- Email: [email protected]
Water Distribution System of Santa Marta city, Colombia
Available online at www.sciencedirect.com
ScienceDirect Procedia Engineering 186 (2017) 20 – 27
XVIII International Conference on Water Distribution Systems Analysis, WDSA2016
Water Distribution System of Santa Marta city, Colombia Luis Londoño1, Johana Segrera1, Margarita Jaramillo1* 1
METROAGUA S.A. E.S.P. Santa Marta, Magdalena, Colombia
Abstract
Santa Marta is a city on the Caribbean coast of Colombia, the water distribution system is operated by Metroagua S.A and has 91,4% coverage represented by 95,420 users. The natural sources of water supply are Piedras, Manzanares and Gaira Rivers and the aquifer of Santa Marta, water is transported to the two water treatment plants: Mamatoco and El Roble. It has a Non-revenue water index of 46.8% mainly due fraudulent connections. On the other hand, the water distribution network is divided into two major subsystems: Subsystem North formed by 19 sectors and Subsystem South with 6. The main problem of the city is the water shortage due the severe drought, which has led to propose solutions to short, medium and long terms. 2016Published The Authors. Published by Elsevier ©©2016 by Elsevier Ltd. This is an openLtd. access article under the CC BY-NC-ND license Peer-review under responsibility of the organizing committee of the XVIII International Conference on Water Distribution (http://creativecommons.org/licenses/by-nc-nd/4.0/). Systems. under responsibility of the organizing committee of the XVIII International Conference on Water Distribution Systems Peer-review Keywords: Water Distribution System, water treatment, water supply
1. Description of the City Santa Marta is a city located over the Caribbean coast, northern of Colombia. Officially Tourist District, Cultural and Historical it is the capital of the department of Magdalena, is seated between the coast and Sierra Nevada de Santa Marta foothills, a peripheral mountainous massif and mean hydric source in the region for its top glaciers and moors. Is the oldest city existing in Colombia and the second oldest in South America. This city is bordered to the north and west by the Caribbean Sea, south with the municipalities of Ciénaga and Aracataca and east with the department of La Guajira through the Palomino river. The topography of the city is relatively flat, with surrounding. The city is
* Corresponding author. Tel.: +0-000-000-0000 ; fax: +0-000-000-0000 . E-mail address: [email protected]
1877-7058 © 2016 Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license
(http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of the organizing committee of the XVIII International Conference on Water Distribution Systems
doi:10.1016/j.proeng.2017.03.203
21
Luis Londoño et al. / Procedia Engineering 186 (2017) 20 – 27
crossed by Manzanares and Gaira Rivers that begin in the mountainous massif mentioned before [1]. The city has an important coastal aquifer recharge by Manzanares and Gaira Rivers and the Tamacá brook [2]. It presents a tropical climate as well, with average annual temperatures of 23 °C to 32 °C [1]. Its average precipitation does not exceed 362 mm of rain per year. Its main economic activities are commerce and tourism; among the tourist sites are emblematic Rodadero, Taganga, Tayrona National Natural Park, Minca and Ciudad Perdida. Nowadays, it has an estimated population of 500 thousand inhabitants in constant growth, this excluding floating population[2]. 2. Description of supplied population Nowadays, Santa Marta’s water distribution system is operated by METROAGUA S.A. E.S.P. and has a coverage of 91,4% represented by 95420 users. The Table 1classifies the users of the city [3]. Table 1. Type of Users connected to the water distribution system of Santa Marta Type of Users Residential Commercial Industrial Total
Number of Users
Coverage
89,886 5,429 105 95,420
94.20% 5.69% 0.11% 100%
As it could be seen in Fig. 1, commercial users are concentrated mostly in two specific zones inside the city, Centro Histórico (ancient city downtown) and the touristic neighborhood known as "El Rodadero", besides, they concentrate along main avenues. Industrial users are located heterogeneously distributed, while residential users surround the Centro Histórico, representing most of the population users. In the present, serviced population represents a total flow demand of 1220 L/s in the source, estimated as average daily flow, with a per-capita endowment of 150 Liters per habitant per day [3].
