Soil drainage calculator. html>po
But when grading around a house, all you need are stakes and string. Prior to release, all revisions will b e coordinated with the Forms and Procedures Office to Feb 18, 2022 · Drain Pipe Slope. Before placing your raised garden beds in their permanent location, be sure to remove any grass or perennial weeds from the area. Thanks. Next, input the depth of the excavation as 15 cm. 9mm to 600mm. Conductance – 1/ohm. how deep you want the soil (“desired depth”) The width of the garden bed is 7 feet 2 inches. , raised bed soil containers. It has been used in these applications for hundreds of years and is for nonpressure applications where temperatures will not exceed 212 F. See the references at the bottom of the page for more complete tables including impact of slope. 30 / 24. Step 4. Diagram 1. Building a soakaway in clay soil can be challenging due to the low water infiltration rates achieved in most clayey soils. The relative proportions determine the textural class. 3- Draw a polygon inside the shaded color of a soil type. Dec 12, 2023 · EPA’s National Stormwater Calculator (SWC) is a software application tool that estimates the annual amount of rainwater and frequency of runoff from a specific site using green infrastructure as low impact development controls. Establish the depth – thickness of the topsoil layer. 33 m2 trench bottom area needed. 5 = 28 yd³. You can use the calculator in reverse, too! Improved surface and subsurface drainage is necessary for some Minnesota soils to optimize the crop environment and reduce production risks. So, you’d need two 25-litre bags. e. 1. 0125 = 80. Feb 10, 2018 · For example is a 24 metre section of drainage pipe has a fall of 0. The SWC is designed for use by anyone interested in reducing runoff from a property, including site developers Therefore, the calculator uses only four categories of slope – flat (2%), moderately flat (5%), moderately steep (10%) and steep (above 15%). Truck Crops . The coarsest soils (sandy soils) are on the left and the finest soils (clay loam) are on the right. Calculate Clay Percentage: The percentage of clay is automatically calculated as the remaining percentage to reach 100% after sand and silt percentages are inputted. 33 ÷ 0. For this example, let’s consider a 20 ft. You first have to enter the volume or weight of the available river rock you have, whichever value is known for this requirement. With a pocket-sized agricultural drainage calculator, you can: Compute the required pipe size for a given drainage area. Shop Soil. About the calculator. Geotechnical engineering calculation applications for settlement, bearing capacity of shallow and deep foundations, liquefaction, SPT corrections and more for free. For desired soil depth, we want 8 inches. Welcome to the Michigan State University - US Forest Service Soil Drainage Index and Fertility Index web page. Flow Capacity (GPM at 1%): 0. The tables provide estimates of the curve number (CN) as a function of hydrologic soil group (HSG), cover type, treatment, hydrologic condition, antecedent runoff condition (ARC), and impervious area in the catchment. Finally, pick a soil type. Jul 13, 2024 · The backfill primarily aims to provide adequate drainage to your retaining wall. How to Use the Formula. 1 Mulch Bulk Soils Chemicals Clearance Concrete Delivery Options Drainage Edging Euro Quarries Fertilizer Agricultural drainage. Given bag size, it also calculates the number of bags of soil (dirt) you will need. 3/8 to 1/2. Where: Q = peak discharge, ft 3 /s (m 3 /s) C = runoff coefficient = percentage of rain that appears as direct runoff. If a 48 metre section of drainage pipe has a fall of 0. 05 cubic metres, that’s 50 litres. 6 3. Quantity. round. 900. Let’s solve an example; Find the drainage Use this soil calculator to easily estimate how much soil (topsoil) in tons or tonnes, or volume (cu ft, cubic yards or cubic meters) you need for a given gardening project. By calculating the soil infiltration rate, users can make informed decisions related to land management, agriculture, hydrology, and environmental conservation. If you are planning to create a trench for water drainage, plumbing/sewer/heating installation or other purposes, we recommend using this calculator. Soil Type. Example - 2: Drainage Pipe (Waste) Pipe Sizing. 172 gallons/m³ = 498 gallons). The triaxial shear test is the most versatile of all of the methods for testing the shear strength of soil and finding its cohesion (c) and angle of internal friction (φ). The usual minimum slope for drainage piping is as follows: For Pipe Size 2. 4- Click on "calculate" to run the tool. Gallons of storage provided: 0 gallons. 1/2 to 3/4 Calculate c av - φ av for layered soils to use in bearing capacity calculations for shallow foundations. 1- Zoom in to the area of interst. 