Automatic management of open water channels in storage critical conditions

Abstract

The invention discloses a water distribution system for controlling the delivery of water under gravity to at least one customer through a computer-controlled channel having a plurality of pools which are open conduits between respective upstream and downstream regulators and have both a hydraulic capacity and defined channel bank or maximum allowable operating level. The water distribution system has a multi-pool storage control system that reactively provides flow commands to control the opening of said regulators. The multi-pool storage control system determines the flow commands to coordinate multi-pool participation in balanced utilisation of distributed storage along sections of said channel to manage uncontrolled and uncertain system-level supply demand mismatch that cannot be eliminated through available control authority. The multi-pool storage control system operates without requiring direct measurement or forecasting of the supply-demand mismatch.

Description

[0001] AUTOMATIC MANAGEMENT OF OPEN WATER CHANNELS IN STORAGE CRITICAL CONDITIONS

[0002] FIELD OFTHE INVENTION

[0003] The invention relates to a water distribution system that uses a large-scale network of open channels or regulated rivers or streams to supply water under gravity. These systems transport the water via cascades of so-called pools linked by flow actuation structures in a relatively slow way compared to the nearly instantaneous response of a pressurized pipeline. More specifically, the invention provides a method to automatically coordinate multi-pool participation in balanced utilisation of distributed storage when storage critical supply-demand mismatch conditions arise at a system level. Feedback mechanisms enable this co-ordination objective to be achieved without requiring predictive supply-demand forecasting or direct measurement of the prevailing supply-demand mismatch conditions, although the availability of such can be leveraged for supervisory control to deliver multiple operating modes.

[0004] BACKGROUND OF THE INVENTION

[0005] The applicant is a world leader in gravity irrigation technology and has numerous patents in the field. These patents include the following Australian cases: AU2002233060 (Fluid regulation); AU2012289827 and AU2017203097 (Demand management system for fluid networks);

[0006] AU2018317494 (Method and system for water distribution and soil moisture determination); AU2014317812 (Method of demand management and control of fluid pipe networks); and AU2013243238 (Supervisory control of automated irrigation channels). To reduce the redundancy of description, the contents of these patents are incorporated herein, and familiarity with these contents is assumed.

[0007] As described in AU2013243238, the primary objective of AU2002223060 is to improve distribution efficiency whilst maintaining water levels along the channels above the levels required to provide adequate flow capacity under gravity. This is important in gravity systems as the potential energy available to produce flow along the channel itself, into lateral distribution systems, and onto the land to be irrigated, directly corresponds to the water levels in the channel, i.e., the maintenance of high and constant water level ensures a high and controllable flow onto the farm. An on-demand supply regime is the preferred configuration of an automated open channel network. Such a configuration provides the demand points that service, e.g., farms, and environmental systems, with the flow at the rate needed in response to end-user driven change of demand. Another possible configuration of a computer-controlled open channel network is supply driven. In such a configuration the supply of flow is set, and then distributed along the network to demand points. In such a configuration, some, or all the demand points are restricted to only taking the water at certain times when it aligns with the provided supply, hence this is not the preferred configuration.

[0008] Again, as described in AU2013243238, earlier patent AU2002223060 includes sensors and actuators linked through a Supervisory Control and Data Acquisition (SCADA) communication network, by automatic controllers that work in conjunction to achieve high distribution efficiency, reduce transmission losses (e.g., outflows at the end of the network), and provide a high level of service to the customer / farmer thereby enabling high productivity from water that is a limited resource. When a channel is fully automated, the channel control gates (i.e., regulators) are operated in such a manner to meet the water flow demand downstream of the control gates, and to maintain the water level upstream of the gate in every pool at desired values (i.e., set-points). A certain level of water must be exceeded in each pool to provide the potential energy needed to propel water further downstream, into secondary channels, and onto the adjacent farms. The volume of water flowing into the channel network is controlled at the upstream or top end supply point. There always needs to be a supply point at the top end. However, this may be supplemented from other controlled and uncontrolled supply points along the network, e.g., river inlets, off-stream storages, or drainage inlets. In the standard on-demand supply regime, the volume of water flowing into the channel is increased if a drop in the water level is sensed in a particular pool or is reduced if the water level rises to ensure a constant water level is maintained.

[0009] While AU2002223060 established effective local pool control, that achieves system-level supply-demand matching in steady state, it relies on reactive feedback control and assumes full authority over the top supply point and sufficient capacity in each pool to manage transient local mismatches. Subsequent work in AU2013243238 addressed transient performance and system-wide coordination by incorporating supervisory control layers that leverage preview of demand changes. However, both approaches assume either sufficient control authority to eliminate mismatches or reliable preview / measurement to anticipate them. Neither addresses the distinct challenge of managing sustained supply-demand mismatches when control authority is fundamentally limited and preview or measurement of the mismatch magnitude and duration is unavailable or unreliable.

[0010] “Control authority”, as used herein, refers to the physical ability of a control system to influence system behaviour through its actuators, constrained by factors including flow capacity limits of regulators, operational safety requirements, infrastructure limitations, and contractual supply / demand obligations. When system-level supply-demand mismatch exceeds available control authority, it cannot be eliminated regardless of control system sophistication.

[0011] Existing open channel control systems face significant limitations when managing supply-demand mismatch that lies beyond the available control authority for a sustained period across multi-pool sections (i.e., net mismatch across the section). These limitations become critical during sustained operational periods where available control authority cannot eliminate the mismatch even with complete knowledge of future conditions. Such mismatch results in consumption of stored water volume, or depletion of available storage capacity, at a corresponding rate.

[0012] Under sustained supply shortfall conditions, the stored water eventually decreases below a critical low level in at least one pool along the channel. This critical low level may be determined by various operational and safety factors including insufficient potential energy to maintain required off-take flows, water flow velocities that could cause erosion damage to earthen channel infrastructure, or other operational constraints specific to the channel design and safety requirements.

[0013] Similarly, under sustained excess supply conditions, the available storage eventually becomes insufficient in at least one pool to accommodate the excess inflow. This storage insufficiency may result in various critical conditions including overtopping that causes flooding of adjacent farms or infrastructure, bank erosion or structural damage from excessive water levels, exceeding hydraulic capacity limits of channel infrastructure, or exceeding regulatory limits that trigger mandatory environmental releases, premature discharge to receiving waters, flooding of adjacent properties, or violation of downstream flow agreements.

[0014] A key limitation of the standard reactive demand-driven controller architecture that is employed based on AU2002223060 is that this strategy assumes the system-level supply is fully controllable via the top (upstream) supply point. Sustained supply-demand mismatch may arise for the section of channel wheneverthis assumption fails to be the case.

[0015] However, under operating conditions with sustained net supply-demand mismatch, this assumption fails. Underthe standard demand-driven control strategy only the stored water or remaining capacity for storage of the top pool is available for consumption until it decreases below a critical level. This occurs without the participation of downstream pools, each of which remains at the nominal set-level for locally stored water as determined by a supervisory decision maker. This approach fails to utilise the collective storage capacity of the multi-pool system, leading to premature critical conditions and suboptimal resource utilisation.

[0016] Similarly, for a standard reactive decentralised supply-driven system a key limitation is that the system-level demand is assumed to be fully controllable by the bottom (downstream) demand point. Sustained supplydemand mismatch may arise for the section of channel wheneverthis assumption fails to be the case. Under conditions with sustained net supply-demand mismatch this assumption fails to hold. Only the stored water or remaining capacity for storage in the bottom pool is available for consumption, until it falls below a critical level. This occurs without the participation of upstream pools, each of which remains at the nominal setlevel for locally stored water set by a supervisory decision maker.

