HAARLEM HYDRAULICS & TECHNICAL UNIVERSITY OF DELFT Sedawgyi Water Resources/Irrigation system simulations A study into the water resources and flood risk of Mandalay basin with RIBASIM Sebastiaan Quirijns 1387272 11/14/2014 Supervisors TU First: Nick van der Giesen TU Second: Martine Rutten Company: Peter Kerssens Haarlem Hydraulics A study performed by Sebastiaan Quirijns in order to accomplish his internship at Haarlem Hydraulics for the Technical University of Delft.
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HAARLEM HYDRAULICS & TECHNICAL UNIVERSITY OF DELFT
Sedawgyi Water Resources/Irrigation system simulations
A study into the water resources and flood risk of Mandalay basin with RIBASIM
Sebastiaan Quirijns
1387272
11/14/2014
Supervisors
TU First: Nick van der Giesen
TU Second: Martine Rutten
Company: Peter Kerssens
Haarlem Hydraulics
A study performed by Sebastiaan Quirijns in order to accomplish his internship at Haarlem Hydraulics for the Technical University of Delft.
Internship Report by Sebastiaan Quirijns Sedawgyi Water Resources/Irrigation system simulations
Haarlem Hydraulics & Technical University of Delft | Summary 1
Thank you all
For helping me by sharing your knowledge,
guidance and resources.
For giving me this amazing experience
Peter J.M. Kerssens
Gary Moys
Wil van der Krogt
Uu Tin Oo
Htet Wint Naing
PM- Group
Safege
MMiC
Mandalay City Development Committee
Irrigation Department, Mandalay (and Main Office)
Asian Development Bank
Agence Française de Développement
Technical University of Delft
Deltares
E.A.
Summary During three months a study has been done by Sebastiaan Quirijns into the modelling of
the water resources of the Sedawgyi Irrigation Network. In this study the feasibility of multiple
scenarios have been modelled regarding the water resources system efficiency. The modelling of
this basin has been executed with RIBASIM (River Basin Simulation Model). A modelling
program made by ‘Deltares’. The setup of the study is done by the ASSECR-method, in
chronological order this is analyses, synthesis, simulation, evaluation and last is conclusions and
recommendations.
The current situation in the Sedawgyi basin is the low efficiency of the water usage in the
water resources system. During the rainy season lots of water gets released to avoid spillage.
Not all this released water can be used in the agricultural areas, so the water flows towards
Mandalay and causes serious floods in the city. On the other hand the during the drought periods
the water is accumulated in the basin and there is not enough water for all the demand. Another
issue in the area is the flood risk caused by the Shan Hills to the east of Mandalay. Precipitation
in the catchment area flows towards Mandalay city and causes floods eastern parts of Mandalay.
Scenarios are based upon actual ideas or designs by ‘ADB PPTA’ and ‘M.C.D.C.’. Although
the ‘ADB PPTA’ is already in a further stage, the modelling results are needed to give support to
the decisions made by ‘ADB PPTA’.
The scenarios are the:
1. ‘Base Case’; In this case the current situation is shown.
2. ‘Do Nothing Case’; This case is similar to the ‘Base Case’, but it is now including long term
effects and visualizes the issues if nothing is done in 2040.
3. ‘ADB Reference Case’; Here all future plans of ‘ADB PPTA’ are included in the model for
2040.
4. ‘SUDS scenario’; Increasing the return flow to the surface water and reduce flood risk in
the city in 2040, in order to increase quality of life in Mandalay.
5. ‘Capacity Training Agriculture scenario’; By increasing the irrigation efficiency a higher
production yield can be achieved with less supply.
6. ‘Secondary Open Channel’; The purpose of this secondary channel is to reduce flood risk
by rainfall in the Shan Hills. The water is than redirected as a new inflow into the
Sedawgyi water resources system.
7. ‘Separation of water resources system’; By dividing the water resources for public water
supply for Mandalay and irrigational purposes more water is available for irrigation
coming from Sedawgyi dam.
After the simulations it was clear that in the ‘Do Nothing Case’ in 2040 some sincere
issues were raised in water availability for both PWS and irrigation. The climate change effects
and other long term autonomous effects which were included in the 2040 models, seriously
reduce the total water availability by the Sedawgyi Reservoir. For all the other scenarios the
results were evident that it is not possible with the current operational settings to combine PWS
and irrigation. This is in line with the expectations of ‘ADP PPTA’. In order to raise total water
usage efficiency the water resources system has to be separated and combined with increased
irrigation efficiency.
For achieving this modelling results in real life ,’ M.C.D.C’ is advised to construct a separate
system for PWS, such as water treatment plans and retention ponds. Also increase the capacity
Internship Report by Sebastiaan Quirijns Sedawgyi Water Resources/Irrigation system simulations
Haarlem Hydraulics & Technical University of Delft | Summary 3
of the farmers to achieve higher production yields. This can be done by investing in new
methods and material for the farmers, who now still apply old fashioned methods for irrigation.