Fig. 1. Spatial distribution of the types of users of Santa Marta
3. Description of the Water Distribution System 3.1. Supplying Sources Supplying systems of the city’s water distribution system are Manzanares, Piedras and Gaira rivers and the Santa Marta aquifer. In the case of the mentioned rivers, they are born in Sierra Nevada de Santa Marta (Santa Marta snowy massif), specifically on the San Lorenzo basin to an approximate height of 2600 meters above sea level and flows into
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Luis Londoño et al. / Procedia Engineering 186 (2017) 20 – 27
the Caribbean Sea going across the city. The water catchment takes place in the middle part of the basin of these rivers: transporting by adduction pipes to the treatment plant (TP) Mamatoco for the case of Piedras and Manzanares Rivers and TP El Roble in the case of Gaira River. Likewise, the water distribution system of the city has a battery from deep wells that collect water from the aquifer of Santa Marta [3]. Under normal operating conditions are 18 deep wells, 14 are located in the northern region and 4 in the south. These wells supply over 50% of the city, especially in summer times providing a flow of 300 L/s to the system [. The Fig. 2 describe this.
Fig. 2. (a) Supply potable water of Santa Marta City; (b) Supplying systems of Santa Marta
3.2. Treatment plant The Treated flows in the TP Mamatoco and TP El Roble differ significantly between summer and winter seasons. During the winter city, the TP Mamatoco is able to treat from t Manzanares and Piedras Rivers see Table 2. During the summer, the same TP is used only for Piedras River, while for the case of treatment of the waters of the Manzanares River; the situation is exacerbated because the TP practically does not get water from this river because illegal connections that currently exist along the intake pipe [3]. In the case of the TP El Roble, flow available varies depending on the winter or summer, see Table 3. Table 2. Water treatment from the Manzanares and Piedras rivers in the PTP Mamatoco. Treatment plant Mamatoco Treated Effluent Treated flow in Treated flow in Summer Winter Río Manzanares 0 400 L/s Río Piedras 150 L/s 400 L/s Purification tratment plant Mamatoco Table 3. Water treatment from the Gaira river in the PTP El Roble. Treatment plant El Roble Treated Effluent Treated flow in Summer Río Gaira 150 L/s Purification tratment plant El Roble
Caudal tratado en Winter 450 L/s
Luis Londoño et al. / Procedia Engineering 186 (2017) 20 – 27
As regards water quality of these superficial sources, it is possible to say they are in good conditions. For the cases of Piedras and Manzanares rivers, turbidity average values arriving to the Mamatoco plant are about 2.0 NTU, while pH presents an average value of 7.67. As regards Gaira river, average turbidity is about 42 NTU and the average pH is 7,85 [3]. 3.3. Parent network and Distribution network In reference to the distribution system, this is divided into two big sub-systems. The first one, called North, is supplied by the Mamatoco plant and 14 deep wells constructed in this zone. At the same time, the second sub-system, called South and includes the touristic neighborhood “El Rodadero”, Gaira and the touristic corridor, located southern of the city, is supplied by El Roble plant and 4 deep wells constructed in the zone [3]. Figure 3 (b) illustrates both subsystems. The parent network and distribution consist of approximately 929 km of pipes made of diverse materials such as cast iron, carbon steel, ductile iron, asbestos-cement, PVC, PEAD, CCP and GRP with diameters between 3’’ and 36’’. It has 26 storage tanks that sums 28800 m3. The system is a gravity –fed one and works from the catchments, nevertheless, it requires a series of pumping stations to rise energy (25 Potable Water Pumping Stations) in the distribution network due to disordered city growth towards mountains. Fig. 4. Shows the parent network for both subsystems, leftward it is possible to observe North sub-system and rightward, South sub-system.
Fig. 3. Matrix North and South Subsystem.
3.3.1 Sectorization The distribution network of the North System is composed of 19 sectors and the South System by 6 sectors, for a total of 25 sectors [3]. The number of sectors has been gradually increasing, from open loop system complex in their control to a network which can make more efficient flow control and improve the operating pressures in each network. In Fig. 4 shows the segmentation of each of the systems. To the left is the sectorization for the North and the right is the sectorization South system.
