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HomeMy WebLinkAbout03.22.06 Work Session Minutes COUNCIL/PLANNING COMMISSION WORKSHOP MINUTES MARCH 22, 2006 1. Call to Order Mayor Soderberg called the meeting to order at 5:00 p.m. Present: Soderberg, Fogarty (arrived 5:10 p.m.), McKnight, Pritzlaff, Wilson (arrived 5:25 p.m.) Rotty, Barker, Fitzloff, Larson Also Present: Robin Roland, Acting City Administrator; Kevin Carroll, Community Development Director; Lee Mann, City Engineer/Public Works Director; Earth Evans, Engineer; Mark Rolfs, Engineer; Erik Peters, Engineer; Cynthia Muller, Executive Assistant 2. Approve Agenda MOTION by McKnight, second by Pritzlaffto approve the agenda. APIF, MOTION CARRIED. 3. Introduction 4. Sewer System Discussion The area between the eastern edge of Farmington and Biscayne Avenue and south of 220th Street to 230th Street to Pilot Knob Road was studied. The first issue concerns the existing capacity. There was enough capacity for 210 acres worth of development in addition to a school in the southeast area. This was referred to as the downtown line. It was determined there is .182 million gallons per day of capacity which is 182,000 gallons which equals 675 single family units or a combination of 50% single family at 3 units/acre and medium density at 7 units/acre that combination would be 775 units. Assuming a 30-acre elementary school on the Angus property the units would be reduced by 20-30 units. If it is a high school it would be reduced by 90-110 units. Regarding the Biscayne line, there is a wetland area for the Dakota County Agricultural Society. It is the intent that this area will always remain a conservation area, so that property was not included in the study for sewer service. Also, the engineers assumed the Fairgrounds would not be an issue until the interceptor comes through from Elko, so that area was also not included in the study. The land use assumed is the 50% low density at 3 units/acre and 50% medium density at 7 units/acre which equals 5 units/acre. In the next two years all of these plans will be updated for the entire City. Whatever comes out of the comprehensive planning process will be used for updating the plans. The City has developed at a higher density than what the plan originally accounted for in 1996. The Biscayne line is a potential line, it does not currently exist. There are 950 developable acres in the area for the Biscayne line. There were two options reviewed. One includes a lift station at the north middle section of the Peterson property at the southeast comer ofthe former Rother property. There would be a gravity sewer to that lift station and it would get pumped up to the interceptor. This is less disruptive along Biscayne Avenue to areas where they need to get easements. A force main has to be CouncilJPlanning Commission Workshop March 22, 2006 Page 2 buried 8 ft. A gravity sewer at points would be 20-30 ft. deep. The estimated cost is $3 million for the lift station, the force main, and the pipes. The approximate trunk area charge would be $3200/acre. This does not include land acquisition and dewatering costs. The second option is a gravity line which would take the gravity all the way to the interceptor. The estimated cost is $2,350,000 with a trunk area charge of $2500/acre. This would need more dewatering and more easements. Trunk area charges for the rest of the City are approximately $2,000. Another area reviewed is the Eureka line located in the southwest comer of Denmark and 220th Street. The cost is estimated at $1,210,000 with a trunk area charge of$2300/acre. Councilmember Fogarty felt the Biscayne line could be redundant if the interceptor would come in four years. City Engineer Mann spoke with the Met Council of doing this prior to the interceptor coming through. The Met Council did not think this would be a problem. If development were to occur there may be a need for the City to install the line and front the cost. This is subject to the availability of the fund. Ultimately the developer would pay through trunk funds. Mayor Soderberg noted the properties currently in the City can be served by the current line. Anything beyond that would need the Biscayne line. City Engineer Mann stated we have the capacity for half ofthe land available. Councilmember Fogarty asked if the Devney/Winkler property went into the downtown line and the Biscayne line was built out, would the cost be on the City to cover the portions ofthe Biscayne line that would run past the Devney/Winkler property. City Engineer Mann replied there are two options. One is the areas are all outside the sewer boundary and are in the study. Whether you connect into the Biscayne line or not, the trunk fee is x amount. The second option is if we want to finalize the plan, through the comp plan process, staff could look at exactly who will connect where and do a more detailed analysis as to the trunk fees. 5. Water System Discussion The area to the southeast is new to the study. The modeling assumes the existing densities from 1996. However, densities have been different than what the plan anticipated in 1996. This will be updated with the comp plan update. The ultimate maximum demand in the plan is 23.3 million gallons/day. This is when the City is completely built out. The land use density assumed is 5 units/acre for the new area which is higher than normal. This