[0017] Limiting the consumption of stored water, or remaining capacity for storage to a single pool, fundamentally limits the supply-demand mismatch magnitude that can be sustained for a given period. To extend the capacity for accommodating water volume mismatch, the control system must be modified to enable the participation of additional pools. Participation of additional pools requires each of these to deviate from its set-point level. The participation may or may not be uniform across all additional pools, depending on their individual storage capacities, operational constraints, and current utilisation levels.

[0018] Enabling multi-pool participation in system-level supply-demand mismatch management presents two main technical challenges that are not addressed by existing open water channel control systems: 1) Mismatch Uncertainty: The system must automatically coordinate multi-pool participation to accommodate system-level supply-demand mismatch of uncertain magnitude or duration without requiring direct measurement orforecast of the mismatch. Existing predictive and supervisory control approaches require explicit knowledge of future supply-demand patterns and measurements of mismatch conditions. In addition, supervisory controllers require higher communication overhead and information requirements, and accurate models that operate over longer time scales to support slower decision-making processes. A reactive solution that is more robust to mismatch uncertainty than predictive and supervisory control approaches and that can be implemented in a decentralised way is preferred.

[0019] 2) Coordinated Recovery to Set-Points: The system should enable recovery of pool-by-pool water-level regulation to nominal set-levels when it becomes possible to set system-level supply-demand mismatch to zero.

[0020] Disclosed prior art including AU2002223060 does not provide a strategy for addressing these fundamental challenges. Predictive control systems require advance knowledge of supply-demand mismatch patterns that may not be available or reliable in practice.

[0021] Supervisory control systems, such as described in AU2013243238, rely on predetermined scheduling and optimization that cannot adapt to real-time mismatch conditions without explicit measurement or forecasting.

[0022] Additionally, supervisory control systems generally require centralised information processing and communication across spatially dispersed sensors and actuators, creating bandwidth limitations that force the supervisory layer to operate on slower timescales than the underlying control systems. These communication and computational requirements also create single points of failure where communication faults or computer failures cause the first control layer to return to lower layer objective which is typically to maintain fixed reference water levels, eliminating any multi-pool coordination capability.

[0023] Existing decentralized control systems, such as those described in AU2002223060, avoid the computational and communication overhead of supervisory systems, but limit storage utilisation to individual pools during transient local pool supply-demand mismatch. This prevents coordination of multi-pool participation in managing sustained system-level mismatch.

[0024] There exists a need for a control system that can automatically coordinate multi-pool participation in system-level supply-demand mismatch management without requiring direct measurement or forecasting of mismatch conditions, while providing coordinated recovery to desired operational set-points when mismatch conditions are resolved. Such a system would provide a supervisory decision maker (automated or human) more time to make critical operational decisions, prevent adverse outcomes such as service interruptions or infrastructure damage, and avoid the need for much more costly infrastructure solutions such as building large off-stream storage facilities. By utilising the existing distributed storage capacity within the channel network itself, such a system would maximize the value of existing infrastructure investments while providing enhanced operational flexibility and resilience. Preferably, such coordination is achieved through a decentralized control architecture that avoids the communication overhead and single points of failure inherent in supervisory systems while enabling the multi-pool participation that existing decentralized approaches cannot provide.

[0025] OBJECTS OF THE INVENTION

[0026] It is an object of the present invention to manage uncontrolled and uncertain system-level supply-demand mismatch in a water distribution system by using the inherent storage within the channel network.

[0027] Coordination of this distributed storage acts as a buffer to absorb or source the flow mismatch and enables operation close to the high level of service provided by prior art on-demand control systems during periods when such mismatch cannot be eliminated in a timely fashion through the available control authority.

[0028] SUMMARYOFTHE INVENTION

[0029] In one aspect of the invention there is provided a water distribution system for controlling the delivery of water under gravity to at least one customer through a computer-controlled channel, said channel having a plurality of pools which are open conduits between respective upstream and downstream regulators and have both a hydraulic capacity and defined channel bank or maximum allowable operating level; one of said pools having at least one lateral offtake to provide said delivery of water to said at least one customer; said water distribution system having a multi-pool storage control system that reactively provides flow commands to control the opening of said regulators; said multi-pool storage control system determines the flow commands to coordinate multi-pool participation in balanced utilisation of distributed storage along sections of said channel to manage uncontrolled and uncertain system-level supply demand mismatch that cannot be eliminated through available control authority; and wherein said multi-pool storage control system operates without requiring direct measurement or forecasting of the supply-demand mismatch.

[0030] In another aspect of the invention there may be provided a water distribution system for controlling the delivery of water under gravity to at least one customer through a computer-controlled channel, said channel having a plurality of pools which are open conduits between respective upstream and downstream regulators and have both a hydraulic capacity and defined channel bank or maximum allowable operating level; selected pools having at least one lateral offtake to provide said delivery of water to said at least one customer; said water distribution system having a multipool storage control system that reactively provides flow commands to control the opening of said regulators; said multi-pool storage control system determines the flow commands to coordinate multi-pool in balanced utilisation of distributed storage along sections of said channel to manage uncontrolled and uncertain system-level supply demand mismatch that cannot be eliminated through available control authority; and wherein said multi-pool storage control system operates without requiring direct measurement or forecasting of the supply-demand mismatch. In a preferred embodiment said multi-pool storage control system is configurable to utilise a selectable subset of said plurality of pools to accommodate system-level supply-demand mismatch based on design considerations for potential mismatch magnitude and duration and available storage capacity, and said multi-pool storage control system can weight individual pools according to their operational importance and constraints, with weights adjustable in real-time to accommodate changes in operational constraints.

[0031] The water distribution system may, in the absence of system-level supply / demand mismatch, allows the multi-pool storage control system to drive pool levels to steady-state values that are determined by the current flow regime and pool volume characteristics, but not necessarily returning to predetermined nominal set-points.

[0032] In one aspect whenever the required system-level supply or demand is available, the multi-pool storage control system may autonomously return the levels of the pools to a nominal operating depth.

[0033] Furthermore, said multi-pool storage control system may provide asymptotic convergence to coordinated balancing of deviations from setpoint across participating pools during sustained mismatch of uncertain magnitude and operates with a distributed architecture using only local sensor information from adjacent pools without requiring centralised communication or processing of system-wide data.

[0034] Preferably said multi-pool storage control system can interface with a supervisory control system allowing adjustments to set upstream supply and downstream demand within pre-defined constraints and / or adjustments to the references and balancing weights used by said multipool storage control system, while maintaining the capability for independent multi-pool coordination without supervisory control. The supervisory control system utilises precipitation measurements and hydrological models to forecast storm and / or rain water inflows into said channel and proactively adjusts the multi-pool storage control system parameters including reference levels and pool weights in advance of predicted storm events, enabling pre-emptive creation of storage capacity while maintaining minimum operational levels required for continued irrigation supply to unaffected areas. The interface between the supervisory control system and the multi-pool storage control system can be implemented through adjustment of the upstream supply flow alone, enabling the multi-pool storage control system to automatically coordinate pool levels in response to the resulting supply-demand mismatch without requiring direct communication of individual pool set-points or complex control calculations. The supervisory control system interfaces with a demand management system to implement demand rescheduling when the multi-pool storage control system indicates that maintaining hydraulic constraints requires temporary service modifications, with the extended time buffer provided by multi-pool coordination enabling negotiated demand adjustments rather than emergency curtailments.

[0035] The invention may also have selected pools from said plurality of pools can include delivery of water from a connected respective supplementary off-stream auxiliary water storage, and wherein said supplementary off-stream water storage can be controlled to provide supplementary water to its selected pool or provide all the water to said selected pool, and wherein said supplementary off-stream water storage may receive water from a selected pool for storage. In a further aspect of the invention said channel includes regulated gravity-fed open regulated waterways such as irrigation channels, rivers, streams, or stormwater management systems.

[0036] In yet a further aspect of the invention said multi-pool storage control system is configured to manage storm water surge events by coordinating available storage capacity across multiple pools to buffer unmeasured and unpredictable storm water inflows, preventing overtopping and infrastructure damage while minimizing uncontrolled releases to environmental receiving waters.

