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Page 2 of 2 <br /> <br />Additionally in the most recent NPDES – MS4 permit renewal the City is obligated to develop a <br />pond maintenance strategy over a 6 year period. The steps of this assessment process and the <br />schedule to complete these steps are listed below in Table 1. This table is taken from the City of <br />Arden Hills NPDES permit. <br /> <br />Table 1 - Pond Assessment Procedure and Schedule <br /> <br />Activity Timeline <br />Determine and delineate the subwatersheds that drain to each <br />City owned pond. <br />Year 1 (2015) <br />Determine the percent of land use cover and soils within <br />each subwatershed to achieve a runoff curve number. <br />Year 2 (2016) <br />Determine the time-of-concentration for each subwatershed. Year 3 (2017) <br />Determine original pond wet volumes from construction <br />plans and as-builts. <br />Year 4 (2018) <br />For ponds with no size information: Using waders or a small <br />boat, gather water depth and sediment depth information for <br />each pond. <br />Year 5 (2019) <br />Pond effectiveness calculations: Using the data gathered <br />from the previous years, input this information into the <br />model chosen for determining the effectiveness of each <br />pond. <br />Year 6 (2020) <br /> <br /> <br />The Pond Assessment Procedure is intended to create a framework by which the city can make <br />decisions and plan for maintenance of its stormwater treatment facilities. At the completion of <br />the process, it is anticipated that, the City will be required to report on progress in applying the <br />pond maintenance schedule. <br /> <br /> <br />Attachments <br /> <br />Attachment A: Elfering & Associates Proposal <br /> <br /> <br /> <br /> <br />