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Luis Londoño et al. / Procedia Engineering 186 (2017) 20 – 27
Fig. 4. Sectorization of North (left) and South subsystems (right)
Even though the improvement mentioned before with the land demarcation process, the system handles a pressure range between 1,5 meters of water column (mwc) and 7 mwc. This due to operation conditions of the system, these being very singular because most houses have deposits to storage water due to offer deficits that prevents a normal network pressurization and a non-existent stable behavior patron of daily demand [3]. 3.3.2 Distribution Network Modelling The Distribution Network counts with an Epanet model, which was developed together with Universidad de Los Andes (Colombia). The friction losses equation used for hydraulics modelling was Darcy-Weisbach, with an extended running period for modeling of 48 hours with an interval of hydraulic calculation of 5 minutes [2]. This is a useful tool that allows to know the real-time state of the system taking into account present conditions and, similarly, to predict the city’s future behavior due to ideal or non-ideal future conditions. The model counts with a total of 10423 nodes, 13211 pipes, 19 tanks and 52 pumping stations [2]. 4. Problems Presented and Proposed Solutions During the last years, Santa Marta has faced an intense season of drought, which have affected considerably that river flows that supplies water services, to the point to take an emergency state in the city [4] (Fig. 5). As seen in the figure, the decline in flows in rivers that supply potable water to the city every year is dramatic, falling even below 1.00 m3/ s for most of 2015. The Table 4 shows, for winter conditions and summer, the current and future deficits presented in the offer, taking into account the demand calculated by the study at the University of the Andes. In terms of MFD (Maximum Flow Daily) for the urban area of Santa Marta, Taganga and Bonda townships and the floating population that occurs mainly in high tourist season. In addition to the severe drought and the vulnerability of current sources to global climate change, other factors like rapid population growth (as a result of the social phenomenon of movement of people from rural areas to urban centers like Santa Marta) and lack of urban planning and urban control also affect the current supply deficit. With regard to the latter two points, nowadays, were have been detected by METROAGUA S.A. E.S.P. more than 21,600 fraudulent connections, which largely represent trading losses that make the Non-revenue water index is 46.8% [3].
25
Luis Londoño et al. / Procedia Engineering 186 (2017) 20 – 27 COMPORTAMIENTO CAUDALES RÍOS DE ABASTECIMIENTO DE SANTA MARTA Año 2012
Año 2013
Año 2014
Año 2015
Año 2016
10.00 9.00 8.00
m3/s
7.00 6.00 5.00 4.00 3.00 2.00
1.00 DICIEMBRE
NOVIEMBRE
OCTUBRE
SEPTIEMBRE
AGOSTO
JULIO
JUNIO
MAYO
ABRIL
MARZO
FEBRERO
ENERO
0.00
Fig. 5. Behavior of the sum of flows rivers that supply the city of Santa Marta [5]. Table 4. Current and future deficit supply at the source [2]. 2016 2064 Demand 2.477 L/s 6.121 L/s Offer Winter Summer Winter Summer 1. PTP Mamatoco 800 L/s 150 lps 800 lps 150 lps 2. PTP Roble 450 L/s 150 lps 450 lps 150 lps 3. Deep wells 300 L/s 600 lps 300 lps 600 lps Deficit -927 L/s -1.577 L/s -4.571 L/s -5.221 L/s
Now, as a solution to the previous problem, METROAGUA S.A. E.S.P. has managed a series of short, medium and long term actions are described below. The actions are not isolated but are harmonious with each other, especially those in the short term to mitigate the supply deficit while the final solution (the medium and long term) is implemented. 4.1 Extending battery of deep wells Among the actions undertaken in the short term are drilling and commissioning of 32 new deep wells in addition to the 18 existing is, whose production has gradually injecting the distribution network across the city to strengthen the service of potable water in critical areas where dramatically lowered surface water flows in dry seasons. These wells will contribute to the system an estimated total of 600 liters per second. To preserve the aquifer, these wells are put into work according to the supplying needs and according to the superficial sources behavior.