[0037] The invention may also provide a water distribution system for controlling the delivery of water under gravity to at least one customer through a computer-controlled channel, said channel having a plurality of pools which are open conduits between respective upstream and downstream regulators and have both a hydraulic capacity and defined channel bank or maximum allowable operating level; selected pools having at least one lateral offtake to provide said delivery of water to said at least one customer; said water distribution system having a multi-pool storage control system that reactively provides flow commands to control the opening of the regulators; said multi-pool storage control system determines the flow commands to utilize the distributed storage along sections of channel in a balanced way to compensate for the lack of full controllability of the supply and demand at the ends.

[0038] BRIEF DESCRIPTION OF DRAWINGS So that the invention may be readily understood and put into practical effect, reference will now be made to the accompanying drawings, in which:

[0039] Fig. 1 is a cross-sectional view of a typical channel used in this embodiment;

[0040] Fig. 2 is a longitudinal view of a section of the channel shown in Fig. 1 broken into interconnecting pools defined by upstream and downstream regulators;

[0041] Fig. 3A is a similar view to that of Fig. 2 under a supply driven strategy;

[0042] Fig. 3B is a similar view to that of Fig. 2 under a demand driven strategy; Fig. 3C is a similar view to that of Fig. 2 under the preferred operation of the invention;

[0043] Fig. 3D is a plan view of Fig. 3c showing the use of an off-stream auxiliary water storage;

[0044] Fig. 4 graphically shows simulated water-level responses along a section of the channel operating under a reactive demand driven way with a direct connection to a fixed supply inflow;

[0045] Fig. 5A graphically shows 3 participating pools in multi-pool storage control system leading to a substantial increase in time until critical levels reached and reduction in peak water level error compared to the direct connection of Fig. 4;

[0046] Fig. 5B graphically shows a similar view to that of Fig. 5Awith 5 participating pools in multi-pool storage control system leading to a further increase in time until critical level is reached and reduction in peak water level error; Fig. 5C graphically shows a similar view to that of Fig. 5Awith 10 participating pools in multi-pool storage control system leading to no violation of critical levels and a further reduction in peak water level error than that of Fig. 5B;

[0047] Fig. 5D shows 3 sections of channel with multi-pool storage interface section;

[0048] Fig. 6 is a diagram of components and systems making up the multi-pool storage control interface and how it connects with pre-existing interfaces; Fig. 7 is a diagram showing a distributed multi-pool storage controller with information flow between each controller;

[0049] Fig. 8 is a flow chart of a preferred embodiment showing operation one individual controller of the multi-pool storage control system detailed in Fig. 6;

[0050] Fig. 9 shows an interface controller architecture; and

[0051] Fig. 10 shows a flow chart showing the integration of the present invention with the inventions of the referenced prior patents.

[0052] DESCRIPTION OF PREFERRED EMBODIMENTS OFTHE INVENTION

[0053] Figs. 1 and 2 illustrate a prior art computer-controlled channel 10 forming the basis of the invention. Channel 10 forms part of a water distribution system using spatially large networks of open channel systems to supply water under gravity irrigation. Channel 10 has a trapezoidal cross-section with side walls 12, 14 and floor 16 but is not limited to this shape. Water flows along channel 10 at a minimum operational depth 18 and a maximum depth 20, but preferably at a nominal depth 22 with a freeboard 24 between a maximum depth 20 and a nominal depth 22. The minimum operational depth 18 is determined by requirements such as maintaining sufficient potential energy for off-take flows, system hydraulic stability, and service delivery obligations. The maximum operational depth 20 is determined by factors such as preventing overtopping, maintaining safe flow velocities, structural design limits, and regulatory constraints. In general, these operational depths can be time-varying e.g., if there is a known period of no operational orders then the nominal and minimum depth may be much lower, allowing for more flexible capacity.

[0054] Several regulators 26, 28, 30, and 32 are shown but the number and type of regulators are determined by the design and size of computer-controlled channel 10. Regulators 26, 28, 30, and 32 can be overshot gates as shown in AU2001283691 , or undershot gates as shown in AU2020365413 or US8602686, or combinations thereof, as typical, but non-limiting examples. The volume of water between neighbouring regulators provides defined pools 34, 36, and 38. For example, pool 34 will have an inlet regulator 26 and an outlet regulator 28, which pattern is repeated along channel 10. Each pool 34, 36, and 38 has a lateral offtake or pipes 40, 42, and 44 in the side wall(s) to allow a customer or farmer to distribute to land 46 to be irrigated. The land may be below or above the nominal supply level; when above the nominal supply level, typically a pump is required to extract the flow. In addition, there are drainage points 41, 43, 45 into pools 34, 36, 38 for surface water drainage. In this embodiment each pool has a lateral offtake / pipe / pump and drainage inlet but in practice there may be none or a plurality of offtakes / outlets / d rainage inlets, depending on requirements. Regulators 26, 28, 30, and 32 can each include a water level sensor device (not shown) to measure the depth of water 35, 37 and 39 within pools 34, 36, and 38. Metering (not shown) can be installed at lateral offtakes or pipes 40, 42, 44 or inlets or, at any position on each respective intended irrigation area to measure water flow for billing.

[0055] Problems arise with controlling the delivery of water to at least one customer through computer-controlled channel 10, where the regulators 28 and 30 are responsive to flow commands to control the flow of water along channel 10. Regulator 26 controls the most upstream inflow into channel 10 and may or may not be responsive to flow commands.

[0056] Regulator 32 controls the most downstream outflow of channel 10 and may or may not be responsive to flow commands. Channel 10 comprises a series of pools 34, 36 and 38 which are open conduits between pairs of regulators with each pool having a hydraulic capacity constrained by defined channel banks formed by side walls 12 and 14.

[0057] The customer offtakes 40, 42 and 44 deliver flow from channel 10 to the customer. These offtakes 40, 42 and 44 may require a minimum water level 18 in channel 10 to deliver the desired flow. In addition, computer-controlled channel 10 has a water level measurement in each pool 34, 36 and 38 and each in-line regulator 26, 28, 30 and 32 (with the potential exception of the first and last regulator), can be responsive to flow commands to control the flow of water along channel 10.

[0058] Customers along channel 10 may operate “on-demand”, i.e., they can start or stop taking water with little to no notice. The flow of water through each customer offtake (40,42 and 44) and each drainage inlet may or may not be measured in real time to be available to a control system 54 or 58 and may or may not be requested through a demand management system of the type shown in AU2017203097. Drainage inlets may supply water to pools from various sources including urban storm water drainage, on-farm drainage, and groundwater pumps. The customer supply point 40 (typically referred to as an outlet / turnout or offtake) supplies water for various purposes. Supply point 40 could deliver water to farms; for environmental purposes e.g., to a river; or for further distribution e.g., to distributary canal(s).

[0059] A desired objective in controlling this delivery is to maintain the water levels within the pools 34, 36 and 38 so that the customer offtake 40 flows are met, water level stays below the channel bank, and any additional hydraulic considerations are also met such as ensuring water velocities do not exceed thresholds which could cause physical damage to the channel 10 or bank.

[0060] The uncontrolled system-level supply-demand mismatch is the difference between net supply (sum of all flow entering channel 10 through regulator 26 and drainage inlets) and net demand (sum of all flows leaving channel 10 through outlets 40, 42, 44 and regulator 32) that cannot be eliminated through available control authority. Available control authority refers to the physical ability of the control system to influence system behaviour through its actuators, constrained by flow capacity limits, operational safety requirements, infrastructure limitations, and supply / demand obligations. Such mismatch results in consumption of stored water volume, or depletion of available storage capacity, at a corresponding rate. Under sustained mismatch conditions, the stored water, or available storage eventually causes water levels in at least one pool to drop below minimum operational depth 18 (insufficient stored water) or exceed maximum operating depth (insufficient available storage).