5- Find the depth Step Two: Calculate the Rows and Columns. A Fixture Unit is not a flow rate unit but a May 11, 2023 · Additional amendments include: Lime - raises soil pH, reducing acidity. Cubic feet or yards. Drainage slide rule; Prinsco drainage calculator; Water quality and environment. 2. Fortunately, NDS provides online drainage calculators on their website as well as a mobile app. org Then measure each section separately. Let's say it's d = 0. So even one WC DFU is 4, pipe will be 3 in and not 2 in. This method is most accurate for runoff estimates from small drainages with large amounts of impervious area. Oct 14, 2021 · Use a watering bucket or hose to fill the hole with water. Soil EC was commonly reported in mmho/cm. X, Y, and Z are the corresponding values of each soil component in the soil triangle. We are able to assist you in your design by performing preliminary calculations and supplying AutoCAD layouts free of charge. The length of the garden bed is 11 feet 4 inches ( or 136 inches ). DFU are used to calculate the drainage flow from fixtures and the required capacities of sewer service systems. Example - 3: Sizing of building drainage sewer (3D Isometric) Example - 4: Sizing Vertical Stacks. g. Daily Design Flow for a 3 bedroom home of 1,300L/day, HLR of 30 L/day/m2 for a Loamy Sand (high sand content with small % of clay) and 0. lawn in loam soil, with a low spot where the water collects. Example - 5: Vertical Offset. 3. Drainage slide rule. Many of the physical and chemical properties of the soil depend on how fine (clayey Jun 9, 2020 · The fourth column in Table 1 presents the formula used for the calculation of J the M. A gradient may be defined as fall divided by distance. See full list on transformingdrainage. Drain Pipe and Fittings. Compute the acres drained for a given pipe size or grade. 5 cups Gardener's Supply granular organic fertilizer. NEW! Pipe Value Tool. Features. 1/2 to 3/4 . 6 m wide trenches. 9. In varved or laminated soils where silty fine sands are separated by clayey silts or clay, gravity drainage may be effective even if the average material has as much as 50% smaller than 0. Official adoption of the proposed revisions is made by State Drainage Engineer with input from the District Drainage Engineers. 3 days ago · Take the area covered by your pond (area = π × (2 m)² / 4 = 3. Break your garden into sections to measure. 884 m³ × 264. A = Drainage area, acre. Formula. For refreshing gardens, usually, 3-6 inches (76-152 mm) of new soil is sufficient. Make sure that there is no bottom, or drill holes in the bottom of the bed. Gallons to be stored: 0 gallons. These calculations are for non-traffic applications only. Decide on the depth of the new soil that you want. 5 cubic feet of soilless potting mix. Then input your desired river rock depth. Nyloplast Grate Inlet Size & Type Calculator Based on Peak Flow of Site Design. Click on the “Calculate” button to obtain the infiltration rate. Fill the hole with water. This tool helps you find the volume of the trench (cubic meter of soil) by length and width to estimate the cost of the corresponding excavation work. This may take several hours or overnight in clayey soils. These tables have become the standard for estimating lateral effect in Minnesota. 05 mm in diameter), silt (0. I = rainfall intensity, in/h (mm/h) Jan 17, 2024 · Soil Structure Formula: S = ( A ∗ X + B ∗ Y + C ∗ Z ) /100. 2- Turn on the "USA Soil Survey" layer in the bottom-left corner of the tool. Excavation calculator will help you to calculate exactly how much amount of land/earth needs to be excavated for house or building construction. Examples for Sizing Drainage Piping. Vermiculite - improves moisture retention and aeration. Divide the wall’s width in inches by the block width and round up; this is the number of columns. 141 m² × 0. 1. 05 – 0. 60 metres, the gradient would be calculated as follows. Jul 13, 2024 · You can also type the area directly into our calculator if you choose a more sophisticated shape. 0 gallons per minute. 15 minutes is the minimum length of time to be Rainfall Runoff Rate On Minor Size Land Formulas and Calculator. In cohesive soils, for instance, additional considerations may be needed to prevent soil erosion and settling around drainage structures. Where: D b = Drainage Density L = Total Length of all Stream Channel A = Area of Basin. Instantly, the calculator tells you that you require 0. Jan 30, 2024 · Enter the path's length and width as 5 m and 1 m, respectively. Feb 9, 2022 · What is the recommended fall for a soil pipe? The maximum fall for a waste pipe is 1 in 40. After you’ve entered the dimensions of the pot in our example, the formula should look like this: 3. Data Source: Peak Runoff Rate: 0 Gallons per Minute (GPM) 0 Cubic Feet per Second (CFS) Peak Runoff Volume: 0 Gallons. Input Parameters: Begin by entering the percentages of sand and silt into the designated fields of the calculator. 