Fig. 6. Localization of construction and exploitation deep wells of Santa Marta’s aquifer as a short-term solution (left). Distribution Network classificaton according to its asociated risk of supply shortages. (Right)
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Luis Londoño et al. / Procedia Engineering 186 (2017) 20 – 27
4.2 Risk management Matrix of supply shortages METROAGUA S.A. E.S.P. has stablished a risk management matrix for drought seasons in Santa Marta, allowing to print a clear radiography of service conditions and sectors with more supply shortages risks due to possible droughts scenarios. In this way, it is possible to make new organized actions for optimizing use resources, which the company have and stablish improvements in the water distribution service offer, anticipating needs in extreme drought conditions [5]. 4.3 Micro-sectorization In order that all users have access to potable water with the supply flow available, METROAGUA S.A. E.S.P. has divided the network into 58 micro-sectors that distribute water through operational shift established service. This improve the pressures, reduce filling times of the network and control the use of resources by the population supplied [3].
Fig. 7. Micro-sectorization of subsystems North (left) and South (right).
4.4 Final solution The "Study for strengthening the health infrastructure in Santa Marta for the requirements projected in the next 50 years" by the University of the Andes in 2015 determined that the use of the Magdalena, Toribio and Cordoba Rivers as additional sources to current, are the final solution supply. To reach this solution were studied alternatives that included the use of the rivers of the northeast and north side of the Sierra Nevada de Santa Marta and desalination of sea. The analysis and selection criteria took into account technical, economic, environmental, political, social and anthropological aspects, which were evaluated by a matrix of multi-attribute utility [2]. The criteria analyzed were: Analyze the speed to breakeven alternative, analyze the speed input of the first stage of the alternative, analyze system reliability, assessing the costs of implementing the alternative in terms of construction, evaluate the feasibility of alternatives from the point of view of the natives problems, assess the feasibility of alternatives from the point of view of invasion of National Parks, assess the feasibility of the alternatives considering sacred sites for the native population, determine the ease of operation of the alternative, evaluate the possibility of future expansion, minimize the environmental impact that can generate the alternative, maximize attributed to the implementation of alternative social benefits, assessing vulnerability to climate change, vulnerability assessment system, evaluating the stage where water losses adducted you have, assess the cost per cubic meter of treated water and power cost required in adduction. The following chart shows the analysis of supply and demand made in the study for the next 50 years to drought conditions and demand including the floating population.
Luis Londoño et al. / Procedia Engineering 186 (2017) 20 – 27
Fig. 8. Offer and demand including final solution [2].
The final solution consists in capturing water from the three rivers mentioned before an treat it in a new treatment plant that would be located near the municipality of Ciénaga, neighboring Santa Marta, which would allow water entering the system by pumping from the south of the city. Additionally, it is contemplated the construction of 3 big storage tanks located over Santa Marta’s perimeter mountains in a height that guarantees adequate pressures and will supply the city by a 100% gravity-fed system. This solution would be complemented with the utilization of Piedras River through a new plant, located in the northeastern sector in a height of 200 meters above the sea (approximate) which will supply higher zones in the city. For the year 2064, the research horizon, it is projected to capture between all sources 6121 liters per second for a population stimated of 2’101500 including floating population [2].