[0061] When system-level supply-demand mismatch exceeds available control authority, it cannot be eliminated regardless of control system sophistication. This fundamental limitation defines the operational scenarios where the present invention provides critical value.

[0062] Two primary existing control system strategies for computer-controlled channels are:

[0063] Supply-driven strategy: The inflow through regulator 26 is set to always ensure sufficient flow for all customers, and inline regulators 28, 30 and 32 react to pass only the excess flow. This strategy assumes that:

[0064] • Total supply is sufficient from regulator 26 to ensure adequate net supply for all outlets minus drainage inlets

[0065] • The outflow demand at regulator 32 can be fully controlled to manage system-level supply-demand mismatch

[0066] Demand-driven strategy: The upstream regulators 26, 28, 30 react to flows and levels downstream to respond to load changes. This strategy assumes that the upstream channel section inflow at regulator 26 is fully controllable to manage system-level supply-demand mismatch. Both strategies assume that available control authority is sufficient to eliminate system-level supply-demand mismatch. These strategies represent the prior art and are covered in AU2002223060. Under operating conditions with sustained system-level supply-demand mismatch, these assumptions fail to hold. For both strategies, the stored water or available storage consumed during mismatch events is predominantly utilised by a single pool, severely limiting the system's capacity to accommodate sustained mismatches.

[0067] Consequently, the time available for supervisory decision makers to react and correct the mismatch is limited by the time required to reach minimum operational depth 18 or maximum operational depth 20 in a single pool. This occurs without coordination from other pools: under demand-driven strategy, downstream pools remain at nominal levels; under supply-driven strategy, upstream pools remain at nominal operating levels.

[0068] These limitations either prevent automated solutions from operating under circumstances of sustained supply-demand mismatch, require extensive manual monitoring and human intervention to avoid serious adverse outcomes such as service interruptions, infrastructure damage, or safety violations, or lead to large infrastructure-based solutions such as building off-stream storages which have huge costs (financial, land acquisition, and environmental impacts).

[0069] Limiting the stored water, or available storage utilisation to what a single pool can provide limits the supply-demand mismatch magnitude and duration that can be sustained. To extend the system’s capacity to accommodate water volume mismatches, the control system must be modified to enable the participation of additional pools. Participation of additional pools requires each of these to deviate from its desired nominal level - something the current state-of the art systems actively attempt to prevent. The participation may or may not be uniform across all additional pools, depending on their individual storage capacities, operational constraints, and current utilisation.

[0070] As mentioned, previously, the supervisory layer described in

[0071] AU2013243238 could potentially help mitigate this. However, this approach requires reliable measurement or prediction of future conditions to coordinate control actions across pools and introduces substantial communication and computational overhead for system-wide optimization. These requirements have limited its adoption in practice for managing such operational scenarios.

[0072] Enabling multi-pool participation in system-level supply-demand mismatch management presents two critical technical challenges not addressed by existing control systems:

[0073] 1. Mismatch Uncertainty: The system must automatically coordinate multi-pool participation to accommodate system-level supplydemand mismatch of uncertain magnitude or duration without requiring direct measurement or forecast of the mismatch. The feedback controller responds to the effects of the mismatch through sensor measurements without needing to know directly what the mismatch is or what it will become. This reactive approach is inherently more robust to mismatch uncertainty than predictive and supervisory control approaches that require explicit knowledge of current and / or future system-level supply-demand mismatch patterns, which may be unavailable or unreliable in practice.

[0074] 2. Coordinated Recovery: The system must enable coordinated recovery of pool-by-pool water-level regulation to desired nominal operating levels when it becomes possible to control system-level supply-demand mismatch to zero through available control authority. This recovery must be automatically managed to avoid secondary disturbances and ensure smooth transition backto normal operational states across all participating pools.

[0075] Existing decentralized control systems avoid the computational and communication overhead of supervisory systems but lack coordination mechanisms for multi-pool participation. While decentralized architecture is preferred due to the limitations of supervisory systems, existing decentralized approaches cannot solve these fundamental coordination challenges.

[0076] The present invention addresses these limitations through a multi-pool storage control system that provides coordinated multi-pool participation in supply-demand mismatch management, preferably using a decentralized architecture. The system can operate without requiring direct measurement or forecasting of mismatch conditions, utilises only standard sensors for measuring pool levels and flows at in-line regulators, and provides coordinated recovery to normal operation when mismatch conditions are resolved. Consider the operational problem of managing sustained uncontrolled and uncertain system-level supply-demand mismatch. Such mismatch arises when demand outlets within the channel section operate in demand-driven mode where customers can initiate or cease water extraction with little to no notice, and this demand has limited controllability (which includes limited ability to schedule or adjust the timing of demand). Additionally, there is limited control authority of the upstream supply source to adjust flow due to limitations such as constraints on frequency and accuracy of inflow adjustments imposed by regulatory oversight, infrastructure limitations, uncontrolled inflows from storm events, or competing operational objectives such as managing transient flow amplification effects upstream.

[0077] When excess demand occurs in the system this requires the depletion of stored water within the channel section. When excess supply occurs, this requires storage of additional water within the channel section. The objective of the multi-pool storage control system is to coordinate the utilisation of stored water and available storage capacity across multiple pools to provide time for either the mismatch conditions to resolve naturally or for supervisory decision makers to implement corrective actions before adverse effects occur - such as pools reaching minimum operational depth 18 or maximum operational depth 20, or other critical operational limits.

[0078] The coordination of multiple pools enables more effective management of supply-demand mismatch while considering available in-line storage constraints and operational preferences for individual pools. Fig. 3A illustrates a scenario with sustained excess demand resulting in uncontrolled negative system-level supply-demand mismatch using a state-of-the-art supply-driven control system. In supply-driven mode, upstream pools 34 and 36 remain at nominal operating levels while stored water is consumed predominantly from a single pool — typically the most downstream pool 38, as shown by reduced depth 48 compared to nominal operating depth 39. This approach means the magnitude and duration of mismatch that can be safely accommodated is limited by the water stored in only one pool, while underutilising available stored water in other pools that remain at or near nominal operating levels.

[0079] Fig. 3B shows the same mismatch scenario under a state-of-the-art demand-driven control strategy. In this case, stored water is consumed primarily from the upstream pool 34, causing water level to drop as shown by reduced depth 50 compared to nominal operating depth 35, while downstream pools 36 and 38 remain at or near nominal operating levels.

[0080] In both conventional strategies, the time until at least one pool reaches minimum operational depth 18 is constrained by the storage capacity of a single pool. This represents a fundamental limitation of existing approaches that fail to utilise the distributed storage capacity available across the channel network.

[0081] Fig. 3C depicts the operation of the multi-pool storage control system of the present invention. Under the same sustained excess demand conditions, water levels 35, 37, and 39 in all pools remain above minimum operational depth 18 but operate below nominal depth 22. No individual pool reaches minimum operational depth 18, thereby providing extended time for either mismatch conditions to resolve or for supervisory decision makers to implement corrective actions before adverse effects occur. This coordinated approach increases utilisation of available storage capacity across the channel network.

[0082] A similar situation arises during sustained excess supply conditions. Using existing control strategies, pools at the extremes of the channel section (either upstream or downstream, depending on strategy) reach their maximum operational limits first while other sections retain spare storage capacity, creating risk of premature infrastructure damage through overtopping or structural stress.

[0083] With the proposed multi-pool storage control system, pools are coordinated to share the burden of managing system-level supply-demand mismatch. During excess supply conditions, water levels in participating pools rise collectively by smaller individual amounts compared to scenarios where a single pool accommodates all excess supply. This coordinated approach maintains all pools within their operational limits (between minimum operational depth 18 and maximum operational depth 20) for extended periods, preventing or at least providing more time before localised critical conditions occur while increasing effective use of available storage capacity throughout the channel network.

