As our research on available watershed literature continues, we thought a map would help to frame our discussions. Below is a Mermentau River Watershed map. The watershed’s boundary was developed from the USGS National Hydrography Dataset, and is a combination of the Upper and Lower Mermentau Watersheds (HUC-8s). The background is USGS topo map available online through a web server. Also included for reference are Parish boundaries and labels. Some things i found surprising:
1. All or parts of 9 parishes drain into the Mermentau River: Allen, Evangeline, St Landry, Calcasieu, Jeff Davis, Acadia, Lafayette, Cameron & Vermilion.
2. The watershed area is approximately 5,200 square miles or 3.3 million acres.
3. the northernmost watershed limit is less than 2 miles from Rapides Parish (which contains Alexandria, LA – commonly referred to as the capital of CENLA).
The National Resource Conservation Society (NRCS) publishes Rapid Watershed Assessments (RWA) for various watersheds across the country to “increase the speed and efficiency generating information to guide conservation implementation, as well as the speed and efficiency of putting it into the hands of local decision makers.” Luckily, the Lower Mermentau Watershed (LMW) is one of the few Louisiana watersheds which has been published (study available here). The LMW is the portion of the river below the confluence of Bayous Nezpique and Plaquemine Brule; this confluence is just north of the Village of Mermentau, LA.
I have read through the RWA for LMW and describe it as a general discussion on the natural resources (soil, water, air, plants & humans), threats to these natural resources, and an assessment matrix of future conditions. While i will stop short of recommending that you all read the report, i do recommend scrolling down to page 37 which is where the RWA Meeting summaries begin. These meetings were held in 2007 in Abbeville and Jennings to solicit public comment and concerns. Many of the same themes are heard there as were discussed on 2/19. 12 years apart, and the talking points are the same. What is different now? The Louisiana Watershed Initiative (LWI) will, if the available published data can be believed, incentivize analysis of full watersheds. Lets keep this going. Flooding in the lower portion of the watershed dominated our 2/19 discussion, and will likely continue to be the major initial focus. What else do we want to consider? What are the upland areas’s concerns?
I will continue to research available literature on the MRW, as time allows. I am reviewing documents of the project described by Phillip “Scooter” Trosclair at the 2/19 meeting. As you recall that project proposes to increase connectivity across LA 82 which cuts across the Lower Mermentau Basin. If you have any questions, comments, or information to provide, please do. More later.