Fig. 9. Definitive Solution: Use of Magdalena, Toribio and Magdalena Rivers
References [1] Alcaldía de Santa Marta, Distrito Turístico, cultural e Histórico. (2016) http://www.santamarta.gov.co/portal/ [2] Universidad de los andes. (2014). Estudio para el fortalecimiento de la infraestructura sanitaria de Santa Marta para los requerimientos proyectados en los próximos 50 años. [3] METROAGUA S.A E.S.P (2016) Empresa de servicios públicos, perteneciente al grupo Inassa www.metroagua.com.co [4] Decreto No. 043 del 27 de Marzo de 2014. Declaratoria de calamidad pública en Santa Marta D.T.C.H [5] METROAGUA S.A E.S.P (2015). Matriz de la gestión del riesgo, para los periodos de sequía en Santa Marta. Empresa de servicios públicos, perteneciente al grupo Inassa. www.metroagua.com.co
27
ScienceDirect Procedia Engineering 186 (2017) 20 – 27
XVIII International Conference on Water Distribution Systems Analysis, WDSA2016
Water Distribution System of Santa Marta city, Colombia Luis Londoño1, Johana Segrera1, Margarita Jaramillo1* 1
METROAGUA S.A. E.S.P. Santa Marta, Magdalena, Colombia
Abstract
Santa Marta is a city on the Caribbean coast of Colombia, the water distribution system is operated by Metroagua S.A and has 91,4% coverage represented by 95,420 users. The natural sources of water supply are Piedras, Manzanares and Gaira Rivers and the aquifer of Santa Marta, water is transported to the two water treatment plants: Mamatoco and El Roble. It has a Non-revenue water index of 46.8% mainly due fraudulent connections. On the other hand, the water distribution network is divided into two major subsystems: Subsystem North formed by 19 sectors and Subsystem South with 6. The main problem of the city is the water shortage due the severe drought, which has led to propose solutions to short, medium and long terms. 2016Published The Authors. Published by Elsevier ©©2016 by Elsevier Ltd. This is an openLtd. access article under the CC BY-NC-ND license Peer-review under responsibility of the organizing committee of the XVIII International Conference on Water Distribution (http://creativecommons.org/licenses/by-nc-nd/4.0/). Systems. under responsibility of the organizing committee of the XVIII International Conference on Water Distribution Systems Peer-review Keywords: Water Distribution System, water treatment, water supply
1. Description of the City Santa Marta is a city located over the Caribbean coast, northern of Colombia. Officially Tourist District, Cultural and Historical it is the capital of the department of Magdalena, is seated between the coast and Sierra Nevada de Santa Marta foothills, a peripheral mountainous massif and mean hydric source in the region for its top glaciers and moors. Is the oldest city existing in Colombia and the second oldest in South America. This city is bordered to the north and west by the Caribbean Sea, south with the municipalities of Ciénaga and Aracataca and east with the department of La Guajira through the Palomino river. The topography of the city is relatively flat, with surrounding. The city is
* Corresponding author. Tel.: +0-000-000-0000 ; fax: +0-000-000-0000 . E-mail address: [email protected]
1877-7058 © 2016 Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license
(http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of the organizing committee of the XVIII International Conference on Water Distribution Systems
doi:10.1016/j.proeng.2017.03.203
21
Luis Londoño et al. / Procedia Engineering 186 (2017) 20 – 27
crossed by Manzanares and Gaira Rivers that begin in the mountainous massif mentioned before [1]. The city has an important coastal aquifer recharge by Manzanares and Gaira Rivers and the Tamacá brook [2]. It presents a tropical climate as well, with average annual temperatures of 23 °C to 32 °C [1]. Its average precipitation does not exceed 362 mm of rain per year. Its main economic activities are commerce and tourism; among the tourist sites are emblematic Rodadero, Taganga, Tayrona National Natural Park, Minca and Ciudad Perdida. Nowadays, it has an estimated population of 500 thousand inhabitants in constant growth, this excluding floating population[2]. 2. Description of supplied population Nowadays, Santa Marta’s water distribution system is operated by METROAGUA S.A. E.S.P. and has a coverage of 91,4% represented by 95420 users. The Table 1classifies the users of the city [3]. Table 1. Type of Users connected to the water distribution system of Santa Marta Type of Users Residential Commercial Industrial Total
Number of Users
Coverage
89,886 5,429 105 95,420
94.20% 5.69% 0.11% 100%
As it could be seen in Fig. 1, commercial users are concentrated mostly in two specific zones inside the city, Centro Histórico (ancient city downtown) and the touristic neighborhood known as "El Rodadero", besides, they concentrate along main avenues. Industrial users are located heterogeneously distributed, while residential users surround the Centro Histórico, representing most of the population users. In the present, serviced population represents a total flow demand of 1220 L/s in the source, estimated as average daily flow, with a per-capita endowment of 150 Liters per habitant per day [3].