[0084] Fig 3D shows a schematic view of channel 10 where there is a supplementary off-stream water storage 110. The supplementary off- stream storage 110 has an inlet 112 that allows flow from channel 10 into storage 110 from pool 36 and has an outlet 114 that that allows flow from storage 110 into pool 38. Electronically controlled valves, gates or pumps 116, 118 allow flow in and out of storage 110. In the situation where there is excess upstream supply and there is storage capacity in off-stream storagel 10, then the storage inlet 112 can be coordinated with the inline regulators 28, 30 to more fairly distribute the excess water not only across the pools 36; 38 but also in the off-stream storage 110. Similarly in the case where there is excess demand / shortfall in supply then the storage outlet 118 can be used in coordination with regulators 28 and 30 to use the off-stream storage 110 and inline channel storage to continue to meet downstream demand.

[0085] Fig. 4 demonstrates simulated water-level responses along a section of channel 10 comprising a 33-pool system operating under demand-driven control (distant downstream control), with the upstream regulator lacking control authority and maintaining fixed supply inflow up until the 96 hour mark, after which control authority is obtained. This configuration is representative of many real-world distribution systems globally, including those in Australia and the USA, where supply inflow is predetermined and fixed, often days in advance, by a different authority than the one operating the distribution network.

[0086] The simulation examines system response to the following demand profile, which creates sustained periods of uncontrolled system-level supplydemand mismatch:

[0087] Time Period Demand Condition System-Level Mismatch

[0088] 0-24 hours Equal to supply inflow Balanced condition

[0089]

[0090] 24-48 hours Demand reduction Excess supply (positive mismatch)

[0091] 48-84 hours Demand increase Supply shortfall (negative mismatch)

[0092] 96-144 Control authority Zero mismatch in steady state hours resumed at supply point,

[0093] demand

[0094]

[0095] This configuration represents a scenario where the supply source is subject to control authority limitations, resulting in sustained system-level supplydemand mismatch periods. Under demand-driven operation, only the stored water and available storage capacity of the upstream pool (Pool 1 ) are utilised during mismatch conditions.

[0096] Excess Supply Period (24-48 hours): When demand drops below fixed supply inflow, Pool 1 accumulates the excess water. Assuming maximum operational depth is 0.2m above nominal operating level, Pool 1 exceeds this threshold at the 28.75-hour mark (4.75 hours after demand reduction begins). Without intervention, continued water level rise would likely cause infrastructure damage through overtopping or structural stress.

[0097] Supply Shortfall Period (48-84 hours): When downstream demand exceeds fixed supply inflow, Pool 1 initially provides the shortfall, similar to the scenario illustrated in Figure 3B. Pool 1 drops 0.2m below nominal operating depth at the 68-hour mark, restricting service delivery to downstream customers and causing Pools 2 and 3 to also drop below nominal depth as they attempt to maintain downstream service. Throughout this period, the remaining pools operate at or very close to nominal operating depth, providing no stored water or available capacity during mismatch periods.

[0098] The following scenarios demonstrate how coordinating multiple pools can increase available storage capacity and extend operational time before critical conditions occur:

[0099] Fig. 5A-Three-Pool Coordination: When three pools participate in the multi-pool storage control system, the system achieves an additional 4.33 hours before any pool exceeds 0.2m above nominal operating level, compared to the single-pool approach shown in Figure 4. Additionally, the peak deviation from nominal operating level is reduced by greater than 50%, demonstrating more effective distribution of storage burden across participating pools.

[0100] Fig. 5B - Five-Pool Coordination: With five pools participating in the multipool storage control system, the critical threshold is not crossed until the 48-hour mark — a further 10 hours beyond the three-pool scenario in Figure 5A. This configuration achieves greater than 80% reduction in peak deviation from nominal operating depth compared to the single-pool limitation shown in Figure 4. Upon obtaining control authority at the 96-hour mark, the system automatically restores all pool levels to nominal operating depth.

[0101] Fig. 5C -Ten-Pool Coordination: When ten pools participate in the multipool storage control system, no pools exceed 0.2m deviation from nominal operating depth in either direction throughout the entire simulation period. This demonstrates that the system can sustain this scenario of supplydemand mismatches without requiring supervisory intervention or experiencing adverse operational effects. Upon obtaining control authority at the 96-hour mark, the system automatically restores all pool levels to nominal operating depth without operator intervention, demonstrating the system's autonomous control capability.

[0102] In large channel systems consisting of many pools operating under reactive demand-driven control, the amplification of peak transient gate flows upstream of demand changes can exceed actuator limits, leading to performance degradation as described in AU2013243238. A key approach to managing this issue involves buffering the upstream propagation of downstream transients at strategic points within the channel using available storage capacity.

[0103] Traditional solutions require building costly off-stream storage facilities and integrating them appropriately into the control system. The multi-pool storage control system of the present invention provides an alternative approach by utilising stored water and available storage capacity within the existing channel infrastructure itself, reducing or eliminating the need for additional construction.

[0104] Fig 5D illustrates such a segmented configuration, where channel 10 is divided into three operational sections:

[0105] Upstream section 100: Operates under reactive demand-driven control • Middle section 104: Operates using multi-pool storage control system

[0106] • Downstream section 102: Operates under reactive demand-driven control

[0107] The regulator at the boundary between section 100 and section 104 has control authority to manage system-level supply-demand mismatch for the middle section. Because the coordinated pools in Section 104 provide greater effective storage capacity, the flow dynamics can be managed more effectively. With appropriate design and selection of the multi-pool storage control system for the section 104 and controller design to determine the flow commands for the inflow regulator to this section, flow transients and overshoots are smoothed out to provide a more manageable demand pattern for the upstream section 100, while maintaining good service levels (minimal deviation from nominal operating depth) within section 104.

[0108] Each section (100, 102, and 104) contain multiple regulators for local operation, but section 104 additionally employs the multi-pool storage control system to coordinate storage utilisation across its pools. This coordinated approach serves as a hydraulic buffer that:

[0109] • Absorbs downstream propagation of upstream transients before they propagate downstream

[0110] • Smooths flow variations to reduce actuator stress

[0111] • Maintains service quality within section and assists improving service quality upstream section by buffering the upstream propagation of downstream transients Utilises existing infrastructure rather than requiring new storage construction

[0112] This segmented approach demonstrates the flexibility of the multi-pool storage control system to serve as an interface between different control strategies. Similar storage interface functionality is applicable for:

[0113] • Supply-driven upstream sections interfacing with demand-driven downstream sections

[0114] • Different operational zones with varying control objectives or constraints

[0115] The multi-pool storage control system thus provides a versatile solution for managing hydraulic interfaces in complex channel networks while utilising existing distributed storage capacity.

[0116] Another scenario where uncontrolled system-level supply-demand mismatch occurs is when irrigation channel 10 faces storm surge conditions that cause significant overflow of water into the network, potentially from urban storm drainage systems. When storm water inflow exceeds demand within the affected channel section, this creates an excess supply scenario with potentially severe consequences.

[0117] In such situations, the operational objectives include:

[0118] • Store and buffer storm water within the existing channel network capacity

[0119] • Prevent infrastructure damage from overtopping and excessive flow velocities

[0120] • Minimise polluted and high-flow releases into environmental streams and receiving waters

[0121] • Maintain system operational capability during and after storm events Because environmental discharge capacity is constrained and not fully controllable, and storm water supply is inherently uncontrollable, this represents a classic uncontrolled system-level supply-demand mismatch scenario. Storm water inflow points are often unmeasured, and weather forecasts may provide limited accuracy or insufficient lead time for timely predictive control.

