10-21-2003 - wetland class., ident., delin., & staking serv.

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• Figure 6 illustrates the monthly precipitation for the 12-month period prior to the site visit (October 2002 — September 2003) compared to average monthly precipitation and the WETS 30% upper and lower limits. WETS is a method of determining the normal range for monthly precipitation required to assess the climatic characteristics for a geographic area over a representative time period. According to Figure 6 the St. Minneapolis/St. Paul International Airport weather station recorded 17% of the months (October 2002 and May 2003) above the WETS Upper 30%Limit, 42% exhibited average precipitation amounts (February through March, June and September) and 42% of the months (November and December 2002, January, July and August 2003) exhibited precipitation amounts below the WETS Lower 30%Limit. Figure 7 illustrates the precipitation deviations from a thirty-year average(1971 — 2001) of 29.41 inches per year. This graph illustrates that precipitation has been below average for two of the past ten years. SER personnel examined the subject property for areas meeting jurisdictional wetland criteria during the site visit and delineated one area as being jurisdictional wetland. Detailed vegetation, soils, and hydrology data for the wetland are provided in the data sheets of Appendix A. The photo log in Appendix B further illustrates the conditions present at the site during the time of the site visit. SER delineated basin 1 as a Palustrine (P-)type wetland exhibiting emergent wetland vegetation (-EM-)with a seasonally flooded (-C) moisture regime or a Type 3 (PEMCd)wetland. Upon initial inspection of basin 1 SER determined that wetland hydrology did not exist due to a 10-nch inside diameter drain tile that was installed by previous property owners(Figure 8). The drain tile itself was constructed of clay material, which would indicate it was installed possibly 80 to 90 years ago. The abnormally dry months of July and August may have further contributed to the lack of hydrology. SER personnel traced the drain tile in an east-west direction(Photos 1 and 2) along the northern edge of the basin on the subject property. A junction point was found that extends south through the center of the wetland and north under Woodhill Avenue onto the adjacent property(Photos 3 and 4). The drain tile was traced further on the adjoining property and was found to extend briefly north and continues northwest toward the Orono Public Golf Course where it empties into a drainage ditch(Photo 5). While having the wetland criteria of the soils and vegetation, it presently lacks hydrology due to the drain tile, which is currently functional. With hydrology lacking due to the presence of the large drain tile, one of the parameters is missing, thereby creating a non jurisdictional wetland. Local observations earlier this year indicated that the drain tile suddenly became operational, discharging a large volume of water downstream causing flooding of the Orono Public Golf Course. This sudden discharge was reported to the city of Orono and the Minnehaha Creek Watershed District who both sent field staff to observe the situation. Neither party stated that they had the authority to complete a repair. Therefore based on the wetlands current conditions as confirmed by the sudden downstream water surge earlier this year, it is SER's opinion and conclusion, given the lack of hydrology that the,wetland is effectively drained and is a non-jurisdictional wetland. The presence of hydric soil and hydrophytic vegetation would indicate that hydrology existed at one time in the recent past and that during a year with normal rainfall, hydrology would likely return if the drain tile system was removed or closed. , z