Fig. 1. Spatial distribution of the types of users of Santa Marta
3. Description of the Water Distribution System 3.1. Supplying Sources Supplying systems of the city’s water distribution system are Manzanares, Piedras and Gaira rivers and the Santa Marta aquifer. In the case of the mentioned rivers, they are born in Sierra Nevada de Santa Marta (Santa Marta snowy massif), specifically on the San Lorenzo basin to an approximate height of 2600 meters above sea level and flows into
22
Luis Londoño et al. / Procedia Engineering 186 (2017) 20 – 27
the Caribbean Sea going across the city. The water catchment takes place in the middle part of the basin of these rivers: transporting by adduction pipes to the treatment plant (TP) Mamatoco for the case of Piedras and Manzanares Rivers and TP El Roble in the case of Gaira River. Likewise, the water distribution system of the city has a battery from deep wells that collect water from the aquifer of Santa Marta [3]. Under normal operating conditions are 18 deep wells, 14 are located in the northern region and 4 in the south. These wells supply over 50% of the city, especially in summer times providing a flow of 300 L/s to the system [. The Fig. 2 describe this.
Fig. 2. (a) Supply potable water of Santa Marta City; (b) Supplying systems of Santa Marta
3.2. Treatment plant The Treated flows in the TP Mamatoco and TP El Roble differ significantly between summer and winter seasons. During the winter city, the TP Mamatoco is able to treat from t Manzanares and Piedras Rivers see Table 2. During the summer, the same TP is used only for Piedras River, while for the case of treatment of the waters of the Manzanares River; the situation is exacerbated because the TP practically does not get water from this river because illegal connections that currently exist along the intake pipe [3]. In the case of the TP El Roble, flow available varies depending on the winter or summer, see Table 3. Table 2. Water treatment from the Manzanares and Piedras rivers in the PTP Mamatoco. Treatment plant Mamatoco Treated Effluent Treated flow in Treated flow in Summer Winter Río Manzanares 0 400 L/s Río Piedras 150 L/s 400 L/s Purification tratment plant Mamatoco Table 3. Water treatment from the Gaira river in the PTP El Roble. Treatment plant El Roble Treated Effluent Treated flow in Summer Río Gaira 150 L/s Purification tratment plant El Roble
Caudal tratado en Winter 450 L/s
Luis Londoño et al. / Procedia Engineering 186 (2017) 20 – 27
As regards water quality of these superficial sources, it is possible to say they are in good conditions. For the cases of Piedras and Manzanares rivers, turbidity average values arriving to the Mamatoco plant are about 2.0 NTU, while pH presents an average value of 7.67. As regards Gaira river, average turbidity is about 42 NTU and the average pH is 7,85 [3]. 3.3. Parent network and Distribution network In reference to the distribution system, this is divided into two big sub-systems. The first one, called North, is supplied by the Mamatoco plant and 14 deep wells constructed in this zone. At the same time, the second sub-system, called South and includes the touristic neighborhood “El Rodadero”, Gaira and the touristic corridor, located southern of the city, is supplied by El Roble plant and 4 deep wells constructed in the zone [3]. Figure 3 (b) illustrates both subsystems. The parent network and distribution consist of approximately 929 km of pipes made of diverse materials such as cast iron, carbon steel, ductile iron, asbestos-cement, PVC, PEAD, CCP and GRP with diameters between 3’’ and 36’’. It has 26 storage tanks that sums 28800 m3. The system is a gravity –fed one and works from the catchments, nevertheless, it requires a series of pumping stations to rise energy (25 Potable Water Pumping Stations) in the distribution network due to disordered city growth towards mountains. Fig. 4. Shows the parent network for both subsystems, leftward it is possible to observe North sub-system and rightward, South sub-system.
Fig. 3. Matrix North and South Subsystem.
3.3.1 Sectorization The distribution network of the North System is composed of 19 sectors and the South System by 6 sectors, for a total of 25 sectors [3]. The number of sectors has been gradually increasing, from open loop system complex in their control to a network which can make more efficient flow control and improve the operating pressures in each network. In Fig. 4 shows the segmentation of each of the systems. To the left is the sectorization for the North and the right is the sectorization South system.