[0122] The multi-pool storage control system provides an effective solution for storm water management by coordinating available storage capacity across multiple pools to buffer incoming storm flows. This approach offers several advantages:

[0123] Increased Storage Utilisation: Rather than overwhelming individual pools near storm water entry points, the system automatically coordinates storage across multiple pools, significantly increasing effective buffering capacity within existing infrastructure.

[0124] Infrastructure Protection: By distributing storm water storage burden across multiple pools, the system prevents individual pools from exceeding maximum operational depth 20, reducing risk of overtopping, bank erosion, and structural damage.

[0125] Predictable System Response: The coordinated storage approach creates more predictable hydraulic behaviour that can be more reliably modelled, providing better interface capability with supervisory control systems (such as those described in AU2013243238) that may utilise longer-term weather forecasts and optimization algorithms.

[0126] Extended Decision Time: By effectively utilizing distributed storage capacity, the system provides supervisory decision makers significantly more time to implement corrective actions. This includes time for human operators to coordinate with upstream authorities or activate emergency protocols, as well as time for automated supervisory layers (which often operate on slower time scales due to information-intensive and optimization-based approaches) to process forecasts, optimize system-wide responses, and implement coordinated control actions before critical conditions develop.

[0127] This application addresses critical environmental and regulatory compliance requirements, namely:

[0128] • Pollution control through reduced uncontrolled releases to environmental waters

[0129] • Flow management to protect downstream ecosystems from damaging flow spikes

[0130] • Infrastructure resilience to climate change and extreme weather events

[0131] • Regulatory compliance with storm water management and environmental protection requirements

[0132] The multi-pool storage control system thus provides a cost-effective alternative to constructing dedicated storm water detention facilities while utilising existing channel infrastructure more effectively during extreme weather events.

[0133] Integration with Predictive Supervisory Control for Dual-Mode Operations

[0134] While the multi-pool storage control system operates autonomously as a reactive Level 1 controller, a further embodiment incorporates integration with an optional predictive supervisory control layer to enhance system performance during anticipated storm events in dual-purpose canal networks. These networks, common in reclaimed agricultural areas globally, serve the dual function of drainage during wet periods and irrigation supply during growing seasons. Climate change has increased the occurrence of localised storm activity during irrigation operations, creating operational challenges where the system must simultaneously accommodate storm drainage inputs while maintaining irrigation supply through the same infrastructure.

[0135] Supervisory Enhancement Architecture

[0136] In this embodiment, the supervisory control layer operates as described in AU2013243238 but with specific enhancements for coordinating with the multi-pool storage control system during dual-mode operations. The supervisory layer utilises multiple data sources to anticipate and prepare for storm inflows:

[0137] 1. Precipitation Monitoring and Forecasting: Field weather stations, such as those described in AU20210026040, provide high-accuracy, real-time precipitation measurements across micro-catchments associated with drainage inflow points. These measurements enable:

[0138] o Unit hydrograph calculations to forecast resultant flows from individual catchments based on measured precipitation intensity and duration

[0139] o Calibration of global climate forecast models to improve location-specific weather predictions

[0140] o Real-time validation of forecast accuracy as storm events

[0141] develop 2. Demand Prediction Integration: The supervisory system incorporates demand forecasting methods from prior art, including:

[0142] o Soil moisture deficit calculations to predict irrigation demand from individual turnouts e.g., using techniques such as those described in AU20210127605

[0143] o Model predictive control techniques to anticipate system-wide demand patterns

[0144] o Integration of these demand predictions with storm inflow forecasts to determine net system-level supply-demand mismatch scenarios

[0145] Proactive Storage Optimization

[0146] With forecast information available, the supervisory control layer proactively configures the multi-pool storage control system before storm arrival through the following control strategy:

[0147] a) Anticipatory Drawdown: The supervisory system calculates optimal pre-storm water levels across participating pools, lowering levels to create additional storage capacity while maintaining minimum depths required for irrigation supply.

[0148] b) Supply Flow Coordination: The supervisory layer coordinates with upstream water supply infrastructure to reduce or cease supply flows from upstream dams or reservoirs in advance of storm events.

[0149] c) Demand Management: When temporary capacity reduction from preventive drawdown affects irrigation service levels, the supervisory system implements demand rescheduling through communication with affected customers. d) Downstream Release Coordination: The supervisory system manages controlled releases to downstream hydrologic systems within capacity constraints.

[0150] Simplified Interface Design for Multi-Pool Storage Control

[0151] A key advantage of the multi-pool storage control system is that it dramatically simplifies the interface requirements between channel sections operating under different control strategies or authorities. Unlike complex supervisory systems requiring extensive communication and computational infrastructure, the multi-pool storage interface can be implemented through simple flow adjustments that can be executed by either automated systems or human operators.

[0152] At its most basic implementation, activating multi-pool storage coordination requires only a single control action: adjusting the inflow rate at the upstream boundary of the multi-pool section. When inflow is reduced below the downstream demand, the multi-pool storage control system automatically coordinates the controlled drawdown across participating pools without requiring any additional commands or measurements. This simplification enables:

[0153] 1. Human Operator Compatibility: A human operator can initiate coordinated storage preparation by simply reducing the upstream supply gate opening, without needing to understand or calculate individual pool set-points or coordination algorithms.

[0154] 2. Minimal Communication Requirements: Unlike MPC-based solutions requiring continuous data exchange and optimization calculations as described in AU2013243238, the basic interface needs only a single flow command that can be transmitted through existing SCADA systems or even implemented through manual gate adjustments. Progressive Interface Enhancement

[0155] While the basic flow-control interface provides robust operation, progressively sophisticated enhancements can be added without compromisingthe fundamental simplicity:

[0156] Level 1 - Basic Flow Control: Adjust upstream inflow rate only

[0157] Level 2 - Constraint-Based Tuning: Adjust pool weights to reflect operational constraints

[0158] Level 3 - Dynamic Reference Adjustment: Modify reference levels to achieve specific drawdown targets

[0159] Level 4 - Full Supervisory Integration: Real-time optimization of all parameters based on forecasts

[0160] The multi-pool storage control system provides both extended time and suitable control interfaces for operators or supervisory controllers to manage hydraulic constraints. Beyond the primary supply flow adjustment at the upstream boundary, the system provides multiple interface mechanisms that supervisory controllers can utilise to maintain hydraulic constraints. These include, but are not limited to:

[0161] 1. Reference Level Adjustment: Water level references have direct, predictable relationships to channel capacity and off-take service levels, enabling supervisory controllers to maintain minimum service levels for critical off-takes.

[0162] 2. Weight Configuration: Pools with different operational constraints receive appropriate weights reflecting their limitations, with weights dynamically adjustable as operational constraints change. 3. Demand Management Integration: Interface with Demand Management Systems as described in AU20140379143, AU20170147010 and AU 20160209851 enables proactive demand shaping before capacity constraints are reached.

[0163] 4. Additional Control Parameters: Flow setpoint adjustments at intermediate regulators, feedforward components, and other implementation-specific parameters.

[0164] Operational Example - Localised Storm During Irrigation Season Consider a 50-pool irrigation channel where forecast indicates a severe thunderstorm will impact pools 15-25 in approximately 6 hours, requiring an estimated 20ML of storage capacity.

[0165] Without Multi-Pool Storage Control Interface (Traditional Approach):

[0166] Operators would face an overwhelming coordination challenge:

[0167] • Calculate individual water level adjustments for each of the 20 affected pools

[0168] • Manually adjust flow set-points at 20+ inline regulators in sequence • Account for hydraulic travel times and pool interactions in calculations

[0169] • Continuously monitor and readjust each regulator as conditions change

[0170] • Require accurate hydraulic models to predict pool-by-pool responses

[0171] • Make frequent adjustments (every 15-30 minutes) as upstream changes propagate

[0172] • Coordinate timing to avoid hydraulic oscillations between pools Risk service interruptions if calculations are incorrect or adjustments mistimed

[0173] This complexity often leads operators to adopt overly conservative strategies such as:

[0174] • Draining pools far below necessary levels, interrupting service to customers

[0175] • Releasing excessive volumes downstream as a precaution, wasting water and potentially causing downstream flooding

[0176] • Focusing on single-pool management near expected inflow points, rapidly exhausting local storage

[0177] • Avoiding preparation entirely, accepting infrastructure damage risk rather than attempting error-prone manual coordination

[0178] These conservative approaches either compromise service quality unnecessarily or fail to utilise available storage capacity, resulting in preventable infrastructure damage or environmental releases.