30 metres, calculate the gradient. Geological Survey (USGS) web application that provides streamflow statistics, such as the 1-percent annual exceedance probability peak flow, the mean flow, and the 7-day, 10-year low flow, to Mar 31, 2024 · How to Use the Soil Triangle Calculator. If the calculator says you need 0. 002 mm). 4 contains has updated historical meteorological data (from 1970 - 2006 to 1990 - 2019), updated Bureau of Labor Statistics Cost Data (from 2018 to 2020), and the 5. Fully saturating the soil before testing will increase the accuracy of this test. org for the latest information from SDSU Extension. Multiply this by your pond's depth to obtain its volume (volume = 3. This will saturate the surrounding soil, so that the real test will show true water drainage from your garden soil. Convert this rate to minutes per inch (divide the minutes by inches- 120min/5 3 days ago · Using our tool as a river rock coverage calculator. 2020. The slope of a pipe affects the velocity of wastewater moving through it, thereby influencing the efficiency of sewage systems and stormwater management infrastructure. It is used in drainage design. Access the Tool. For help with this taxonomic system, please go to the Soakaway in Clay Soil. The formula to calculate soil infiltration rate is as follows: When calculation runoff rate for storage, we use a 1 year 60-minute event. A well known steady-state drainage equation is the Hooghoudt drain spacing The State Drainage Engineer will coordinate the proposed revisions with all the affected offices and with FHWA. Container. There are two basic methods for elevating your soil above the surrounding ground: Hilling. 0 Mar 2, 2024 · To use the soil infiltration rate calculator, follow these steps: Input the required parameters such as the initial and final water depths, time elapsed, and area of the soil sample. The link to the online drainage calculator is here. Unit system. Soil texture influences nearly every aspect of soil use and management. For potted plants, you’ll likely need less soil than for other projects. A combination of 60 % sand, 20 % silt and 20 % clay (i. The Prinsco Drainage Calculator estimates the capacity of tile drainage systems. Underground Drainage. 0125. Then select the land-cover type where the rain will fall. 0412261060001 cubic inches. A simplified table is shown below. The range includes Drain, Sewer and Surface Water pipework and fittings in diameters from 53. Soils are classified into four HSG's (A, B, C, and D) according to their minimum Dec 16, 2015 · Silt and clay plus water are the binding agents that hold soil together. S. Gradient = 0. 33 mm. You are able to calculate acres drained, using both single and dual wall tile, calculate pipe diameter needed to drain your desired acreage, the amount of pipe needed for a job and the cost you can Drainage Calculators Toggle navigation {{calculator. Soil texture refers to the proportions of sand (2. 0 Cubic Feet. Here's what each part means: S is the soil composition. 172 to get the volume in gallons (volume in gallons = 1. The calculator’s results should be considered as preliminary information and not as a definitive determination of soil suitability. The Aco Channels cost calculator has many different options: Excavation Type (by machine, by hand) Disposal of Soil (skips, grab lorry, rubble sacks) Bedding & Haunching (ready mix concrete, mix on site concrete) Aco Drainage Channels (galvanized, plastic, ductile iron) Channels Installation Cost (predefined cost or set your labour rates) CULTEC Drywell Calculator. Compute flow rates for pipe sizes or grades. A particular pipe size on a given grade will only carry a certain amount of water. Soakaway Crates. Soil Calculator Calculate the amount of soil needed for your raised garden bed, potting container, or garden container. 007). = Total cubic metres of soil: For square or rectangular pots, the formula is length × width × height, so you can use the raised bed calculator above. Compressible, fine-grained materials containing an effective grain size less than 0. To begin, decide how much rain will fall by using the slide bar on the upper right. BWSR in coordination with the St. Total length of trenches = 43. Note the time. Most infields consist of 50 to 75 % sand with the remaining 25 to 50 % equally split between a local soil source and calcined clay . It can measure the total, as well as the effective stress parameters, and can be conducted on any type of soil. A layer of gravel (usually more than 1 ft thick) allows the water to drain away from the wall. Step 3. 015 Stormwater Management Model (SWMM) engine (from 5. 0 – 0. 