23
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Luis Londoño et al. / Procedia Engineering 186 (2017) 20 – 27
Fig. 4. Sectorization of North (left) and South subsystems (right)
Even though the improvement mentioned before with the land demarcation process, the system handles a pressure range between 1,5 meters of water column (mwc) and 7 mwc. This due to operation conditions of the system, these being very singular because most houses have deposits to storage water due to offer deficits that prevents a normal network pressurization and a non-existent stable behavior patron of daily demand [3]. 3.3.2 Distribution Network Modelling The Distribution Network counts with an Epanet model, which was developed together with Universidad de Los Andes (Colombia). The friction losses equation used for hydraulics modelling was Darcy-Weisbach, with an extended running period for modeling of 48 hours with an interval of hydraulic calculation of 5 minutes [2]. This is a useful tool that allows to know the real-time state of the system taking into account present conditions and, similarly, to predict the city’s future behavior due to ideal or non-ideal future conditions. The model counts with a total of 10423 nodes, 13211 pipes, 19 tanks and 52 pumping stations [2]. 4. Problems Presented and Proposed Solutions During the last years, Santa Marta has faced an intense season of drought, which have affected considerably that river flows that supplies water services, to the point to take an emergency state in the city [4] (Fig. 5). As seen in the figure, the decline in flows in rivers that supply potable water to the city every year is dramatic, falling even below 1.00 m3/ s for most of 2015. The Table 4 shows, for winter conditions and summer, the current and future deficits presented in the offer, taking into account the demand calculated by the study at the University of the Andes. In terms of MFD (Maximum Flow Daily) for the urban area of Santa Marta, Taganga and Bonda townships and the floating population that occurs mainly in high tourist season. In addition to the severe drought and the vulnerability of current sources to global climate change, other factors like rapid population growth (as a result of the social phenomenon of movement of people from rural areas to urban centers like Santa Marta) and lack of urban planning and urban control also affect the current supply deficit. With regard to the latter two points, nowadays, were have been detected by METROAGUA S.A. E.S.P. more than 21,600 fraudulent connections, which largely represent trading losses that make the Non-revenue water index is 46.8% [3].
25
Luis Londoño et al. / Procedia Engineering 186 (2017) 20 – 27 COMPORTAMIENTO CAUDALES RÍOS DE ABASTECIMIENTO DE SANTA MARTA Año 2012
Año 2013
Año 2014
Año 2015
Año 2016
10.00 9.00 8.00
m3/s
7.00 6.00 5.00 4.00 3.00 2.00
1.00 DICIEMBRE
NOVIEMBRE
OCTUBRE
SEPTIEMBRE
AGOSTO
JULIO
JUNIO
MAYO
ABRIL
MARZO
FEBRERO
ENERO
0.00
Fig. 5. Behavior of the sum of flows rivers that supply the city of Santa Marta [5]. Table 4. Current and future deficit supply at the source [2]. 2016 2064 Demand 2.477 L/s 6.121 L/s Offer Winter Summer Winter Summer 1. PTP Mamatoco 800 L/s 150 lps 800 lps 150 lps 2. PTP Roble 450 L/s 150 lps 450 lps 150 lps 3. Deep wells 300 L/s 600 lps 300 lps 600 lps Deficit -927 L/s -1.577 L/s -4.571 L/s -5.221 L/s
Now, as a solution to the previous problem, METROAGUA S.A. E.S.P. has managed a series of short, medium and long term actions are described below. The actions are not isolated but are harmonious with each other, especially those in the short term to mitigate the supply deficit while the final solution (the medium and long term) is implemented. 4.1 Extending battery of deep wells Among the actions undertaken in the short term are drilling and commissioning of 32 new deep wells in addition to the 18 existing is, whose production has gradually injecting the distribution network across the city to strengthen the service of potable water in critical areas where dramatically lowered surface water flows in dry seasons. These wells will contribute to the system an estimated total of 600 liters per second. To preserve the aquifer, these wells are put into work according to the supplying needs and according to the superficial sources behavior.
