Publishing open source
While everyone might not have a need for your specific open source tool, publishing it online can help others in unexpected ways. Other government agencies often share similar roles or needs and open source tools help lower the barrier of entry and resource cost to implementing a solution. The private sector has also been using more open source software than ever before. As we've seen the usage of open data, the public will often innovate on our work in ways that we can't anticipate. Releasing more tools as open source software increases the possibility of fueling further innovation.
Things to to look out for
Engagement: It's important to be clear about the level of engagement people can expect. Open source communities thrive on collaboration. Providing explicit information about how often people should expect updates to the code or responses to any issues raised goes a long way. It will help to consider increasing the level of engagement based on demand.
Sensitive Information: Sensitive information can sometimes make its way into commit messages or the code itself. Sensitive data, including personally identifiable information, should be maintained separately from where the source code is published. Before publishing, you should make certain that information like PII or passwords are not included in the publication. Tools like Clouseau can help you identify sensitive information in your source code.
Where to publish
There are a number of options for publishing your source code. Sites like SourceForge or GitHub offer an ability to collaborate with outside developers, but there are other options as well.