CWMS National Implementation Program

The CWMS NIP is providing $750,000 for software development in FY26. HEC will also receive $77,500 from the CWMS NIP to support the HEC-FIA Flood Damages Reduced effort. The following table and text describes those activities funded by the CWMS NIP.

Planned Activities

• Description of the activity is included on the CWMS ERC pages for those activities where the cost is shared between the CWMS ERC and CWMS NIP programs. 

Participate in CWMS NIP Monthly Working Sessions

The MMC hosts monthly working sessions on Microsoft Teams, providing HEC-HMS, HEC-ResSim, HEC-RAS, and HEC-FIA modelers with access to expert support. HEC staff will continue to participate in these sessions, as they have been highly valuable to users. These meetings are an effective platform for delivering field support, answering questions, and demonstrating key software features.

CAVI

Implement Impact Response Tool

The team will develop a new standalone tool to replace the Impact Response report currently within HEC-FIA. This tool will offer faster access to impacts based on forecasted stages from HEC-ResSim and/or HEC-RAS, eliminating the need to run forecasts through HEC-FIA to view Impact Response data.

Develop Regulation Assistance Tools

The Regulation Assistance Tools (RATs) are designed to support Water Managers in the real-time regulation of their projects within HEC-RTS. Over the past year, discussions have focused on identifying which RATs are needed to improve the efficiency of water management decision-making in HEC-RTS. These conversations have led to several initiatives: extracting the Impact Response Tool from FIA and integrating it into HEC-RTS, developing an operation decision validation checker to ensure final overrides comply with approved Water Control Plans, creating lightweight calculators, and designing a real-time hydropower override tool.

The Hydropower Tool is being developed as either a plugin or a standalone module within the current HEC-RTS platform. Its primary purpose is to enable Water Managers to define, adjust, forecast, and report reservoir release schedules specifically for hydropower generation. The tool will convert user inputs and release requirements into time series data written directly into the central database, overriding the default forecast model releases. Preliminary design meetings have been held with district offices in the southeastern region, particularly those collaborating with the Southeastern Power Administration (SEPA), as part of the Field Helping the Field (FHtF) initiative. Further meetings are planned with offices in the southwestern and northwestern regions, working with the Southwestern Power Administration (SWPA) and Western Power Administration (WPA), respectively, to gather additional feedback. The aim is to develop a minimum viable product (MVP) prototype that addresses the needs of as many Water Management offices as possible, ultimately enhancing real-time hydropower regulation within HEC-RTS.

Develop Lightweight Calculators

The team will design and develop a set of simple, lightweight calculators to enable quick lookups that support reservoir regulation decision-making. These calculators may include functions such as reservoir capacity, gate opening to flow (and vice versa), hydropower parameters like head, power, and flow, as well as a basic stage-discharge lookup. They will be lightweight tools that do not rely on database connections or model data, instead using manually entered data from the user. A straightforward project configuration file will define the project-specific data required for calculations. Preliminary mockups of some calculators have been created using a Jython script, which can be easily adapted for direct integration into HEC-RTS.

Investigate Changes to Forecast Folder Structure

The current folder structure for a HEC-RTS watershed can become confusing when multiple watersheds and forecasts are stored within a single directory. Currently, forecasts for all watersheds in a directory are kept together in the same forecast folder. Users have provided feedback requesting that forecasts be organized by watershed. In response, the team will explore an alternative approach to forecast file management, where forecasts for each watershed are stored in separate folders.

Design Capability for Default Extract List per Forecast Run 

Currently, the HEC-RTS Extract Editor supports creating groups of extract lists organized by data source and type. However, water managers often work with multiple Forecast Runs, each requiring different data inputs. The team will design new extract list features and settings that enable users to assign specific extract groups to run by default for only the relevant forecast runs.

HEC-HMS

Improvements to Ensembles

Additional work to the plugin code that integrates HEC-HMS into HEC-RTS is necessary for the HEC-HMS ensemble forecast run to be selected within HEC-RTS. Once completed, then you will be able to select and link input to and output from an HEC-HMS ensemble forecast compute to other models in the program order. 

Improvements to Combined Parameter Editor Interface

The team will work on improving the Combined Parameter Editor based on user feedback.

Preserve Table Settings Between Sessions

Currently, table attributes reset each time the dialog is closed and reopened. Enhancing the editor to retain user-defined settings—such as column widths or sorting preferences—would allow users to tailor the interface to their workflow and avoid repeated setup.

Add Menu Bar with Column Visibility Controls

This work will introduce a menu bar with options to show or hide table columns will help users declutter the interface. This allows them to focus on relevant data and hide columns that are not useful for their specific tasks.

Improve Plot Functionality

Currently, when a user recomputes a model in HEC-HMS with a graph open, the plotted results update but the axis scaling remains fixed. This enhancement would give users the option to either auto-adjust the axis based on new results or retain the original axis values.

HEC-ResSim

Update Documentation

The team will update the HEC-ResSim documentation to include new features, recent updates, and any known bugs that could not be resolved within the release timeline and budget. This documentation is crucial for modelers, providing them with the necessary information when upgrading to a new version of the software.

Develop New Tutorials

Tutorials will be developed to assist modelers in using newer HEC-ResSim features. Planned tutorials include the use of global variables and an application of the new water quality capabilities in HEC-ResSim 4.0.

HEC-FIA and Flood Damages Reduced

Testing HEC-FIA in HEC-RTS

The team will test HEC-FIA within HEC-RTS to ensure software compatibility. This early testing will help identify and resolve potential issues before the release of HEC-RTS 3.6, benefiting users in the field.

Fix Bugs and Release HEC-FIA 3.5

When bugs are reported—either by users or the development team—they are investigated to determine their root causes. The team then works to correct the underlying issues. Once fixes are implemented, the updated code undergoes rigorous testing to confirm that the problems have been fully resolved and that no new issues have been introduced. A new version of the software is released to users only after this testing is successfully completed. If major issues are discovered, a new version (HEC-FIA 3.5) will be released in FY26.

Develop New Tutorials for Flood Damages Reduced

In FY26, the team will add new tutorials to the Flood Damages Reduced documentation. These tutorials will offer districts additional examples of FDR methodology and HEC-RTS modeling techniques to support the computation of AFDR.

Field Support

The team will offer training and support to help field staff implement AFDR calculations using HEC-RTS.

Develop GIS Viewer for Flood Damages Reduced

The team, in partnership with the MMC, is working on a prototype that will showcase inundation data related to Annual Flood Damages Reduced. This tool will help the public better understand the impact and value of USACE reservoirs and levees. The viewer will compare flooding scenarios (both with- and without-project) for key events. It will either integrate with the existing MMC FIM viewer or be based on its framework, depending on which solution best supports the management and storage of FDR FIM data.