Cypress Creek Basin Clean Rivers Program Nutrient Special Study Update Report – May 16, 2007 Roy Darville

Study Objectives determine the quantities, seasonal patterns and source watersheds of nutrients (nitrogen and phosphorus) presently being supplied to plant and microbial populations in Caddo Lake over an annual cycle support the development of a nutrient budget to assess the trophic status (i.e., stage of reservoir eutrophication or nutrient enrichment) of Caddo Lake in comparison with similar systems within the Cypress Creek Basin and the surrounding area

Parameters Collected field: water temperature, dissolved oxygen, pH, specific conductivity flow: USGS & USACE internet data (except at James Bayou CR3312) nitrogen – nitrate nitrogen – nitrite total Kjeldahl nitrogen ammonia nitrogen phosphorus total organic carbon chloride

Study Sampling 6 sites 1) Willow Pass Spillway 2) James Bayou CR3312 3) Black Cypress SH49 4) Big Cypress SH43 5) Little Cypress US59 6) Big Cypress Below Lake O the Pines dam 19 sampling dates First sample July 13, 2006 Last sample May 6, 2007

Willow Pass spillway – Jan 28, ,300 cfs Caddo spillway – Jan 25, ,300 cfs

James Bayou CR3312 May 6, 2007 Little Cypress Bayou – US59 May 6, cfs

Black Cypress – SH49 May 6, cfs Big Cypress – SH43 May 6, cfs

Big Cypress – Below L.O.P. May 6, cfs Big Cypress – Below L.O.P. February 1, ,660 cfs

Sample dates