4. Enter the depth of the French drain. I understand this feels like a WHOLE lot of math to go through for every project you do. The steeper the grade of the installed pipe, the more water it will carry. A soil percolation test, also known as a perc test or a percolation test, is a method used to determine the rate at which water can infiltrate or drain through the soil. StreamStats—A quarter century of delivering web-based geospatial and hydrologic information to the public, and lessons learned. 0 Introduction. Nyloplast Grate Inlet Calculator. 60 / 48 - Gradient = 0. For example, if your wall is 3 feet high and 30 feet long using blocks that are 6 inches high and 10 Sizing a Septic Drain Field, Calculation Example. 5 * 7 + (7 * 7)) / 3. Gypsum - improves aeration of compacted soil, helping it drain more efficiently. If the water drains rapidly, within 10 minutes, the hole should be refilled up to a maximum of 10 times. The Rational method runoff coefficient (c) is a function of the soil type and drainage basin slope. Imperial (in, ft or yd, lbs and tons) Metric (cm or m, kg and tonnes) Width. In most installations, an 8-12″ wide trench will suffice. This page is designed to help you calculate the Drainage Index (DI) and Fertility Index of any soil in the world, as long as it is classified within the US system of Soil Taxonomy. APPENDIX F – RATIONAL METHOD. Estimate permissible flow velocities for any pipe size, based on grade. 2 days ago · The calculation of pipe slope is crucial in ensuring proper drainage and flow rates in plumbing, civil engineering, and environmental management projects. Sulfur - lowers soil pH, increasing acidity. Using this formula, our 14 x 9 x 8 inch pot equals 844 . Depth. 5 inches and smaller: The minimum Slope requirement is 0. Saturate the local soil by filling each hole with water to a depth of at least 300mm and allow this to seep away completely. Soil Pipes, Waste Pipes and Fittings. X 30 ft. Feb 23, 2022 · Just for reference, pi (π) equals 3. Parameters in Hooghoudt's drainage equation. One of the most commonly used procedures for calculating peak flows from small drainages less than 200 acres is the Rational Method. the garden bed length. ft. Brett Martin provide complete underground drainage systems. 01 mm can be drained by providing a vacuum seal at the ground General Drainage Coefficients (inches/24 hours)* Without surface inlets . 25 inches per foot . X 50 ft. Soil drainage may determine which types of plants grow best in an area. Note that our Rational equation calculator allows you to use a variety of units. The next morning, fill the hole with water. Pound in one stake next to the foundation and another at least 10 feet away. mho – now Siemens. If you have a hard border or a raised bed, measure the depth of the partition. GRADIENT = FALL / DISTANCE. Full drainage design suite (50% Discount) including 7 spreadsheets; The Manning Coefficient for Sheet Flow is used with the Kinematic Wave Equation and other methods of calculating the velocity of sheet flow along the ground, typically during design storm events. The required parameters for the drain spacing calculator, with typical 0 Inches per Hour. 141 m²). Perlite - improves aeration and drainage. Place a stake or stick into the soil at the bottom of the hole so that it stands up straight out of the hole. SWC Version 3. DFU (Drainage Fixture Unit Values) is defined by the the Uniform Plumbing Code (UPC) and can be used to determine required drainage capacities from fixtures and their service systems. It finds the volume according to the formulas below: rectangular - e. 2 m . If we needed to know how many cubic feet, we would Pollinator terrace The above calculator functions well as a potting soil calculator or as a soil calculator for pots, but it is straightforward to work out how much soil you’ll need manually if preferred. Gradient = 1 in 80. When the hole is empty, note the time and calculate the time needed to drain the hole. The calculator shows your excavation area is 5 m². area of roof draining to a 40 ft. Create reports to calculate and compare the total installed cost differences between ADS dual wall pipe products and the competition. , a sandy clay loam to sandy loam) is often used. Based on the International Plumbing Code, the drainage piping system should be laid with a uniform slope. Poor drainage (causing water-logged areas) can often be identified by examining the soil color. name}} Visit iGrow. On average this will allow for about 5″ of gravel above a 4″ drain pipe, and 3″ of top soil/grass above that. Let the water fully absorb into the soil. Simulation of water flow and solute transport in free-drainage lysimeters and field soils with Jan 10, 2024 · 650. Storage Volume (Gallons per 10-ft bundle): 0. Use a garden fork or shovel to loosen the native soil to a depth of 6-10″. Length of trench required: 0 ft. volume of a cylinder: volume = π × R² × depth , where R is a radius. The amount of drainage piping slope depends on the pipe diameter. The above formula may be rearranged for Fall if the gradient is known: The Drain Spacing Tool estimates the optimum drain spacing that maximizes annual return on investment in the drainage system. Enter both areas and select the surface types from the drop May 16, 2024 · Depth. Quarts. 