03/27/2013 ZONING BOARD OF APPEALS Minutes

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Jon Furbush asked; "if he was referring to the plot plan showing 48" inches of • concrete retaining wall in the back of the property?" John Slavinsky said; "yes, the bottom of the footing is elevation 3 and it sets about a half foot above ground water. The existing grade on the abutting property is elevation 7 and the top of the wall will be elevation 9.3." John Slavinsky stated the Board asked for the drainage specifications (Hydrocad Report, Residential Area Runoff Volume= 1,592CF). The report illustrates what currently exists regarding water flow onto the property between the abutting lots and the issue with water flowing onto Squaws Lane. This event is about 5.5 inches of substantial rainfall within 24 hours over a 25 year event. The 1,850 cubic feet is about 14,000 gallons of water. From a drainage view, this amount is not a lot of water and is about the same amount of water as a 24 foot above ground pool. The second report, (Hydrocad Report, Residential Area Roof Runoff only) is drainage coming off the roof of the proposed house and shows the intercepted trenches at the drip edges and how it collects water. The trenches are 2 feet deep and within a 24 hour time span, with 5.5 inches of rainfall, and approximately 18 inches of water is collected in those trenches. This is still an excessive 6 inches of water, which answers the question of the "sponge" affect. As the study depicts, the curves show the real saturation point within a 12 hour period. If you dug down • about 18" inches you would still have water, and below that would dissipate. The third report (Hydrocad Report, Residential Area, Lawn & Gravel, Drive/Parking) illustrates the calculation of 5.5 inches of rain water that is flowing toward Squaws Lane. The question asked; "will this intercepted 2 foot, wide, 4 foot deep trench handle the water?" There will be approximately 4 inches of water in the trench at the end of a storm. There's about 12 tons of trench more than necessary which is acceptable because it's a leaching trench.. Leaching trenches start to decay at the first drop of water and have an approximate life expectancy of 15 years. This project will be 14,000 times better than what exists now over a 25 year event. In a 50 year event, there will probably be about 2 feet of water on Squaws Lane, in 100 year event there will be about 5 feet of water on Squaws Lane. The trench is made with a layer of textile fabric on the sides and top. There will be no trees or shrubs surrounding these trenches. Jim Reiffarth asked; "if the covered porch on the plot plan is considered part of the lot coverage?" John Slavinsky said; "Yes it is. The existing lot coverage is 20.2 feet and proposed is 20 feet." 0