List of abbreviations Abbreviation Description ADB Asian Development Bank AFD Agence Francaise Developpement DNC Do Nothing Case ID Irrigation Department DY Distributaries ETo Relative Evapotranspiration MCDC Mandalay City Development Committee MMc Mandalay Main canal MUSIP Mandalay Urban Services Improvement
Project NRW Non Revenue Water PPTA Project Preparation Technical Assistance PWS Public Water Supply SIN Sedawgyi Irrigation Network SUDS Sustainable Urban Drainage System SUI Secondary Uncontrolled Inflow SWRS Splitting the Water Resources System SRWRS Sedawgyi Reservoir Water Resources System ts Time step WRS Water Resources System Table 1 List of abbreviations
Internship Report by Sebastiaan Quirijns Sedawgyi Water Resources/Irrigation system simulations
Haarlem Hydraulics & Technical University of Delft | List of conversions 5
List of conversions 1 inch [in] 0.0254 [m 1 foot [ft] 0.3048 m 1 meter [m] 39.37 inch [m] 1 meter [m] 3.28 feet [ft] 1 square foot [ft2] 0.0929 [m2] 1 acre 4046.86 [m2] 1 acre 0.404686 [ha] 1 square meter [m2] 10.76 square feet [ft2] 1 square meter [m2] 0.00024 acres 1 hectare [ha] 2.47 acre 1 square miles [sq-miles] 259 hectare [ha] 1 hectare [ha] 0.003861 square miles [sq-mil] Volume 1 cubic foot [ft3] 0.0283 m3 1 cubic meter [m3] 35.315 cubic feet [ft3] 1 acre feet 0.0012335 Mm3 1 acre feet 1233500 m3 1 m3 0.000811 Acre feet [Ac-ft] Flow 1 cubic feet per second (Cusec) 0.02832 cubic meter per second (m3/s)
List of abbreviations ......................................................................................................................................................... 4
List of conversions ............................................................................................................................................................. 5
1.2 My objective ................................................................................................................................................... 10
1.3 Scope of the project .................................................................................................................................... 10
1.4 Set up of the study ....................................................................................................................................... 12
1.5 Notes for reading the report ................................................................................................................... 12
1.5.1 Personal Notes .................................................................................................................................... 12
1.5.2 Files on Appendix CD ........................................................................................................................ 13
2 Initial Analysis of the project area .................................................................................................................. 14
2.1 Project Area: Mandalay region ............................................................................................................... 14
2.1.1 Mandalay and Sedawgyi Irrigation Network area ................................................................ 14
2.2 Water Resources .......................................................................................................................................... 24
2.2.3 Sedawgyi Irrigation area ................................................................................................................. 29
2.3 Civil objects and canals ............................................................................................................................. 30
2.3.1 Sedawgyi Dam ..................................................................................................................................... 30
2.4 Data Analysis ................................................................................................................................................. 31
2.4.1 Data gaps ............................................................................................................................................... 31
2.4.2 Flawed Data .......................................................................................................................................... 31
2.4.3 Summary of causes of the errors ................................................................................................. 32
2.4.4 Small conclusion about data errors ............................................................................................ 32
2.5 Green Cities .................................................................................................................................................... 32
2.5.1 Relation to Mandalay/Sedawgyi Irrigation Network modelling .................................... 32
3 Introduction to RIBASIM .................................................................................................................................... 33
3.1 Basics of RIBASIM ........................................................................................................................................ 33
3.2 Applied model of the Sedawgyi Irrigation Network Model........................................................ 34
3.3 Definitive model ........................................................................................................................................... 34
Internship Report by Sebastiaan Quirijns Sedawgyi Water Resources/Irrigation system simulations
Haarlem Hydraulics & Technical University of Delft | List of conversions 7
4.1 Long term effects ......................................................................................................................................... 35
4.4 Constructing the scenarios ...................................................................................................................... 37
5 Simulations with RIBASIM ................................................................................................................................ 39
5.1 Base Case ......................................................................................................................................................... 39
5.1.1 Measured data ..................................................................................................................................... 39
5.2 Do Nothing Case ........................................................................................................................................... 41
5.3 ADB Reference Case .................................................................................................................................... 41
6.3 Net flow in water resources system ..................................................................................................... 45
6.4 Generation of hydropower ...................................................................................................................... 46
6.5 Actual cultivation areas ............................................................................................................................. 47
6.6 Supply/demand ratios for cultivations .............................................................................................. 48
7.1.4 Final Conclusion ................................................................................................................................. 55
12 List of figures ........................................................................................................................................................... 61
Internship Report by Sebastiaan Quirijns Sedawgyi Water Resources/Irrigation system simulations
Haarlem Hydraulics & Technical University of Delft | Introduction 9
1 Introduction On request of the Burmese government (Mandalay City Development Committee) a
project is performed in Mandalay in the context of the “Mandalay Urban Services Improvement
Project” (MUSIP). For this project a joint venture has been formed between two consultants PM-
group and Safege. The financing of the project is provided by the Asian Development Bank and
Agence Française de Développement. MMiC is a local sub-contractor who mostly assists by
providing local knowledge and connections in Myanmar as well as domestic experts. The PM-
group is an international consultancy firm who hires engineers, such as Peter J.M. Kerssens, the
owner of Haarlem Hydraulics, who works on the project as an “Urban Drainage and Flood
Management”-specialist, and also is the supervisor of Sebastiaan Quirijns. As a component of
MUSIP a study was performed regarding water supply from Sedawgyi dam/reservoir to
Mandalay city and Sedawgyi irrigation area. This study was executed from the end of July until
the end of October by Sebastiaan Quirijns at the ADB PPTA office in Mandalay. The modeling of
the water resources in the selected project area was done with the program “RIBASIM” provided
by “Deltares”. An extensive training-course for the RIBASIM program was given by Wil van der
Krogt, a RIBASIM specialist at Deltares.
This study and report is done by Sebastiaan Quirijns to finalize his internship at Haarlem
Hydraulics and the Technical University of Delft. An internship of at least two months has to be
performed during the master phase of Civil Engineering at the Technical University of Delft. The
faculty of Civil Engineering values an internship with 10 ECT’s, which is equivalent to ca. 280
working hours.
1.1 Project description
The study performed for MCDC is done in the context of the Project Preparation and
Technical Assistance (PPTA) for Mandalay. As mentioned before the project is to improve the
urban services in Mandalay, such as drainage and flood protection, solid waste handling, waste
water treatment and water resources for public water supply and irrigation, but also social
surveys and capacity building.