0 –3. The depth may need to be increased if there are any Our Products. Rainwater Guttering Systems. It is typically conducted to assess the suitability of soil for various purposes, such as septic system installation, construction projects or stormwater management. The standard depth is about 12″. The most common means for determining runoff for minor hydraulic structures is the rational formula: Eq. Rectangular. Finally, multiply this volume by 264. Minnesota drainage law (Chapter 103E) Minnesota Public Drainage Manual; Drainage history: The Upper Midwest Jul 13, 2024 · In our potting soil calculator, you can select between three different shapes. 6 m = 1. As the simulation runs, follow where the water flows. If soil is in direct contact with the bricks, water can pool, and the materials can degrade quickly over time due to improper conditions. Feel free to use and share this content, but please do so under the conditions of our Creative Commons license and our Rules for Use. 26 tonnes. This User’s Guide contains information on the SWC web application. This can be converted into a gradient written as a ratio or 1: some number. So pipes with a gradient between 1 in 40 and 1 in 110 should have adequate flow to prevent blockages from occurring. MS-Excel spreadsheet that calculates out the number of chambers requred based on the impervious area and rainfall event which is input. This value can be determined from the Drain Spacing Tool, here. 5 cubic feet of compost (4. Sep 29, 2020 · To calculate drainage density, two essential parameters are needed and these parameters are Total length of all stream channel (L) and Area of basin (A). As with soil type and drainage rate, any available SSURGO slope data will be displayed on the map if the View Soil Survey checkbox is selected. Divide the wall’s height in inches by the block height and round up; this is the number of rows. Q = C · I · A. You could also enter 86 inches. Mineral. Some clay soils will achieve virtually zero infiltration and in these soils a soakaway will not be practical. The formula for calculating drainage density: D b = L / A. Circular Space Calculator. 5 yd. Step 5. Soil Texture Spacing (ft) Depth (ft) Clay Clay Loam Average Loam Fine Sandy Loam Sandy Loam Peat and Muck Irrigated Soils 30 –50 39 –69 59 –98 98 –120 98 –197 98 –295 148 - 590 3. volume of rectangular cuboid: volume = depth × length × width. Distance from soil surface to bottom of the drain. Cast iron is the premier piping material for sanitary and storm drain, waste, and vent applications. Professionals can use this volume and considerations for soil type and percolation rates to determine the appropriate soakwell size. In this case, the average precipitation would be 783. It is the most durable DWV piping system available and can be used in all types of construction. 75 m³ of gravel, which weighs 1. However, actual choices for spacing and drainage coefficient should be based on balancing the costs with the expected benefits. Planning a landscape project or garden makeover and not sure how much mulch or soil you need? Calculating how much mulch or soil you need is simple and easy … just multiply LENGTH (m) X WIDTH (m) X DEPTH (m) or you can use the handy mulch and soil calculator below. It will take about 5 gallons (20 L) of water to fill. Note: First Flush is defined as first 15 minutes of runoff. Organic. For cube-shaped pots, you’ll need to use the following equation to work out the internal volume of the pot: V = Length x Width x Height. Field Crops. 141592653. The more you raise the soil above the surrounding ground, the faster the soil will drain. This can be converted into a gradient written as a ratio. 5 20-quart bags) 1. Jul 18, 2022 · the garden bed width. Selecting "Re-development" on the "Project Cost" tab of the National Stormwater Calculator influences the site complexity, and shifts the costs towards a higher complexity cost estimation. For soils that compress under shear, A > 1/3, and for soils that dilate under shear, A < 1/3 Under the fully drained condition, the excess pore pressure is zero, and pore pressure in satu- Agriculture Drainage Resource App The ADS Agricultural Drainage Resource is a complete tool to help you determine all of your drain tile needs. Tie a tight string to the stakes at the same distance from the ground, set a line level on the string and note the bubble. Drainage conditions can be controlled, and pore water The Soil Infiltration Rate