Monitoring equipment

Over the years, we've used a few different methods to monitor wetland hydrology. We started off with transects of Maxim iButton data loggers at depth intervals in ponds. The iButtons we use track temperature. Submerged iButtons record a different diurnal temperature signature than those out of the water. By comparing iButton temperature signatures along a transect we could determine the water level. iButtons are relatively inexpensive, tiny, and we ended up using them for side-projects as well. However……

Last season we switched to Onset Hobo U20L-04 water level data loggers. These Onset Hobo depth loggers are what we're crowdfunding to purchase more of. They provide greater resolution depth data, allow a longer deployment period, and simplify deployment. Initially we had avoided using depth logging (pressure logging) devices because they were relatively large and very visible. Last year the company Onset released a less visible black plastic depth loggers that we've been using. Many of the wetland sites we monitor are in National Parks and frequently visited by the public. Stealthy installation of our monitoring equipment is important as park visitors love to remove science equipment. Here's a photo of one of our new Onset Hobo depth loggers deployed in the backfountry, measuring the tiny amount of water left in a wetland: