Emoji Sediment in ICM InfoWorks Network

 🌊 Sediment in Water Systems 🌊

This section is incredibly crucial when diving into Water Quality Simulations 🌧️🔬.

🚰 Sediment in conduits 🚰 In InfoWorks ICM, sediment layers in pipes have a story to tell 📖. They're treated differently by the hydraulic model 🌪️ and the water quality model 🌈. Picture this: InfoWorks ICM is like a theatre 🎭, and it showcases two different layers of sediment in pipes, each playing its unique role.

🛌 The Two Sediment Stars 🌟:

1. Passive Layer 🛏️ - This is the chilled-out layer. Think of it as the sediment that's lounging around, fixed and unchanged during any dramatic rain event. It's just there, minding its business.
2. Active Layer 🏃‍♂️ - This layer is the real action hero. During a water quality simulation, it can be eroded, transported, and deposited. It's the dynamic part of the sediment story.

📏 If you add the passive and active layers, and they make up more than 80% of the conduit's height, well, no more dramatic scenes for the active layer. It's a wrap; no more deposition.

💡 You're handed the director's chair 🎬. You decide whether the drama in the active layer during a water quality simulation affects the overall hydraulic story or not. This directorial choice is yours in the QM Parameters Dialog.

🚫 If you choose to ignore the active layer's dramatics for the hydraulic story, it might be a good idea to cap the sediment depth a bit, maybe at 10%, just so the hydraulic and water quality stories aren't worlds apart.

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🌊🚰 Pipe Sediment in InfoWorks ICM 🚰🌊

🛌 Passive Layer 🛌: When sediment decides to take a break and just chill, you get the passive layer. It's fixed and doesn't change during any performance, acting mainly as a constriction on the stage (or pipe). How deep is this layer? Well, you set it using the Sediment Depth field for each conduit. Or, get fancy and define a unique set of Pipe Sediment Data for your show.

🏃‍♂️ Active Layer 🏃‍♂️: Here's where the action happens. This layer has one or two sediment stars 🌟, called Sediment Fraction 1 (SF1) and Sediment Fraction 2 (SF2). Each star has its own characteristics, like particle size and density. And if you want some behind-the-scenes control, you can tweak these characteristics in the Surface Pollutant Editor.

The active layer's drama is limited by: 📏 Maximum sediment depth - depth of Passive Layer

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🏞️ River reach bed sediment 🏞️

Like a trilogy, the river section bed has three parts:

1. Active layer 🏃‍♂️: This is the top layer. It's dynamic and ever-changing. You set its thickness, and as sediment gets deposited, some of it goes to the layer below.
2. Deposited layer 🍂: Think of this as the middle child. It's made up of sediment that once was active but decided to settle down.
3. Parent layer 🌍: This is the base layer - the OG sediment. It's the river bed, and it only gets eroded if the deposited layer is all used up.

Remember, these layers tell the story of the river, its history, and its future. So, take the director's chair and make the tale epic 🎥🍿.

Unpacking the Two-Pass Solution in InfoSewer

 Unpacking the Two-Pass Solution in InfoSewer

InfoSewer's dual-pass methodology is a cornerstone for achieving a meticulous and comprehensive analysis of sewer system performance. The two distinct passes each offer a layer of insight into various facets of the system, particularly focusing on the depth-to-diameter ratio (d/D) and the Hydraulic Grade Line (HGL).

Phase 1: Laying the Groundwork with Manhole Loads and Link Flows

The first pass serves as the initial survey, setting the stage for the entire simulation. During this phase, InfoSewer calculates the loads for each manhole and estimates the flow dynamics in the links connecting them.

• Key Output: The primary yield from this stage is the initial d/D values, which are often used for preliminary mapping.
• Primary Focus: At this juncture, the main attention is given to calculating manhole loads and estimating link flows.
• Use-case: This is especially useful for generating an initial hydraulic snapshot of the sewer network, which can be invaluable for early-stage planning and decision-making.

Phase 2: Advancing the Analysis with Backwater, Surcharge, and Pressure

The second pass builds upon the foundational data gathered in the first. This phase engages in a more nuanced analysis by incorporating calculations for backwater effects, surcharge conditions, and intra-system pressure.

• Key Output: The adjusted d/D values and the HGL emerge as the critical outputs from this phase.
• Primary Focus: The emphasis here is on advanced hydraulic modeling, including backwater estimation, surcharge analysis, and pressure calculations.
• Use-case: The second pass is vital for risk assessments, emergency response planning, and other high-stakes decision-making processes.

Interplay Between the Two Phases

The two passes are not isolated events but rather interdependent processes that feed into each other. The second pass takes the first-pass data as a baseline but refines it to account for the more intricate hydraulic phenomena, often resulting in higher adjusted d/D values.

Why Adjusted d/D Matters

The adjusted d/D, born out of the second pass, usually exceeds the initial d/D computed during the first pass. This variation is not arbitrary but indicative of the complex hydraulic factors like backwater effects and surcharging that were considered in the second pass. As such, the adjusted d/D serves as a more reliable and nuanced metric for assessing system performance and associated risks.

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This expanded perspective offers a multi-dimensional view of the Two-Pass Solution in InfoSewer, shedding light on its nuances, capabilities, and the significance of each stage in contributing to a robust and reliable sewer system model.