[0179] With Multi-Pool Storage Control Interface (Present Invention): The same operator can achieve superior outcomes with a simple approach:

[0180] 1. Determine storage requirement: 20ML needed, requiring pools 10-30 to participate while maintaining service levels (a manageable calculation once system parameters are established)

[0181] 2. Reduce upstream supply gate to pools 10-30 by calculated amount (single adjustment)

[0182] 3. Multi-pool storage control system automatically coordinates all 20 pools

[0183] 4. System maintains balanced drawdown without further intervention 5. If storm delivers 10 ML or 30 ML instead of forecast 20 ML, system automatically accommodates the variation

[0184] 6. Operator returns supply gate to normal after storm passes

[0185] The critical distinction is that the operator needs only a rough volume estimate rather than precise pool-by-pool calculations. The multi-pool storage control system provides robustness to forecast uncertainty; the coordinated pools accommodate the variation without operator intervention. This transforms an intractable manual coordination problem requiring accurate models and continuous adjustment into a simple volume-based decision that can be executed by operators with basic training.

[0186] For supervisory systems utilising precipitation data from weather stations (AU20210026040) and soil moisture deficit calculations (AU20210127605), this simplified interface means optimization algorithms can focus on strategic decisions (how much capacity to create) rather than tactical implementation (how to coordinate dozens of regulators). This approach provides robustness whether operated by sophisticated MPC algorithms (AU2013243238) or basic human intervention.

[0187] The integration between supervisory and multi-pool storage control layers operates through defined interfaces while maintaining operational independence. If supervisory communication fails or forecasts prove inaccurate, the Level 1 multi-pool storage control system continues coordinating storage based on actual measured conditions, providing robust fallback operation. This hierarchical approach leverages predictive capabilities when available while maintaining robust reactive control for unpredictable conditions. The multi-pool storage control system provides autonomous recovery capability, automatically returning storage to desired volumes and nominal operating depths in each pool when control authority becomes available to eliminate the system-level supply-demand mismatch at the upstream boundary. This recovery process occurs without requiring manual intervention or supervisory scheduling, enabling seamless transition back to normal operational states.

[0188] In many applications, it is desirable to keep worst-case deviation from nominal operating depth as small as possible across all participating pools. One embodiment achieves this objective by coordinating weighted level deviations to track together, ensuring no single pool experiences worse conditions than others. This balanced approach provides the additional advantage of maintaining maximum available capacity for further unpredictable mismatches that might occur anywhere along the channel section, since all pools retain similar unused storage margins.

[0189] The ability to weight pools according to their individual characteristics is important because pools may have different minimum and maximum operating depths, storage capacities, and operational constraints. The weighting system allows the coordination algorithm to account for these differences while maintaining effective overall system performance.

[0190] Alternative embodiments may distribute storage and capacity utilisation in temporal sequences, such as utilising one pool until it approaches operational limits, then transitioning to another pool in a defined sequence. This sequential approach may be preferred in scenarios where preserving nominal operating conditions in certain pools takes priority, or where operational constraints favour staged utilisation of available storage capacity.

[0191] The main components of the present invention are shown in Fig. 6, comprising a multi-pool storage control interface 52 with three integrated modules:

[0192] (1) Level 1 Multi-Pool Storage Control System - The Level 1 Multi-Pool Storage Control System 54 implements algorithms providing a reactive mechanism for responding to uncontrolled and uncertain system-level supply-demand mismatch by measuring and reacting to water levels and flows. The system asymptotically achieves desired coordination objectives, such as minimizing maximum deviations from nominal operating depths across participating pools, enabling pools to be managed as collective storage capacity.

[0193] The Level 1 Multi-Pool Storage Control System 54 reactively measures pool conditions and calculates regulator positions to coordinate flows and levels across pools in the multi-pool storage section. Figure 8 provides a flow chart for an individual controller within the distributed network architecture.

[0194] Distributed Control Implementation: In the preferred embodiment using distributed control architecture, the Level 1 Multi-Pool Storage Control System is implemented in SCADA computers at each regulator location. Through cooperative communication with neighbouring sites only, the system achieves overall coordination using the following sequence:

[0195] (a) Measure water level using sensors at each pool

[0196] (b) Calculate weighted level error using weights and references that may be provided by supervisory decision makers / controllers.

[0197] (c) Communicate weighted level error to upstream neighbouring controller (i-1 in Fig. 7).

[0198] (d) Receive weighted level error from downstream neighbouring controller (i+1 in Fig. 7).

[0199] (e) Perform controller calculations, including calculating differences between local and downstream weighted errors, then executing discretised control updates with integral action. (f) Regulate flow through regulator to achieve desired flow setpoint using sensors, flow calculation algorithms, and actuators as described in AU2002233060.

[0200] (2) Channel storage specification (Design Tool)- Channel Storage Specification Module 60 is a design and analysis tool (not part of the real-time control system) that processes model information from pre-existing pool construction modules 62 to support system design and configuration. This module provides information used during the design phase of the Level 1 control system and can also supply storage capacity data to supervisory control systems for optimization purposes. Module 60 performs the following functions:

[0201] (a) Define source limitations including upstream supply constraints and available control authority (b) Determine channel storage models using Pool Construction Model 62, incorporating allowable operating ranges for each pool as depicted in Fig. 1.

[0202] (c) Calculate maximum available storage across the channel section, including any off-stream storage facilities, to establish constraints on the maximum supply-demand mismatch magnitude that can be buffered while maintaining the system within operational limits.

[0203] These calculated constraints serve multiple purposes:

[0204] • Design Decision Support: Determining how many pools need to participate in the multi-pool storage control system to handle expected mismatch scenarios

[0205] • Supervisory System Planning: Providing capacity limits to supervisory controllers for optimization algorithms and operational planning • Operational Monitoring: Establishing thresholds for alerting operators when system approaches storage capacity limits

[0206] • Risk Assessment: Quantifying how long the system can sustain various mismatch magnitudes before reaching critical levels, enabling proactive decision-making

[0207] For example, if analysis shows the system can buffer a 50 ML / day mismatch for 6 hours with 5 participating pools, but only 2 hours with 3 pools, this informs both the initial system design (how many pools to include) and real-time supervisory decisions about when intervention is needed.

[0208] (d) Optimize pool participation by adjusting the number of participating pools based on mismatch buffering requirements - if conservative mismatch constraints are acceptable, fewer pools need participate, allowing more pools to operate under standard demand-driven control (as demonstrated in Figures 5A-5C, showing reduced deviations for identical mismatch conditions as participating pools increase from 3 to 5 to 10)

[0209] (3) Design of Level 1 Control System - Design Module 64 provides systematic design processes for the Level 1 Multi-Pool Storage Control System 54, ensuring asymptotic convergence to coordinated balancing objectives and enabling decentralised implementation. The design process ensures Level 1 Multi-Pool Storage Control System 54 operates as a reactive interface controller that coordinates flows between participating pools based on real-time water level measurements and other relevant parameters, achieving coordinated balancing of deviations from setpoint across the collection of pools during sustained supply / demand mismatches.

[0210] a. Decentralized Architecture: The preferred implementation uses distributed interface controller structure where flow between each pair of pools is determined based on local measurements of neighbouring controller information such as upstream and downstream water-level errors. Fig 7 illustrates this distributed architecture and information flow between local interface controllers.

