquarters

HQ city

Delmenhorst

HQ country

Germany

HQ region

Europe

Offices1 record

Markets served

GTM type

B2B

Offering type

Software

Cost components

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

Revenue model

1. Software Licensing: One-time perpetual license sales for desktop software products including HYSTEM-EXTRAN, KOSIM, GIPS, FOG, NVIS, KOSTRA-DWD, and RW-Tools. Both single-seat and network licenses available with follow-up license discounts.
2. Engineering Consulting Services: Professional consulting and planning services in urban water management, including conceptual planning, optimization, radar data analysis, rainwater drainage, sewer networks, treatment optimization, water quality, flood protection, and integral cross-system approaches.
3. Training Courses: Software training courses and educational programs for urban hydrology topics, offered as live-online courses and in-person sessions.
4. Customer-Specific Software Solutions: Custom software development services creating bespoke solutions based on the company's proprietary technology platform.
5. Web Software & Data Services: Web-based data services including NVIS-Web portal for precipitation data, raingauge data, weather radar data, area precipitation, and synthetic precipitation time series.

Pricing tiers

Go-to-market motion1 record

Distribution channels1 record

Marketing channels4 records

Core offering

ITWH GmbH develops and sells specialized desktop software for urban hydrology, sewer network simulation, precipitation data analysis, and rainwater management, anchored by flagship products HYSTEM-EXTRAN (hydrodynamic sewer modeling), KOSIM (long-term rainwater simulation), GIPS (CAD-integrated drainage planning), FOG Pro (GIS-based sewer modeling in ArcGIS Pro), NVIS (radar rainfall visualization), and KOSTRA-DWD 2020 (heavy precipitation regionalization). The company complements this software portfolio with engineering consulting and planning services for urban water management, customer-specific software development, and live-online training courses.

Product overview

ITWH GmbH (Institut für technisch-wissenschaftliche Hydrologie) is a German software and engineering company specializing in urban hydrology, sewer network simulation, and rainwater management. Its product portfolio consists primarily of Windows desktop software for drainage engineering, organized into several core product lines: (1) HYSTEM-EXTRAN (hydrodynamic sewer network simulation, available as core product plus Langzeit and Verteiltes Rechnen add-ons); (2) KOSIM (continuous long-term simulation for rainwater treatment and retention); (3) GIPS/GIPS-Light (graphical drainage planning integrated with AutoCAD/BricsCAD); (4) FOG Pro (GIS-based sewer network modeling in ArcGIS Pro, with urban flash flood 2D analysis); (5) NVIS (radar rainfall data visualization and analysis in ArcGIS Desktop, with server, forecast, and visualization modules); (6) KOSTRA-DWD 2020 (precipitation data software for Germany); (7) PEN-LAWA 2010 (extreme precipitation extremes database); and (8) the RW-Tools.xlsx Excel-based planning tool family (base, A138, ULTRA, and DIN1986 variants). The company also offers web-based data services through the NVIS-Web portal for precipitation data, custom software development, engineering consulting, and professional training courses. Legacy/discontinued products include FOG (superseded by FOG Pro), ATV-A138.XLS, and GRUNDSTÜCK.XLS.

Differentiator

Problem solved

Functional benefit

Brands

• HYSTEM-EXTRAN: Hydrodynamic calculation software for extensive sewer networks
• FOG Pro
• GIPS
• KOSIM
• NVIS
• itwh KOSTRA-DWD 2020
• RW-Tools.xlsx
• NVIS-WebPortal

Products and services

• HYSTEM-EXTRAN Flagship hydrodynamic calculation software for extensive sewer networks, used for hydraulic capacity verification, rainwater treatment verification in combined systems, and water balance calculations for catchments. Combines HYSTEM surface runoff with EXTRAN pipe network simulation.
• KOSIM Continuous long-term simulation model for the design and analysis of rainwater treatment facilities, rainwater management, and retention structures. Available in English as KOSIM 7.
• GIPS / GIPS-Light Graphical information and planning system for urban and settlement drainage running as an add-on to AutoCAD (2020–2026) and BricsCAD Pro (V20–V25). Enables design, analysis, and maintenance of drainage networks on PC. GIPS-Light is a lower-cost reduced-functionality variant.
• FOG Pro GIS-based information and planning system for building and maintaining digital sewer network models in ArcGIS Pro (requires ArcGIS Pro 3.x). Creates 2D terrain models with or without sewer networks for urban flash flood analysis and supports coupling both models for heavy rain impact assessment.
• NVIS Tool for visualization and analysis of georeferenced radar rainfall data in a unified spatial reference with sewer network and catchment information. Modular: NVIS-Server (radar data correction), NVIS-Vorhersage (rain short-term forecasting/nowcast), and NVIS-Visualisierung (visualization/analysis). Uses DWD RADOLAN radar data.
• itwh KOSTRA-DWD 2020 Desktop software for coordinated heavy precipitation regionalization analyses (KOSTRA) by the German Weather Service. Provides precipitation depths and rates by return period (1–100 years) and duration (5 min to 7 days) for Germany, with EULER model rain generator, SRI calculator, and export to XML, PDF, and MD formats.
• PEN-LAWA 2010 LAWA-authorized digital database of practice-relevant precipitation extremes for Germany. Contains return periods up to T = 10,000 years and durations from 15 min to 72 hours, derived from the PEN project at Leibniz University Hannover.
• RW-Tools.xlsx family Family of Excel-based planning assistants for rainwater management, including RW-Tools-A138.xlsx (DWA-A 138 infiltration), RW-Tools-ULTRA.xlsx (extended methods beyond A 138), RW-Tools-DIN1986.xlsx (flooding verification per DWA-A 138-1 and DIN 1986-100, successor to GRUNDSTÜCK.XLS), and the base RW-Tools.xlsx.
• NVIS-Web Portal Web-based data portal for precipitation data in Germany. Users can view current precipitation conditions, download rain gauge data in MD and UVF formats, access radar-based precipitation summaries, areal precipitation calculations, and synthetic precipitation time series.
• Software Training Courses (Schulungen) Training courses covering itwh software products and related hydrology topics (urban hydrology, radar rainfall data, KOSTRA data, sewer network simulation), delivered as live-online courses since June 2025.
• Engineering Consulting and Planning Services Engineering consulting and planning services for urban water management, covering radar rainfall data analysis, surface rainwater drainage, sewer network hydraulics, treatment process optimization, water quality, flood protection, and integral cross-system approaches.
• Custom Software Development Services Bespoke development of customer-specific software solutions built on the company's proprietary hydrology technology platform.