The purpose of this component is to simulate the water demand and supply of the
Sedawgyi irrigation area and Mandalay City. In order to aid the ADB PPTA, this report
contributes by visualizing the problems that occur and testing multiple scenarios for
improvement of the water usage efficiency.
Mandalay has a monsoon climate, with a clear dry season and rain only during the rainy
season. Most of the water supply is controlled by the Sedawgyi Multipurpose Dam. The water is
accumulated in the Sedawgyi Lake for irrigational use and hydropower. Problems have risen
that there is too much spillage of water during the rainy season, while during the dry season
there is a shortage. The secondary function of the dam is generation of electricity by producing
hydropower. There is currently no clear operational combination of both functions regarding
the downstream water and power demand. This results in a very low efficiency of water usage
efficiency. So logically the goal of this research is:
“Modeling the water resources in the Mandalay region in order to raise the water usage
efficiency”
In this respect there is a secondary risk which needs to be analyzed. Due to the heavy
rainfall, in the mountains in the east of Mandalay, a lot of water will flow towards the city. A
potential solution which needs to be studied, in order to lower the flood risk, is a side channel
around Mandalay, i.e. a collector drain at the foot of the Shan mountain range, or a second
reservoir. However, in RIBASIM it is not possible to calculate flood waves or water level based
on the elevation of the area. Consequently, the only way to look into this option is by considering
the potential discharge capacity for flood waters.
1.2 My objective
As mentioned before, during this internship I have studied the water resources of the
Mandalay region and processed the data in RIBASIM. The data were provided by the Mandalay
City Development Committee (MCDC), and the local Irrigation Department (ID). When the data
were not available a field research was executed.
The water supply to the area of interest is regulated by the Sedawgyi dam. The primary
function of this dam is for irrigation use, and secondary is the hydropower production. At the
moment too much water is lost, because it is not used by irrigation or the city. The demand and
supply were modeled in the RIBASIM program. In this way a more efficient use can be simulated
and may serve to get better insight into the project area and the water utilization. As a result the
consultants can give better advice to MCDC. A second part of the research was to investigate the
possibilities to lower the flood risk by constructing a side channel. Multiple scenarios were made
in RIBASIM to analyze the response of the system.
1.3 Scope of the project
In this research some boundaries have to be set. The outer limits of the project area are
the Ayeyarwaddy River to the west, Sedawgyi Lake to the north, the Shan Hills on the east, and
the Dokhthawaddy River in the south. See figure 1 on the next page for a clear figure of the
boundary limits.
RIBASIM is a model that simulates the demand and supply in a surface water system. This
is built up of nodes that are either supply or demand, and links connecting the nodes. When a
demand node sends a request to the supply node a water allocation is made, based on priorities
and the total amount of water available.
Regarding the scope of research in the water resources system, all the water supply is
controlled by Sedawgyi Dam. Two catchment areas are located in the Shan Hills and are
simulated as a time series due to precipitation. Next is that Mandalay city is modelled as three
nodes, considering Public Water Supply (PWS), Moat flow around the Royal Palace, and the Non
Revenue Water (NRW). NRW is water losses in the distribution system of Mandalay. The
irrigation canals modelled are the primary and secondary canals of the Sedawgyi irrigation
system. Looking at the agricultural area, multiple farms are clustered into one area. This is no
loss of accuracy since it is possible to assign multiple crop sorts to one area. Finally, the ground
water flow is excluded as an inflow, but taken into account as an outflow (drainage) in the
irrigation area.
As mentioned before, it is not possible in RIBASIM to calculate flood waves or putting an
elevation (water levels) and/or slopes into the system. Another difference with RIBASIM is that
the flow in the links is determined by the demand nodes and allocation settings.
Internship Report by Sebastiaan Quirijns Sedawgyi Water Resources/Irrigation system simulations
Haarlem Hydraulics & Technical University of Delft | Introduction 11
Note: Significance is too accurate for such estimation, yet this seems to be common in Myanmar
A quick and dirty estimation has been done by the ‘ADB PPTA’ Urban Planning section
for a population projection in 2040. The estimation is based upon two former censuses and the
estimation of the Ministry of Population. These censuses were done in 1984 and 2014, so thirty
years apart. For estimating the total amount of inhabitants an educated guess has been made
with multiple scenarios including population growth, urbanization and two developing areas in
Amarapura and Patheingyi. The results are given in table 3. It is estimated that in 2040 the
development plan for Amarapura is finished for 90% and in Patheingyi for 60%. This difference
is a result of the existing trend of extending the city in southward direction, and in addition the
roads are in better condition compared to Patheingyi. However, as mentioned, these
expectations are quite uncertain.
90% in DA1 and 60% in DA2 by 2040 Township/area Total Population Phased % AAGR 2014-20 2021-30 2031-40 2014-2040 Aungmyethazan 190423 215746 241070 0,51
In table 4 a list is given of the five largest irrigation areas fed by the MMC. For the whole table see Appendix II-B2: ‘Salient features of the Mandalay Main Canal’
2.1.1.7 Water level and major threats
In Mandalay there are some major issues with regard to the water resources. An increase
of water level can be caused by multiple reasons. The issues that are analyzed and included in
the research for the RIBASIM Model are enlisted below:
Causes for increase of flooding risks in Mandalay
o By rainfall
o By internal failure of the water (drainage) system
o By overflowing of the river flood protection infrastructure (dykes)
An investigation into the causes of flooding of Mandalay has been performed by the
TEAM Consultants, together with CH Karnchang Public Company ltd and the Warninn Group of
companies. They established a presentation of the potential causes for failure of the flood
protection system in Mandalay given in Figure X. However, the overflow of the Ayeyarwaddy
River into the city does not seem to be realistic, since the height of the dike is sufficient.
