County Ditch Zion-Munson Scott Henderson Administrator Zach Gutknecht Ditch and Permit Coordinator
Tonight's Informational Meeting Drainage Authority s role Types of drainage projects Zion-Munson location The current benefits for Zion-Munson Determination of Benefits process Landowner comments
The Drainage Authority s Role is to assert the property owners drainage rights, since it is the only entity authorized to conduct work in the ditch McLeod County v. MnDNR The Drainage Authority effectively acts as the custodian and referee for the drainage system Protect the drainage right Keep system in state of repair Prevent unauthorized use and/or damage Balance interests Economic Environmental
Types of drainage projects New Drainage Systems Not very common, unless it is an addition to an existing system Repairs May consist of minor work such as spraying for weeds and brush, removal of isolated silt deposits, bridge or culvert cleaning, removal of vegetation, debris and other obstructions OR May also involve more extensive cleaning of the ditch bottom of silt deposits to the grade line and bottom width as originally constructed or subsequently improved Repairs over $100,000.00 will require a petition form benefited landowners Improvements Are projects that involve enlarging, extending, straightening, or deepening of an established system. May also include extensions downstream to a more adequate outlet, and/or extensions upstream called laterals.
County Ditch Zion-Munson
Established Grade
Current- Original Benefit Amount
Current Benefits
Current Benefits
Current Benefits Vs. Potential Watershed
Re-determination of Benefits The Drainage code gives little detailed guidance on how to determine benefits 103E.315, Subd. 5 the viewers shall determine the amount of benefits to all property within the watershed, whether the property is benefitted immediately or the project can become an outlet, makes an outlet more accessible or otherwise directly benefits the property The viewing process is a detailed appraisal of each individual parcel using land sales data, broken down by various soil types and land conditions. One Disadvantage of this process is it does not consider the long-term benefit, but only considers the market value for a specific point in time.
Re-determination of Benefits There are two different types of benefits; Direct and Indirect Direct Benefits are properties that have an altered landuse due to the construction of the drainage system. There are two different approach's for determination of benefits Increase in potential for agricultural production (income method) increase increase in current market value Example: Poorly drained pasture has a market value of $700 per acre for pasturing or conservation/wildlife purposes. Well drained agricultural lands in full production tile have a market value of $3,000 per acre. Lateral drainage tile system construction is estimated at $800 per acre Market Value Improved Condition $3,000 Beginning Market Value $700 Benefit Without Improvement Cost $2,300 Private Improvement Cost $800 Net Benefit from Project $1,500
Re-determination of Benefits Indirect benefits Is where the drainage project provides an outlet and benefits the property drained. These benefits are looked at three different ways 1. Benefits for proposed drainage projects as outlet 2. Increased sedimentation 3. Accelerated drainage
Benefits for proposed drainage projects as outlet Total project length - 2 miles Length of proposed project used as outlet - 1 mile Total watershed 1000 acres Existing system watershed 250 acres Benefit determination: Ratio of existing system to proposed projects drainage area 25% Length of proposed project length used as outlet 50%.50 x.25 = 12.5% of the estimated proposed project cost The total figure may also be adjusted to reflect other consideration such as the existing systems design and its need for an outlet
Increased sedimentation Is best described as upland areas contribute to the maintenance requirement and it only seems fair that they pay to remove the sediment which they contribute. Example: 5 Tons/acre/year soil loss Soil weight = 125 pounds per cubic foot 5% of sediment retained in system 25 year project life 1. 5 tons/acre/year * 2000 lbs/ton = 10,000lbs/acre/year = 80 cubic feet/acre/year (10,000 125 = 80) 2. 80 cubic feet/acre/year * 5% = 4 cubic feet/acre/year of eroded soil retained in system 3. 4 cubic feet/acre/year * 25 years = 100 cubic feet 1. 100 cubic feet 27 cubic feet/cubic yard = 3.7 cubic yards 4. 3.7 cubic yards at an estimated removal cost $2.00/cubic yard = $7.40 per acre benefit
Accelerated Drainage Is a procedure that can consider additional drainage Where the original drainage system was designed to drain only a limited portion of the watershed (e.g. wetlands) Additional property can be assessed if increased drainage results in increased system maintenance or drainage system capacity, because the natural drainage pattern has been altered or modified to accelerate the drainage of water.
Accelerated Drainage Example Watershed size = 1000acres Wetlands = 30 acres Native prairie = 70 acres Design rainfall = 3 inches Ditch length = 1 mile Without accelerated drainage = 163 cubic feet per second (cfs) With accelerated drainage = 260 cfs 1. Design ditch for without accelerated drainage condition: 1. 163 cfs, 4 bottom, 2:1 sideslopes, 5.2 depth required 2. 14,670 cubic yards @ $.70/cubic yard = $10,269 cost of excavation 2. Design ditch with accelerated drainage 1. 260 cfs, 4 bottom, 2:1 sideslopes, 6.2 depth required 2. 20,730 cubic yards @ $.70/cubic yard = $14,511 cost of excavation 3. Determine added ditch cost for acceleration drainage 1. $14,511 $10,269 = $4,242 4. Determine cost per acre for the 900 acres in watershed that have been altered: 1. $4,242 900 = $4.75/acre
Finished Example
Finished Example
Moving Forward Re-determination? Estimate $52,000 This estimate is based on a watershed size of 13,000 acres at $4.00 per acre Complete review of drainage efficiency Including surveying Grade re-establishment