Segments3 records

Ideal customer profiles3 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Integration12 records

Feature8 records

Partnerships

Four partnerships are on record, tiered core.

• Deutscher Wetterdienst (DWD)coreTechnology or IntegrationThe German Weather Service provides precipitation data including RADOLAN radar data and KOSTRA statistical precipitation data that ITWH software products process and make accessible for urban drainage planning applications.
• EsricoreTechnology or IntegrationITWH software products including NVIS, FOG, and FOG Pro are integrated with Esri ArcGIS Desktop and ArcGIS Pro platforms for GIS-based visualization and analysis of drainage networks and precipitation data.
• LAWA (Bund/Länder-Arbeitsgemeinschaft Wasser)coreStrategic or Co-development PartnerLAWA commissioned the PEN project for practical extreme precipitation values. ITWH developed PEN-LAWA 2010 as the authorized digital database based on project results from the Institute for Water Management at Leibniz University Hannover.
• AutodeskcoreTechnology or IntegrationGIPS software operates as an application integrated with Autodesk products for CAD-based drainage network design and planning.

Scale indicators2 records

Recent moves6 records

Expansion highlights5 records

Broad incumbents

• Bentley Systems: Global infrastructure engineering software incumbent offering OpenFlows SewerGEMS, CivilStorm, and PondPack — direct competitors to ITWH's sewer modeling and stormwater products, bundled within a much broader BIM and digital-twin portfolio (OpenRoads, iTwin) targeting the same municipal and engineering markets.
• Wallingford Software (now Jacobs, formerly HR Wallingford / InfoWorks): Originator of the InfoWorks suite (CS, ICM) for urban drainage and river modeling, now part of Jacobs. A direct legacy competitor to HYSTEM-EXTRAN and KOSIM in hydrodynamic sewer network simulation, with strong adoption among UK and Commonwealth water utilities and consulting engineers.
• Esri: GIS platform incumbent that hosts ITWH's NVIS and FOG Pro as ArcGIS add-ins and is therefore both a core integration partner and a potential competitor if Esri expands native hydrology modeling capabilities. Provides the spatial data backbone across most of ITWH's GIS-based products.
• Autodesk (InfoDrainage / InfoWorks ICM via Innovyze): Both an integration partner (AutoCAD hosts GIPS; ArcGIS hosts FOG/FOG Pro) and a direct competitor through InfoDrainage for site-scale stormwater design and InfoWorks ICM (acquired via Innovyze) for urban catchment modeling. As ITWH's largest platform dependency, Autodesk represents the most strategically consequential peer relationship.

Emerging players

• FLO-2D Software: Specialist provider of 2D flood and urban flash flood modeling software, directly comparable to ITWH's FOG Pro 2D surface flow and 'Urbane Sturzfluten' urban flash flood modules. Smaller and more focused than ITWH but competes in the same heavy-rain impact assessment use case.

Regional players

• BGS IT (HYDRA / Dyna)](https://www.bgs-it.de): German water management software provider with HYDRA and related wastewater/hydrology tools, primarily serving DACH municipalities and engineering consultancies. Direct regional competitor in the German wastewater and stormwater modeling space, with overlapping customer base to ITWH.
• KISTERS: German-headquartered software vendor offering water resources, hydrology, and environmental data management solutions across DACH and Europe. Competes with ITWH in adjacent water-management software segments and shares similar DACH-centric regulatory orientation, making it a natural regional peer.
• Aquasolve / Aqualog (WASY GmbH): German water management software provider under the WASY/Aqualog umbrella, focused on hydrology, sewer network, and groundwater modeling. Competes with ITWH for the same DACH municipal and engineering office customers, particularly in integrated water resources management projects.
• Hydrotec (FloodWorks / Niederschlag-Abfluss-Modelle): German specialist in hydrology and flood modeling software, offering products for rainfall-runoff simulation and flood forecasting that overlap with KOSIM, NVIS, and HYSTEM-EXTRAN. Closest German-headquartered peer in terms of regulatory alignment (DWA/DIN) and customer base.

Direct peers

• DHI Group: Danish engineering software provider behind MIKE URBAN and MIKE+, the most direct global competitor to ITWH's HYSTEM-EXTRAN in hydrodynamic sewer network modeling, urban drainage, and flood simulation. Targets the same engineering offices and municipal customers with a comparable modeling core but broader international footprint.

Market position

Strengths4 records

Weaknesses4 records

Competitive moat5 records

Key risks5 records

Key highlights6 records

Customer concentration

• YouTubeyoutube.com/c/ItwhDeutschland
• LinkedInlinkedin.com/company/itwh-gmbh-hannover

Revenue estimate

Valuation estimate

Number of profiles

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 itwh