SWMM 5.2.3 Inlet Workflow from the Help File

SWMM 5.2.3 Inlet Workflow from the Help File

The process of conducting an inlet analysis using the Storm Water Management Model (SWMM) is quite thorough and systematic. Here, we provide a detailed expansion of the general workflow you've presented, demonstrating how to apply it to a simple street and sewer drainage system:

1. Layout both the street and sewer networks: Begin by designing and sketching your street and sewer networks. This involves determining the locations of your roads, open channels, and sewer lines, as well as their interconnections. This layout forms the fundamental skeleton for your model. You can use GIS (Geographical Information System) data or manual drafting to aid in creating the layout.

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3. Assign subcatchment runoff and user-defined inflows to individual street nodes: Next, designate the runoff from surrounding land areas (subcatchments) and any user-defined inflows to the nodes within your street network. Runoff is the water flow that occurs when soil is infiltrated to full capacity and excess water from rain, meltwater, or other sources flows over the land. User-defined inflows could be point sources of water other than the subcatchment runoff. This assignment takes into account how rainfall will be distributed in the area and which roads it will likely flow down.

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5. Create a collection of Street cross-sections: Design a collection of street cross-sections. These cross-sections represent a vertical slice through the street, showing elements such as the roadway, sidewalks, and gutters. The cross-sections provide a detailed view of the street’s shape and slope, which are key factors influencing how stormwater flows.

6. Assign specific Street cross-sections to individual street conduits: Each conduit in your street network should be assigned a specific cross-section from your collection created in the previous step. The assignment should accurately represent the actual structure of the street at the conduit's location.

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8. Create a collection of Inlet designs: After dealing with the streets, focus on creating a variety of inlet designs. These inlets are structures that allow stormwater to enter the drainage system from the street surface. They can have different designs depending on their size, shape, and the specific conditions they will be handling.

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10. Assign specific Inlet designs to selected streets: Once you have a collection of inlet designs, assign them to the specific streets within your network. Inlet placement depends on factors such as street slope, expected water flow, and city planning guidelines.

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12. Set appropriate analysis options and run a simulation: Configure the parameters for the SWMM analysis according to the objectives of your study, including the simulation duration, time steps, and any specific routing or runoff methods. Then, execute the simulation, which will use the SWMM algorithms to model how stormwater will flow through your designed network.

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14. Review the simulation results to see if flow spread and depth values are acceptable: After the simulation has run, assess the results. Examine key outputs like flow spread (the width of water flow on a street) and depth values at each inlet and node. Ensure that these values are within acceptable ranges as defined by your design standards. If the results are not satisfactory, you may need to revisit and revise your design, which may include altering the street layout, changing the assigned cross-sections, or modifying the inlet designs.

This detailed procedure offers a step-by-step guide to designing and analyzing a basic street and sewer drainage system using SWMM. It's essential to remember that real-world scenarios may require additional steps or considerations, depending on the specificities of the site, climate conditions, and regulatory requirements.

Inlets from the SWMM 5.2.3 help file

 Inlets from the SWMM 5.2.3 help file 

The Storm Water Management Model (SWMM) is a powerful hydrological simulation program, used for planning, analysis, and design related to stormwater runoff, combined sewers, sanitary sewers, and other drainage systems. This software models various components of these systems, including pipes, channels, and inlets. When modeling inlets with SWMM, you should consider the following key concepts:

1. Inlet Assignment: Inlets are assigned to conduit links that represent either streets or open channels. In this context, conduits are used to represent the physical structures that carry flow in the drainage system, such as pipes, channels, and tunnels. Therefore, each inlet, representing a point of entry for stormwater into the system, needs to be linked to a specific conduit.

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3. Inlet Type and Conduit Cross-section: The type of inlet you choose is determined by the cross-section of the conduit it is assigned to. For instance, curb and gutter-type inlets are designated to conduits with a street cross-section. Meanwhile, drop inlets are used with conduits that have either a rectangular or trapezoidal cross-section. Alternatively, custom inlets can be placed in any type of conduit, providing greater flexibility in modeling.

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5. Node Assignment: Each inlet is assigned to a node, typically part of a sewer line, that will receive the flow captured by the inlet. A node represents a junction point in the system where the flow may divide or combine.

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7. Multiple Inlets: Multiple inlets of the same design and receptor node can be assigned to a single conduit. This is particularly useful when modeling two-sided streets. For on-grade placement, the flow captured by each inlet is determined sequentially, which means the flow approaching the next inlet in line is the bypass flow from the inlet before it.

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9. Inlet Operation: Users can determine whether an inlet operates on-grade, on-sag, or let SWMM decide based on the street layout and topography. An on-grade inlet is situated on a continuous grade, while an on-sag inlet is located at a sag or sump point. The latter is an area where all adjacent conduits slope towards the inlet, leaving no place for water to flow except into the inlet.

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11. Flow Capture: Flow capture for on-grade inlets is determined by the approach flow seen by the inlet. However, for on-sag inlets, it is a function of the depth of water at the sag point node. This distinction is crucial for correctly modeling the flow behavior.

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13. Clogging and Flow Capture Restriction: Inlets can be assigned a degree of clogging and a flow capture restriction. These factors account for potential real-world conditions that may impede the flow into the inlet, providing a more accurate representation of the system’s functionality.