[0211] b. Integral Control Action: One embodiment employs integral action to achieve water-level error coordination objectives, where deviations from nominal operating depth in participating pools track together, and in the absence of mismatch conditions, deviations converge to specified constants relative to operational requirements. c. Neighbouring Pool Coordination: An embodiment uses sensor measurements of levels and references to calculate differences between weighted water level errors of neighbouring pools (depicted as solid lines in Figure 7). Regulating these differences couples pools together to operate as collective storage, enabling coordinated tracking of deviations to achieve system-wide consensus.

[0212] d. Autonomous Mismatch Management: Embodiments may include control systems for upstream supply points or downstream demand points to autonomously manage supplydemand mismatch to desired levels when available control authority exists (such as zero mismatch), achieving steadystate operation with pools at nominal operating levels. e. Enhanced Control Inputs: The Level 1 controller 64 may incorporate additional inputs for feedforward control components, including flows from neighbouring pools, components of neighbouring pool controller outputs, or inputs from supervisory computer control systems measuring realtime inflows and outflows within the network section. Feedforward components may include gains and low-pass filters on input signals (optional feedforward components are depicted as dashed lines in Fig 7).

[0213] (4) Supervisory Control Interface: The multi-pool storage control system provides multiple interface points for optional integration with supervisory control systems 58, while maintaining capability for autonomous operation: a. Flow Management Interface: Supervisory systems can adjust supply flows at upstream boundaries and demand flows at downstream boundaries within pre-defined operational constraints, enabling coordinated system-wide optimization when control authority is available.

[0214] b. Pool Weighting Interface: Real-time adjustment of relative weights for each participating pool, allowing supervisory systems to prioritize certain pools based on operational requirements, maintenance schedules, or service level agreements.

[0215] c. Reference Level Interface: Adjustment of nominal operating depths / set-points for each pool, enabling supervisory systems to modify target levels based on forecasted conditions, seasonal variations, or operational mode changes. d. Constraint Communication: The system can report current storage utilization and available capacity to supervisory layers, enabling better-informed optimization decisions at longer time scales.

[0216] Fig. 10 is a flow chart showing the integration of the present invention with the inventions of the referenced prior patents. The listed patents are all Australian patents except for US 8602686.

[0217] The invention will be understood to embrace many further modifications as will be readily apparent to persons skilled in the art and which will be deemed to reside within the broad scope and ambit of the invention, there having been set forth herein only the broad nature of the invention and specific embodiments byway of example.

Claims

The claims defining the invention are as follows:

1. A water distribution system for controlling the delivery of water under gravity to at least one customer through a computer- controlled channel, said channel having a plurality of pools which are open conduits between respective upstream and downstream regulators and have both a hydraulic capacity and defined channel bank or maximum allowable operating level; one of said pools having at least one lateral offtake to provide said delivery of water to said at least one customer; said water distribution system having a multi-pool storage control system that reactively provides flow commands to control the opening of said regulators; said multi-pool storage control system determines the flow commands to coordinate multi-pool participation in balanced utilisation of distributed storage along sections of said channel to manage uncontrolled and uncertain system-level supply demand mismatch that cannot be eliminated through available control authority; and wherein said multi-pool storage control system operates without requiring direct measurement or forecasting of the supply-demand mismatch.

2. A water distribution system for controlling the delivery of water under gravity to at least one customer through a computer- controlled channel, said channel having a plurality of pools which are open conduits between respective upstream and downstream regulators and have both a hydraulic capacity and defined channel bank or maximum allowable operating level; selected pools having at least one lateral offtake to provide said delivery of water to said atleast one customer; said water distribution system having a multipool storage control system that reactively provides flow commands to control the opening of said regulators; said multi-pool storage control system determines the flow commands to coordinate multi-pool participation in utilising distributed storage along sections of said channel to manage uncontrolled and uncertain system-level supply demand mismatch that cannot be eliminated through available control authority; and wherein said multi-pool storage control system operates without requiring direct measurement orforecasting of the supply-demand mismatch.

3. The water distribution system of claim 1 or 2, wherein said multipool storage control system is configurable to utilise a selectable subset of said plurality of pools to accommodate system-level supply-demand mismatch based on design considerations for potential mismatch magnitude and duration and available storage capacity, and said multi-pool storage control system can weight individual pools according to their operational importance and constraints, with weights adjustable in real-time to accommodate changes in operational constraints.

4. The water distribution system of any one of claims 1 to 3, wherein, in the absence of system-level supply / demand mismatch, the multipool storage control system drives pool levels to steady-state values that are determined by the current flow regime and pool volume characteristics, but not necessarily returning to predetermined nominal set-points.

5. The water distribution system of any one of the preceding claims, wherein where the required system-level supply or demand isavailable, the multi-pool storage control system may autonomously return the levels of the pools to a nominal operating depth.

6. The water distribution system of any one of the preceding claims, wherein said multi-pool storage control system provides asymptotic convergence to coordinated balancing of deviations from setpoint across participating pools during sustained mismatch of uncertain magnitude, and operates with a distributed architecture using only local sensor information from adjacent pools without requiring centralised communication or processing of system-wide data.

7. The water distribution system of any one of the preceding claims, wherein said multi-pool storage control system can interface with a supervisory control system allowing adjustments to set upstream supply and downstream demand within pre-defined constraints and / or adjustments to the references and balancing weights used by said multi-pool storage control system, while maintaining the capability for independent multi-pool coordination without supervisory control.

8. The water distribution system of claim 7, wherein the supervisory control system utilises precipitation measurements and hydrological models to forecast storm and / or rain water inflows into said channel, and proactively adjusts the multi-pool storage control system parameters including reference levels and pool weights in advance of predicted storm events, enabling pre-emptive creation of storage capacity while maintaining minimum operational levels required for continued irrigation supply to unaffected areas.

9. The water distribution system of claim 7 or claim 8, wherein the interface between the supervisory control system and the multi-pool storage control system can be implemented through adjustment of the upstream supply flow alone, enabling the multipool storage control system to automatically coordinate pool levels in response to the resulting supply-demand mismatch without requiring direct communication of individual pool set-points or complex control calculations.

10. The water distribution system of any one of claims 7 to 9, wherein the supervisory control system interfaces with a demand management system to implement demand rescheduling when the multi-pool storage control system indicates that maintaining hydraulic constraints requires temporary service modifications, with the extended time buffer provided by multi-pool coordination enabling negotiated demand adjustments rather than emergency curtailments.

11. The water distribution system of any one of the preceding claims, wherein selected pools from said plurality of pools can include delivery of water from a connected respective supplementary off- stream auxiliary water storage, and wherein said supplementary off- stream water storage can be controlled to provide supplementary water to its selected pool or provide all the water to said selected pool, and wherein said supplementary off-stream water storage may receive water from a selected pool for storage.

12. The water distribution system of any one of the preceding claims, wherein said channel includes regulated gravity-fed open regulated waterways such as irrigation channels, rivers, streams, or stormwater management systems.

13. The water distribution system of any one of the preceding claims, wherein said multi-pool storage control system is configured to manage storm water surge events by coordinating available storage capacity across multiple pools to buffer unmeasured and unpredictable storm water inflows, preventing overtopping and infrastructure damage while minimizing uncontrolled releases to environmental receiving waters.

14. A water distribution system for controlling the delivery of water under gravity to at least one customer through a computer- controlled channel, said channel having a plurality of pools which are open conduits between respective upstream and downstream regulators and have both a hydraulic capacity and defined channel bank or maximum allowable operating level; one of said pools having at least one lateral offtake to provide said delivery of water to said at least one customer; said water distribution system having a multi-pool storage control system that reactively provides flow commands to control the opening of the regulators; said multi-pool storage control system determines the flow commands to utilize the distributed storage along sections of channel in a balanced way to compensate for the lack of full controllability of the supply and demand at the ends.

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