In order to construct the rainfall dataset, in 2039 and 2040, the formula underneath is
applied. The existing measurements until 2014 are extrapolated by using the existing set and
multiplied with the corresponding climate change factor per season to the power n which is
from 2014 to 2040, thus 26 years.
𝑅𝑛𝑒𝑤,𝑖 = 𝑅𝑜𝑙𝑑,𝑖 ∗ 𝑐𝑐𝑛
Equation 1 Extrapolation Rain data
Rnew,I = New rainfall value ith in the list per rainfall measurement station. Rold,I = Rainfall value ith in the existing set per rainfall measurement station cc = Climate change factor for rainfall, see table X2 n = Number of years after 2013 to 2040; n=1 to 26 years
2.1.1.9 Agriculture
In the Sedawgyi Irrigation Network there is much agriculture. On the 30th of July 2014 a
field trip was made to the Sedawgyi Dam; see Appendix I-I and Appendix CD for photos. Along
the main road to the dam a quick and dirty estimation has been made about the variety of crops
produced. Main crops produced are (logically) rice, and some other productions in large
quantities are sugar, banana, corn and wheat. For the distributaries a reference is made to
chapter ‘Primary and secondary canals’, also to Appendix II-B.2: ‘Sedawgyi Dam Network
Irrigation Map’& Appendix II-B.3: Mandalay Canal Irrigation System
Internship Report by Sebastiaan Quirijns Sedawgyi Water Resources/Irrigation system simulations
Haarlem Hydraulics & Technical University of Delft | Initial analysis of the project area 23
2.1.1.9.1 Agricultural Areas
The Sedawgyi Dam Irrigation Network can be divided in four areas as shown in table 6.
Area description Township/Weather station
Location Supplied by
DY1 to DY 9 Madaya Along Yenatha Canal Yenatha Canal Pumping Area L1-L16
Patheingyi East of the Mandalay Main canal
Mandalay Main Canal
Western area of the Irrigation network
Patheingyi/Mandalay/Madaya
From Seiktha Cut to Patheingyi DY
Mandalay Main Canal
Southern area of the Irrigation network
Mandalay/ Amarapura From YanKinGon DY to Kinbek DY
Note: Summer and winter paddy areas are equal, because the assigned area can be in different
periods. Only one of the assigned areas is included in the calculated sum.
Summation of the assigned areas for all specified crops and other agricultural in
Mandalay are shown in table 7. Therefore some crops are included, but not modelled. These
crops were not seen in Mandalay, but definitely grown in Myanmar and are probably around
Mandalay as well.
Many banana and mango cultivations were seen in the field, but it was not possible to
model these. So they are excluded from the model. It was not possible to model these, due to the
fact that growing period exceeds a single simulation year which will lead to no production of
crops.
For a small summary about the characteristics applied for the crops reference is made to
Appendix I-B2: ‘Background information crop data’& Appendix I-D: ‘RIBASIM Background’
2.2 Water Resources
The analysis of the water resources system is covering the supply and demand by a variety
of aspects in the system. First the supply side is covered, which consists logically of the Sedawgyi
Lake and local rainfall as an additional source. Secondly, the demand side consisting of multiple
elements such as water usage by Mandalay inhabitants, loss flow and a constant flow in the
Moat. (base flow for water quality reasons).
2.2.1 Supply
First the Sedawgyi water balance will be handled, hereafter the rainfall measured at the
different stations and the corresponding inflow.
2.2.1.1 Sedawgyi Lake
The Sedawgyi dam is located at the Chaungmagyi river in Madaya and is the main supply
for the irrigation network. The main objective of the dam is to supply enough water to increase
Internship Report by Sebastiaan Quirijns Sedawgyi Water Resources/Irrigation system simulations
Haarlem Hydraulics & Technical University of Delft | Initial analysis of the project area 25
the agricultural output in Mandalay, Yenatha and the pump irrigation areas. These objectives
have been planned under the project by provision of sufficient irrigation canals for growing
crops. The irrigation construction works are integrated with the agricultural and fisheries
development program. Secondary benefits could be derived from the generation of hydropower
at the dam site and for the increase of water supply to Mandalay. (Irrigation Department, 2014)
Consequently, the dam can regulate the discharges from the Chaungmagyi river as
required, resulting in an increased acreage of about 32000 acres on top of the existing acreage of
95000.
It is not clear what the main function is of the Sedawgyi dam. The Super-intendant said it
is used for both irrigation and hydropower4. Nevertheless, it was clearly visible that during
drought water is accumulated for hydropower resulting in a shortage of water for irrigation. On
the other hand, during the rainy season the water level is too high in the lake, so the spill gates
have to be opened. This leads to a large flow going downstream of the dam into the irrigation
network. A lot of water is wasted this way because in the rainy season it is unused by the
farmers. This all leads to a low overall efficiency of water usage.
The annual and daily water balance of the last years was supplied by the Irrigation
Department. The annual water balances for Sedawgyi Lake is included in the Appendices B.10 &,
CD. The inflows of the water balance are inflow by Chaungmagyi River and rainfall at the lake.