Fig. 6. Localization of construction and exploitation deep wells of Santa Marta’s aquifer as a short-term solution (left). Distribution Network classificaton according to its asociated risk of supply shortages. (Right)
26
Luis Londoño et al. / Procedia Engineering 186 (2017) 20 – 27
4.2 Risk management Matrix of supply shortages METROAGUA S.A. E.S.P. has stablished a risk management matrix for drought seasons in Santa Marta, allowing to print a clear radiography of service conditions and sectors with more supply shortages risks due to possible droughts scenarios. In this way, it is possible to make new organized actions for optimizing use resources, which the company have and stablish improvements in the water distribution service offer, anticipating needs in extreme drought conditions [5]. 4.3 Micro-sectorization In order that all users have access to potable water with the supply flow available, METROAGUA S.A. E.S.P. has divided the network into 58 micro-sectors that distribute water through operational shift established service. This improve the pressures, reduce filling times of the network and control the use of resources by the population supplied [3].
Fig. 7. Micro-sectorization of subsystems North (left) and South (right).
4.4 Final solution The "Study for strengthening the health infrastructure in Santa Marta for the requirements projected in the next 50 years" by the University of the Andes in 2015 determined that the use of the Magdalena, Toribio and Cordoba Rivers as additional sources to current, are the final solution supply. To reach this solution were studied alternatives that included the use of the rivers of the northeast and north side of the Sierra Nevada de Santa Marta and desalination of sea. The analysis and selection criteria took into account technical, economic, environmental, political, social and anthropological aspects, which were evaluated by a matrix of multi-attribute utility [2]. The criteria analyzed were: Analyze the speed to breakeven alternative, analyze the speed input of the first stage of the alternative, analyze system reliability, assessing the costs of implementing the alternative in terms of construction, evaluate the feasibility of alternatives from the point of view of the natives problems, assess the feasibility of alternatives from the point of view of invasion of National Parks, assess the feasibility of the alternatives considering sacred sites for the native population, determine the ease of operation of the alternative, evaluate the possibility of future expansion, minimize the environmental impact that can generate the alternative, maximize attributed to the implementation of alternative social benefits, assessing vulnerability to climate change, vulnerability assessment system, evaluating the stage where water losses adducted you have, assess the cost per cubic meter of treated water and power cost required in adduction. The following chart shows the analysis of supply and demand made in the study for the next 50 years to drought conditions and demand including the floating population.
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Fig. 8. Offer and demand including final solution [2].
The final solution consists in capturing water from the three rivers mentioned before an treat it in a new treatment plant that would be located near the municipality of Ciénaga, neighboring Santa Marta, which would allow water entering the system by pumping from the south of the city. Additionally, it is contemplated the construction of 3 big storage tanks located over Santa Marta’s perimeter mountains in a height that guarantees adequate pressures and will supply the city by a 100% gravity-fed system. This solution would be complemented with the utilization of Piedras River through a new plant, located in the northeastern sector in a height of 200 meters above the sea (approximate) which will supply higher zones in the city. For the year 2064, the research horizon, it is projected to capture between all sources 6121 liters per second for a population stimated of 2’101500 including floating population [2].
Fig. 9. Definitive Solution: Use of Magdalena, Toribio and Magdalena Rivers
References [1] Alcaldía de Santa Marta, Distrito Turístico, cultural e Histórico. (2016) http://www.santamarta.gov.co/portal/ [2] Universidad de los andes. (2014). Estudio para el fortalecimiento de la infraestructura sanitaria de Santa Marta para los requerimientos proyectados en los próximos 50 años. [3] METROAGUA S.A E.S.P (2016) Empresa de servicios públicos, perteneciente al grupo Inassa www.metroagua.com.co [4] Decreto No. 043 del 27 de Marzo de 2014. Declaratoria de calamidad pública en Santa Marta D.T.C.H [5] METROAGUA S.A E.S.P (2015). Matriz de la gestión del riesgo, para los periodos de sequía en Santa Marta. Empresa de servicios públicos, perteneciente al grupo Inassa. www.metroagua.com.co
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