Ushahidi is a crowdsourcing software which can be installed and customized. It receives reports via direct submissions on the website, but also connects to mobile apps and SMS plataforms, such as Frontline.
Crowdmap (on its Classic version) acts with the same functionalities of Ushahidi but with its dashboard and database hosted in the cloud. Most recently, Ushahidi has launched a new version of Crowdmap which works more as social network.
The tool has being extensively used on situations of nature catastrophes and humanitarian crisis. But they are good examples of environmental maps done with it (see the reference link on the side).