This rainfall is measured at the Madaya meteorological monitoring station. The overall rainfall in
the project area is measured at four stations, being Mandalay, Amarapura, Patheingyi and
Madaya. All of the DYs are sorted within one of the weather stations. This is presented in table 8
and in Appendix II-B3
Township Mandalay Amarapura Patheingyi Madaya
Mandalay Main Canal DY’s
Shwe Ta Chaung Tadaing She Shwe Ta Chaung Seiktha
Patheingyi Tamok So Kabed Feeder Cut Kyauk Mi Kinbak Lundaung ShweTaChaung Tadaing She Nanda Lat Kaung Kyauk Than Bat Alebon Patheingyi Htanbingon Yankingtaung Lundaung Yekyi Nanda 168 Minor Wangingon Kyauk Mi Tadaing She
4 Appendix I-I: Interview with head of Sedawgyi Dam & Appendix CD; Photos of fieldtrips, Sedawgyi Dam
In table 8 the largest DY’s are in bold which have the largest size of the agricultural area
in the corresponding weather station above. As mentioned, the half monthly data for the rainfall
per measurement station are included in the CD.
The precipitation at Sedawgyi Lake and over the cultivation fields are given in mm/day.
This has been converted to a half monthly basis in mm/ (15 or 16) days, also taking leap years
into account. There is nevertheless a large difference in the capacity between the lake and the
fields, as the fields have a “rectangular” shape, but the lake is a reservoir in which the surface
area and the volume increase during rainy periods when the water level rises.
There are no data of the rainfall at the Shan Plateau, and the rainfall measurements of
Patheingyi are not representative for rainfall in a mountainous area. Therefore the rainfall
measurements of Pyin Oo Lwin are applied as representative measurement. Since the Shan
Plateau and Pyin Oo Lwin are both located in mountainous areas, it is to be expected that the
amount of rainfall is more or less similar in both locations.
2.2.2 Demand
The demand for water is the major part of this research. It consists out of a variety of
specific water demands, distinguished as follows: the demand for public water supply
(population, business, and industry), water demand for irrigation, the moat flow (flushing for
water quality), commercial losses, and physical losses.. In the model the allocation of water is
determined by priorities set by either the amount of water or socio-economic significance. For
instance, in almost all cases drinking water for people will have the highest priority.
2.2.2.1 Sedawgyi Reservoir
The full water balance is:
𝑑𝑉𝑟𝑠𝑣𝑑𝑡⁄ =
𝑑𝑄𝑖𝑛𝑑𝑡⁄ −
𝑑𝑄𝑜𝑢𝑡𝑑𝑡⁄ −
𝑑𝑆𝑜𝑢𝑡𝑑𝑡⁄ + 𝐴𝑠𝑢𝑟𝑓𝑎𝑐𝑒,𝑖(
𝑑𝑅𝑖𝑛,𝑖𝑑𝑡⁄ −
𝑑𝐸𝑜𝑢𝑡,𝑖𝑑𝑡⁄ )
Equation 2 Water balance
dVrsv/dt Volume of the reservoir over time [m3/ts] dQin/dt Inflow by Chaungmagyi over time [m3/ts] dQout/dt Outflow through hydropower outlet [m3/ts] dSout/dt Spillage over main gates [m3/ts] Asurface,i Corresponding surface area [m2] dRin,i/dt Rainfall over corresponding lake surface area [mm/ts] dEout,i/dt Evapotranspiration of the lake surface area [mm/ts]
The measured values are summarized in a table for this water balance at Sedawgyi Lake is in Appendix II-B.10. Since the reservoir is not a cylindrical shape, but more like a bowl shape, the volume and corresponding surface area in the reservoir vary in time with the water level, due to in and out flow in the reservoir. The water balance of the reservoir represents this. For retrieving more insight into the volume change, respectively the change in water surface area based on a certain water level an area/volume curve for the Sedawgyi Dam is given, see figure 9 or Appendix II-B11.
Internship Report by Sebastiaan Quirijns Sedawgyi Water Resources/Irrigation system simulations
Haarlem Hydraulics & Technical University of Delft | Initial analysis of the project area 27
Non Revenue Water (NRW) is a term for water usage for which the public is not charged.
This NRW consists of two main aspects, namely commercial and physical losses.
Physical losses
o Leakages
o Overflow
Commercial losses
o Under counting
o Illegal connections
o Unbilled consumption
Unbilled consumption forms a high contribution to the total NRW, due to monks,
governmental buildings and the military. These groups do not have to pay for public services.
The difficulty is that there are simply no data about the amount of water for physical or
commercial losses. So a quick and dirty estimation has been executed to acquire some insight
into public water supply. Table X on the next page shows this estimation.
Internship Report by Sebastiaan Quirijns Sedawgyi Water Resources/Irrigation system simulations
Haarlem Hydraulics & Technical University of Delft | Initial analysis of the project area 29
Description Value Unit
Total Inhabitants in 2014 1,220,000 Nr. of people
People Connected to water network 2013
700,000 Nr. of people
Paying Households 85,200 Nr. of customers Supplied water in 2014 96,900 m3/day Non Revenue Water 60,600 m3/day Billed water 36,300 m3/day Billed Water Percentage 37 % NRW Percentage 63% % PWS Calculated 101 l/capita/day 15% by surface water 15 l/capita/day 85% by groundwater 86 l/capita/day
The moat is located around the Royal Palace. Every outer side is ca. 2.3 km. The moat in
combination with the Royal Palace is one of the major touristic sights in Mandalay. This is why
the City Council demanded that there should always be a certain minimum flow and a nearly
constant water level inside the moat.
The flow has never been measured, but an estimation of 10 m3/s has been made.
2.2.3 Sedawgyi Irrigation area
All the cultivations need a certain amount of water. The allocation of water is modelled
by the RIBASIM Program. The demand for water is based upon some pre-mentioned
characteristics, such as percolation, pre-saturation, crop factor, yield crop factor and field buffer
storage. See Appendix B5 for the applied values. All of the required data have been acquired via
the FAO (Food and Agriculture Organisation of the UN, 2014).
One of the most common crops after paddy fields is sugarcanes. The sugarcane is applied
as an illustrational crop in Appendix II-B2, because it has a distinctive growth curve. Yet all the
other crops have been researched in a similar way.
