Natural Perspectives: Getting to the bottom of drained wetland

A new freshwater wetland formed at Bolsa Chica, but someone drained it. That's right, someone drained a wetland at the Bolsa Chica Ecological Reserve. Vic cautioned me to handle this issue with a cool and level head, but it chapped my hide to think that someone would deliberately drain a freshwater wetland in an area as fragile and contentious as Bolsa Chica.

But instead of going ballistic, I took action. I reported the draining to the California Coastal Commission and the Department of Fish and Game. Then I began investigating to find out who did it.

First, let me give you some background. This wetland is at the east end of the new footbridge by Warner Avenue. The area has always ponded a bit after storms. But ever since the installation of the footbridge, it has held a lot of water and has held it for quite some time. In January and February of 2010, the area was continually ponded.

This fits the definition of a vernal pool, which is a type of ephemeral, seasonal freshwater wetland. I thought this was a pretty exciting development, the formation of a potential vernal pool at Bolsa Chica. It was probably an accident of soil compaction by heavy equipment during bridge construction, but the area already had quite a bit of sloping, bowl-shaped topography. The soil compaction now allows water to collect there and stay for weeks.

After the heavy rains of December, the area again had a lot of water in it. I heard one report that the water was mid-calf-deep. The pond measured about 120 feet from east to west by at least 60 feet north to south, maybe more. I only measured it after most of the water was drained out, basing my measurements on water-logged, matted vegetation. The hand-dug, meandering channel that drained the wetland to the saltwater slough below the mesa was 40 feet long and about a foot deep. This was a deliberate act.

It didn't take me long to learn that the channel was dug Jan. 2 during a Bolsa Chica Land Trust Steward work party. I sent an e-mail to Kim Kolpin, who leads the Stewards, but she didn't respond.

I talked to Carla Navarro, the DFG biologist in charge of the area, and she said she had not given permission to anyone to dig a channel. She reported the incident to her supervisor, Karen Miner, and to U.S. Fish and Wildlife.