results in a maximum day demand of 2.86 million gallons/day. The Empire area which was eliminated would have been a maximum day demand of 1.38 million gallons/day. The net increase is 1.48 million gallons/day. This means the City would need one more well than anticipated and another 500,000 gallons of water tower storage. There are a couple areas were some water mains would need to be up sized. Wells cost $800,000. A 500,000 gallon water tank would cost less than $1 million if it can be added to another tank. If it has to be built on its own it would be over $1 million. The City currently has 6 operating wells and the 7th is being built. The City has the capacity to serve the areas currently within the City. Building a tower in the southeast area is not a viable option. It would be more likely to add storage to an existing tower. The net area studied was 800 developable acres. Council/Planning Commission Workshop March 22, 2006 Page 3 6. Surface Water Discussion With surface water, the City is not restricted from a capacity standpoint. It is estimated as to how much water will be generated in addition to or different than the existing condition, identifying what size facilities need to be constructed to handle the water from a rate control and a water quality standpoint. Being near the Vermillion River brings up issues such as temperature control and volume control. The study area includes the area east ofBiscayne Avenue because the storm water that flows from the west side of Biscayne will flow easterly. Staff also wanted to review the wetlands east ofBiscayne as part of the analysis. Depending on what the wetland is classified can dictate what type of storm water improvements or criteria the City will be held to to drain towards the wetlands. The major issue is the trout stream. The area is very flat with a high ground water table. The top soil is over sand. The Watershed is in the process of adopting standards for treating water before it can go to the Vermillion River. The main issues with the trout stream are water quality, temperature, and volume. The rate control has to do with flooding and how many cubic feet of water per second are flowing down a particular channel, pipe, or river at a particular time. Volume is a total amount of water. Anytime an area is developed, there will be more runoff, more volume of water. The rate can be brought down to existing levels or below. The surface water plan as the City is built out anticipates and plans for a lower discharge as far as rate is concerned to the receiving waters than what exists now. The volume would still be higher, but would be released at a much lower rate over a much longer period of time. Volume has been determined to be an issue with stream stability. How to handle storm water would be to have larger ponds that may be dug below the ground water. Part of this would be the developments in the area would need fill. The ponds would work by there being a difference in elevation between the water that would normally be in there (the ground water level) and the outlet. The water would rise to a certain level and then go through the outlet. The Prairie Waterway lowered the ground water table in the area. The agencies have expressed concern about doing that further because of the proximity to the Vermillion River. The outlet to these ponds would be above the ground water table. These types of ponds are the best way to remove pollutants, however they adversely affect the temperature. So the City is looking at ponds that will allow infiltration. Infiltration ponds have to have the water quality ponds in front of them as far as the way the flow goes. Staffwill not be proposing the Prairie Waterway type system. The rate will be lower than what it is today. So once the areas are developed there will be less cubic feet per second going through the drainage ways. The volume would have to correspond to what the Watershed requires in their standards. Currently the plan meets the Watershed's criteria. Staff needs to get a better handle on the Watershed's standards prior to determining the costs. So far the engineer has estimated $10,800,000 for the regional ponds and piping. This does include land costs. The water and the sewer will drive whether or not the east area is developed. If the area is developed, the storm water systems can be put in place. Staffwill need direction how or if the plans are finalized before the comp plan update. One option would be to finalize the plans or they could be a working document. The sewer is the bottom line as far as development in this area. Staff will need to meet with the Met Council soon. Mayor Soderberg noted we have properties on the east side that have expressed an interest in developing. Based on this information we can serve those with what we have. We need to determine if we want to do that and how we want it to look. Another joint CouncilJPlanning Commission Workshop March 22, 2006 Page 4 Council/Planning Commission Workshop should be scheduled. Council should advise staff of dates they would be available. It was suggested to hold the workshop in mid-late May. Council should advise staff as to what they want at that meeting and what they hope to achieve. 7. Adjourn MOTION by Fogarty, second by McKnight to adjourn at 6:57 p.m. APIF, MOTION CARRIED. Respectfully submitted, ~~ ;rv;~ Cynthia Muller Executive Assistant