2.3 Civil objects and canals
Within the Sedawgyi Irrigation Network the major civil object is the Sedawgyi dam. The
primary and secondary canals are investigated as well. Some ‘hard’ figures are presented in this
chapter.
2.3.1 Sedawgyi Dam
The ‘hard’ data of the Sedawgyi dam consist of: cross-section, hydropower, units,
turbines, etc. A summary of the data is presented in the following table. The extensive data for
‘Salient Technical Features’ and ‘Hydropower Generation Stages’ are shown in Appendix II-B2
and Appendix CD, respectively.
Sedawgyi Dam key values Corresponding surface area
Corresponding capacity
Characteristics [m] [ha] [m3] Length of dam 1255,8 Top of Dam, (above MSL) 131,4 Max Water Level, (above MSL) 129,5 Full Reservoir level, (above MSL) 127,9 2870 4.48*108
Min Operating Level, (above MSL) 111,3 1380 1.04*108 Catchment Area 342,500 Hydropower Installed Nr [MW] Capacity 2 12.5
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Haarlem Hydraulics & Technical University of Delft | Scenarios 35
4 Scenarios The main problem is the low efficiency of the water use. Large cultivations are drying out
and most of the time there is water shortage. The efficiency is so low, because water is
accumulated for hydropower. So the farmers don’t get enough water to produce crops during
summer and winter season. On the other hand, during the rainy season the flow through the
turbines is limited by the maximum capacity. So water gets spilled by opening the spillways.
Even more so, there is too much water flowing into irrigation network which is unused and
causes a potential flooding hazard in the city or along the canals.
The main goal of the scenarios is to improve the water usage efficiency. In the scenarios
some options are designed to improve the efficiency in 2040. The long term effects are the
autonomous developments in 2040. Most of the scenarios are based upon existing design,
potential designs or conceptual designs for future development. These scenarios are all
supported by ‘ADB PPTA’ or M.C.D.C. (Appendix Fieldtrips & Interviews). So all the designs are in
different phases, but the goal of this study is to check the different results per scenario in 2040.
Water shortage is currently already a major issue, but in 2040 the long term effects will
only increase this demand significantly. The results of the scenarios will be tested to efficiency.
However water efficiency can be measured in multiple criteria, these are called the design
criteria. Ultimately, the improvement of the ‘Quality of life’ is basically the main issue.
4.1 Long term effects
Logically in 2040 some others effects are at play then in 2014. The long term effects are for
instance the autonomous developments up to 2040. This means without any influence by the
ADB PPTA. Planned activities not executed by M.C.D.C. are also included in the list of long term
effects as given below, since these planned activities by for instance Madaya City Council will
happen in any case.
Climate change effects in the Sedawgyi Irrigation Network region;
Reduced return flow to surface water up to 37% in urban areas. As a result of two
processes, such as the increase in urban density and increase of asphalt cover;
Mandalay has increased to approximately 2.3 million inhabitants;
Madaya has increased to about 0.1 million inhabitants and is connected to the Sedawgyi
Reservoir. The NRW- losses are assumed to 25%, mostly commercial.
For support of the long term effects, which are not treated in the main report, see Appendix
I- F.1.
4.2 ADB PPTA Plans
The ‘ADB PPTA’ already has many existing design plans for 2040 to improve the urban
services in Mandalay. The urbanization, public welfare and population increase for Mandalay in
2040 result in significantly higher demands for water that cannot be covered by the existing
system. In Appendix I-F.2, the support information of these plans is presented further. The
following list summarizes the long term design plans.
‘M.C.D.C’ and ‘ADB PPTA’ have increased the total coverage for water supply to 95% in
Mandalay (= ±2.19 million people)
Mandalay has increased usage of surface water to 47%, which is equal to ca 150000 m3
per day (ca. 68 l/capita/day).
‘M.CD.C.’ and ‘ADB PPTA’ have reduced Mandalay’s NRW-losses to 10%
4.3 Design criteria
The improvement of water usage efficiency in 2040 is considered the main goal of the
scenarios. However, the goal is still quite ambitious, so a more specified classification is
required. This is achieved by setting some design criteria, in order to satisfy a clear distinction
between the outcomes of the scenarios. The design criteria are divided in ‘hard’ and ‘soft’
criteria.
The hard design criteria are physical and easily measured:
Reservoir volume
Reservoir spillage
Net in- and out-flow of the reservoir
Generation of hydropower
Actual cultivation areas
Supply/demand ratios for cultivations
Irrigation efficiency
Supply/shortage for PWS
Continuous flow in the moat canal
The soft criteria are harder to measure, since they are a reflection of the ‘Quality of life’.
Obviously this is somewhat vague, but these criteria describe the required effect at best.
Clean drinking water
Continuous distribution of water
No flooding of the urban areas
Mandalay Green City
More variety in cultivated crops and food
Beautification of Mandalay
Reservoir should never be empty
Although not all of these criteria can be modelled with RIBASIM, yet they still have a
major influence in improving the ‘Mandalay Urban Services’. In Appendix I-C , these criteria are
covered more extensively, because there originated from the ‘Green Cities’ ideology by ‘ADB’
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Haarlem Hydraulics & Technical University of Delft | Scenarios 37
4.4 Constructing the scenarios
All the scenarios consist out of options, i.e. single measures to improve the water usage
efficiency regarding the design criteria. As mentioned previously, these options are potential
designs or ideas. All these potential options have been collected during the feasibility study done
by the ‘ADB PPTA’. The corresponding information has been acquired by discussing with a
variety of stakeholders, i.e. ‘M.C.D.C., ‘ADB PPTA’ - members and Irrigation Department. In table
X a list is given of all scenarios and their intended results. The first two are standard scenarios
that are applied in every single model, for calibration and visualization of the problems in 2040.
