Chemical Monitoring
Data Creek
| Monitoring Location | at Typo Creek Drive, Linwood Township STORET SiteID = DataCreek_TypoCreekDr |
| Monitored By | ACD Staff |
| Years Monitored | 2001, 2002, 2003 and 2006 |
| Background: This stream/ditch is the largest inlet to Typo Lake. Typo Lake is severely impaired by excess phosphorus and has intense continuous algae blooms. Data Creek has been monitored in 2001, 2002, and 2003 as part of a TMDL impaired waters study for Martin and Typo Lakes, and was found to be responsible for 62% of phosphorus loading to Typo Lake. These studies found an important source of phosphorus in Data Creek is periodic drying and rewetting of the ditched wetland soils through with the Ditch 20 tributary flows. In other words, circumstances created by ditching allow the release of phosphorus from the wetland peat soils by biological and chemical means. Any improvements to Typo Lake will be heavily reliant upon improvements to Data Creek water quality. Data Creek’s watershed of 7,674 acres is 40% agricultural, 26% wetland, and 2% residential, with the remainder being forests, grassland, and shrubland. Just upstream from the monitoring site the ditch flows through extensive wetlands. This stream carries a moderate volume of water, with typical flows ranging from 2-12 cfs |
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| Results and Discussion Eight water quality samples were taken in 2006, including four during storms events and four during baseflow (see figures and tables below). Overall, water quality was slightly worse than average when compared to other streams in the area. When compared to previous Data Creek monitoring it was far better than 2001 or the two samples taken in 2002, but slightly worse than 2003. Turbidity and phosphorus have been the most notable problems. While conditions were relatively good in 2006, May 30th stood out as an exception. Total phosphorus was two times higher than any other 2006 measurement and the third highest among 27 measurements since 2001 (431 ug/L). The water appeared brownish green, and had the highest turbidity (44 FRNU) and total suspended solids (50 mg/L) ever recorded for this stream. Dissolved oxygen was the second lowest ever recorded at this site (4.76 mg/L / 54%), and low enough to stress some aquatic life. The cause of such poor water quality on May 30th is unknown, but it was almost certainly climate-driven. Similarly poor conditions were also observed in the nearby Sunrise River and Cedar Creek on May 30. This was not associated with storms. Rather, water levels were dropping from springtime highs. Perhaps the organic peat soils through which the stream flows were sloughing into the stream as a result of drying. This organic soil could contribute nutrients and turbidity. It could also accelerate decomposition processes, consuming dissolved oxygen. The Ditch 20 tributary of Data Creek, in particular, flows through peat soils. This mechanistic theory is an interesting addition to our understanding of phosphorus loading to Data Creek (and by extension, Typo and Martin Lakes). Previously, data strongly suggested that the primary mechanism of phosphorus loading to Data Creek was that rewetting of dried wetland soils adjacent to the Ditch 20 tributary of Data Creek. 2006 was a moderate drought year with no significant rewetting periods that would have allowed observation of this phenomena. The relatively low phosphorus in the continuously dry years of 2003 and 2006 supports the theory that rewetting does drive the largest, longest lasting phosphorus releases. But the 2006 data suggest another phenomena can cause high phosphorus too. Phosphorus release observed on May 30th, 2006 and theorized to be due to drying of the soils, was just as large as those observed under rewetting conditions but of shorter duration. It also occurred only once, suggesting it happens only during specific circumstances. Add to this the textbook knowledge that a third set of conditions can also result in phosphorus release from these soil types – continuously wet conditions. These three phosphorus release mechanisms, all of which may operate in the wetland soils around Ditch 20 and Data Creek at different times, could make achieving low phosphorus in Data Creek through management actions difficult, though it may be possible to reduce the largest, longest lasting source – rewetting of dried soils. Even if all phosphorus releases due to rewetting of dried peats were virtually eliminated, Typo and Martin Lakes would not likely show improvement. 2003 and 2006 provided a test of this. Both were dry years when rewetting was minimal and Data Creek phosphorus was relatively low. Even in those years Typo Lake had very poor water quality (lake was monitored in 2003, visually inspected in 2006). This indicates that the lake itself is such a strong phosphorus source that the lake’s condition does not improve when the inlet water is improved. Improving Data Creek alone will not improve Typo Lake – internal loading sources must also be addressed. |
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