Calculator is significant because it helps determine how quickly water can penetrate the soil, influencing water availability, drainage, and soil moisture levels. The volume of soil required is equal to this value. A, B, and C are the percentages of each soil component (sand, silt, and clay). Drainage issues and answers ; Nitrates in Minnesota drainage water ; How to reduce nitrogen loads from drained Midwest cropland; Minnesota drainage policy. You are at the right place to find how much area or square footage a certain volume or weight of river rock can cover. StreamStats is a U. 5 * 4. Examples are housing developments, industrial areas Fill the hole with water several times to saturate the soil. Multiply the area and dirt layer thickness to obtain its volume: 56 * 0. 6 = 72. Many agricultural soils need good drainage to improve or sustain production or to manage water supplies (Haroun, 2004 ). Calculator. Next, enter the width of the French drain. Typical value are included for use with the CivilWeb Rainfall & Runoff Calculator A drainage equation is an equation describing the relation between depth and spacing of parallel subsurface drains, depth of the watertable, depth and hydraulic conductivity of the soils. Can the calculator account for multiple drainage points or interconnected systems? Advanced versions of Drainage Fall Calculators can handle complex A raised bed is one way to elevate soil and improve drainage. The minimum fall is 1 in 110 (apart from vertical pipes, but that’s a different story). Shop Gravel. You can calculate the length, breadth and depth of the site for excavation. Electrical resistance – ohm. Other clay soils will achieve a low infiltration rate which makes a rainwater soakaway in Apr 22, 2024 · Inflow Volume=C×i×A×D. Historical Background Nov 22, 2022 · There’s more than one way to measure grade. Apr 25, 2024 · Yes, soil type influences drainage performance. Fill the hole with water and let it drain over night. 05 mm. For an elastic material, A = 1/3. 141592653 * 8 * ( (4. Drain Depth / Spacing - Table Varies with soil permeability, crop and soil management practices, kind of crop, extent of surface drainage. Where: C is the runoff coefficient, i is the rainfall intensity (mm/hr), A is the contributing area (m²), D is the storm duration (hours). 884 m³). is an empirical coefficient related to the soil's corn- pressibility and degree of saturation. If the water continues to drain away rapidly, the ground is unsuitable. The Percolation Calculator does not replace the need for thorough on-site assessments and professional expertise in soil evaluation for septic systems and drainage projects. Learn More. For saturated soils, B = 1. Alterations of the water regime by human activities, either through drainage or irrigation, are not a consideration unless they have significantly changed the morphology of the soil. To assure an effective and profitable system, it's important to couple a good design process with the thorough evaluation of such on-site factors as soil type, topography, outlet placement and existing wetlands. Paul District Army Corps of Engineers (Corps) has developed specific guidance The drain spacing calculator gives the recommended drain spacing given the choice of drainage coefficient and the soil and system parameters. 002 mm), and clay (less than 0. Drainage Pipe Required (minimum diameter): The Drainage Calculator determines the percentage of water that runs off any given surface and applies this to your calculation. This tool does not identify whether the field requires subsurface drainage. Example -1 : Drainage Pipe (Soil) Pipe Sizing. 1 mmho/cm equals 1 mS/cm, but because SI discourages the use of submultiples in the denominator, this unit is changed to deciSiemen per meter (dS/m), which is numerically equivalent to mmho/cm or mS/cm. 5) + 4. Checks the capacity of drain tile on existing drainage systems; Sizes the piping needed on the acreage to Drainage Class (natural) refers to the frequency and duration of wet periods under conditions similar to those under which the soil formed. Gradient = 1 / 0. Sewer. For an area of interest specified by the user, the tool provides drain spacing recommendations based on local soil and weather conditions. This report is commonly known as TR-55. To calculate the average precipitation for these three years, you add up the rainfall values (800 + 650 + 900 = 2350) and divide it by the number of years (3). # EZ-Drain of bundles required: 0. 1300L/D/m2 ÷ 30L/D/m2 = 43. A series of setback tables have been developed and refined over time by NRCS to estimate the lateral effect of various drains in different soil types. Re-development combined with information on site suitability, topography, and soil drainage determines whether complex, typical, or simple cost curves apply. ja oh wa no po dm uk tq qi ig