The third scenario is the ‘ADB Reference Case’. In this scenario all the ‘ADB PPTA’ plans for
Mandalay have been implemented. The probability that these plans will be executed is quite
high. At the same time these ‘ADB’ Plans are to increase the ‘Quality of Life’ in and around
Mandalay, which results in a higher demand for water. Therefore this scenario is also applied as
a reference case for the other potential or conceptual scenarios. The ideology behind all
scenarios are given in Appendix I-F3
Index Scenarios Time Description Intended results
1 Base Case 2013 to 2014
Current situation -Visualizing the problems -Calibrating the model
2 Do Nothing Case (DNC)
2035 to 2040
All autonomous long term effects are in effect.
-Visualizing the problems if no action is undertaken -Comparing the other scenario’s
3 ADB Reference Case
2035 to 2040
-Including all long term effects -Including all ADB PPTA Plans
-Increase welfare -Reduce losses -Increased water demand
4 Sustainable Urban Drainage System (SUDS)
2035 to 2040
Construct SUDS in Mandalay and Madaya
-Improve drainage to increase return flow to surface water -Reduce flooding and water spillage - Beautification of Mandalay
5 Capacity Training Agriculture (CTA)
2035 to 2040
Increase the irrigation efficiency by improving the material and capacity of irrigation
- Increased efficiency -More welfare farmers
6 Secondary Open Channel (SOC)
2035 to 2040
-Construct an secondary open channel to redirect flood water from Shan Plateau to the Mandalay Main canal -Redistribute the water over the Southern Sedawgyi Irrigational Area.
-Reduce flood risk -More water supply -Increased cultivation areas
7 Separation of Water Resources Systems (SWRS)
2035 to 2040
-Irrigation area gets solely supplied by Sedawgyi Dam -Mandalay is supplied solely by other sources
Average Monthly Shortage 2040 0,00 0,00 0,00 0,00 0,00 0,00
Average Monthly Supply 2040 0,03 0,03 0,03 0,03 0,03 0,03
Average Monthly Shortage 2039 0,00 0,00 0,00 0,00 0,00 0,00
Average Monthly supply 2039 0,03 0,03 0,03 0,03 0,03 0,03
0,00
0,01
0,02
0,03
0,04
0,05
0,06
Yearly Supply & Shortage [m3/s]
Average Monthly flow supply and shortage Madaya
BaseCase
DNC ADBSUD
SCTA SOC
SWRS
Average MonthlyShortage 2013-2039
2,05 3,90 3,97 3,91 3,58 3,98 0,00
Average Monthly Shortage2014-2040
0,42 3,99 4,05 3,99 2,95 4,05 0,00
Average Monthly Supply 2014-2040
9,58 6,01 5,95 6,01 7,05 5,95 0,00
Average Monthly Supply 2013-2039
7,95 6,10 6,03 6,09 6,42 6,02 0,00
0,005,00
10,0015,0020,0025,00
Yearly Supply & Shortage [m3/s]
Average Monthly Water Supply-Shortage Moat
The demand is equal for all cases, because there is no variety per scenario. In the long term
it is clear that there is an increase in shortage. So fluctuations in water level will occur or a loss
of flow velocity.
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7 Conclusion and Recommendations The simulations are performed and the results analysed on basis of the hard design
criteria. So now some conclusions and recommendations will be formulated in this chapter. The
conclusions subsection will be done in a checkmark way and treat every point of interest
separately. First some basic conclusions about the modelling, later more specific conclusions per
scenario are presented.
7.1 Conclusions
The conclusions will start with the overall conclusions, then more into detail.
7.1.1 Overall
The surface water network of the Sedawgyi irrigation area and Mandalay city was
modelled in detail as a basis for the RIBASIM schematization. Information and data about
reservoir operation, hydropower production and reservoir releases on Sedawgyi
dam/reservoir were provided by the local Irrigation Department.
With this model a successful calibration was executed for the water resources conditions
in the Sedawgyi irrigation area and the public water supply for Mandalay city in the
years 2013 - 2014.
The model, not surprisingly, shows clearly that in 2040 as a result of the expected
population growth and increased urbanization, large water shortages will occur for both
public water supply and irrigation, if no additional corrective measures are taken (do-
nothing scenario)
The deterioration of the water supply situation will be strengthened by the expected
climate change effects in 2040.
The conclusion above results in low supply demand ratios, low actual cultivation growth
and more spillage. If no measures are undertaken to reduce these effects, some serious
issues will arise in the Sedawgyi Basin regarding Mandalay city and agriculture.
Some notes have to be stated about the scenarios. The increase dependency of surface
water for PWS in Mandalay will never occur as there are already plans to shift from the
present sources to more river water withdrawal, including for instance a new PWS plant
at the Dokhthawaddy. Nevertheless, the cases have been modelled this way, because it is
always a good modelling incentive to prove from the absurd/extreme values.
7.1.2 Scenarios
All results of the scenarios are discussed separately.
7.1.2.1 Do Nothing Case
It was clearly visible that in all results this case did not make any of the requirements.
The water supply is kept mostly in the reservoir and the water does not get allocated towards
downstream purposes. Obviously this leads to low supply/demand ratios for PWS, Moat,
agriculture etc.
7.1.2.2 ADB Reference Case
Large increase in the network coverage to 95%, a reduced NRW to 10% and increase
dependency on surface water coming from the Sedawgyi leads combined to a significant
increase in water demand. Yet there is still something to say about the 10% NRW, since the
commercial losses, for legalized supply, are not easily adjusted.
Results of this case are that more water is supplied to the PWS of Mandalay and Madaya,
which results in a lower supply for the remaining distributaries. However there is still some
water left for supplying a number of cultivated areas with higher priorities. In the lower
prioritized cultivated areas there are some losses in cultivated areas. This is also visible for the
supply demand ratios in the corresponding areas, which are relatively low in 2039 and 2040
compared to the current situation.
7.1.2.3 SUDS
Sustainable Urban Drainage Systems (SUDS) are strongly recommended to improve
urban drainage and flood management in and around Mandalay city, but will have a relative
small effect on the water resources/water supply conditions.
7.1.2.4 CTA
One of the most effective measures to improve the situation is to increase the irrigation
efficiency, reducing losses in the system and ensuring that irrigation water will be delivered at
the right moment and the right place. Although it is not easily done to convince farmers to apply
new materials and methods, but it is definitely something to consider. The results for a higher
efficiency are excellent. The gross supply is lower and efficient supply higher, so less losses in
irrigation. This corresponds to more water availability overall, which results in higher cultivated
areas and an increase in the potential supply for PWS.
7.1.2.5 SOC
A collector drain at the Shan plateau foothills is strongly recommended as it will be
effective to reduce the flooding problem in Mandalay city, but will not do much for the water
supply situation.
There is some visible increase in the Southern Sedawgyi Irrigation cultivated areas and
the corresponding supply demand ratios. But the increase is not significant. One of the design
flaws in the current model is that it has been modelled as an open channel, while a combination
with canal and detaining pond might be a better solution. In that way the water can be stored
and distributed more evenly over the drought period, instead of just a passing flood wave like in
the current model.
7.1.2.6 SWRS
This is actually the most realistic design, because the ADB PPTA has plans for Mandalay
to be supplied by other measures from surface water. These measures do not include water
supply from the Sedawgyi reservoir.
Separation of the Water Resources System of Mandalay and Sedawgyi is very effective
for increasing the cultivation areas and ensuring the city water supply. These cultivations react
correspondingly by having an acceptable supply demand ratio, if compared to the other cases.
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7.1.3 Miscellaneous Conclusions
The Asian Development Bank pays a lot of attention to stakeholder participation for
decision making in their projects. On October 18 Focus Group Discussions were held
about floods in the context of the MUSIP project. These meetings were attended by local
inhabitants of flood prone areas, community leaders, NGO’s and representatives of social
groups. One important statement they made was that sometimes areas and people get
flooded due to reservoir releases from Sedawgyi dam. This generally happens without
any warning, and in winter time when water levels are high already.
Floods caused by Sedawgyi reservoir releases generally occur in the North-Eastern parts
of town. Rescue service is provided by the government, but it would be better to provide
flood early warning. Further assistance is given by Red Cross and other NGOs.
7.1.4 Final Conclusion
The Asian Development Bank pays a lot of attention to stakeholder participation for
decision making in their projects. On October 18 Focus Group Discussions were held about
floods in the context of the MUSIP project. These meetings were attended by local inhabitants of
flood prone areas, community leaders, NGO’s and representatives of social groups. One
important statement they made was that sometimes areas and people get flooded due to
reservoir releases from Sedawgyi dam. This generally happens without any warning, and in
winter time when water levels are high already. It can be concluded that a study into an
improved operational scheme and better management of Sedawgyi dam/reservoir will be
necessary sometime in the near future.
Given the current operational settings of the Sedawgyi Dam, it clearly shows that in 2040
Sedawgyi Reservoir could not support both Public Water Supply and irrigation systems. So the
water resources systems of Mandalay and Sedawgyi Irrigation Network should be separated.
Sedawgyi will supply the irrigation and Mandalay will be provided by surface water of the
Ayeyarwaddy and Dokhthawaddy. The modelling results of this study support the choices made
by ‘ADB PPTA’.
If the irrigation efficiency is increased to 90% (i.e. In steps of 50% to 60% to ... to 90%) in
the long term (20 to 25 yrs.) high yields can be achieved, by investments in training, technology
and resources. This will also include lower losses and spillages in the water resources systems.
The current allocation of the dam is not efficient, in such a way that there still is a high
shortage of water supply in the downstream area of the Sedawgyi. In the future the allocation
settings of Sedawgyi Dam should be based upon a hydrological study and including the demands
of all stakeholders.
Since, the ‘ADB PPTA’ already is in a further stage, this study has to be acknowledged by
modelling their choices. So, the Separation of Water Resources System has already been
selected as definitive advice. The modelling results showed the same scenario as best combined
with the increased irrigation efficiency. However, now it is also known that some of the other
scenarios do not influence the situation as much. Yet they definitely have other positive effects
as well. M.C.D.C has to invest in improving the surface water cleaning treatment plans to have
sufficient clean and a secured continuous water availability for PWS of Mandalay. For achieving
high yields of crop productions and a variety in crops with a reducing availability of water by the
long term effects, a modernization of the applied irrigation methods and materials is necessary.
All of this in order to increase the total water usage efficiency in and around Mandalay and to
improve the quality of life.
7.2 Recommendations
It can be concluded from the statements above that a study into an improved operational
scheme and better management of Sedawgyi dam/reservoir will be necessary sometime in
the near future.
It can also be concluded that apparently it is not irrigation that has first priority in the
operation of Sedawgyi dam, but hydropower production. This is quite surprising since
during a visit to the dam in April the Irrigation Department staff claimed that the ID does
not get paid for the hydropower produced.
It is recommended that the allocation of the Sedawgyi will be based on a hydrological
model and stakeholders, instead of the current settings for allocations by the Sedawgyi
Dam
7.2.1 Final recommendation
The most optimal solution is separating the water resources systems for Mandalay PWS
and Irrigation and combine this for the Sedawgyi Network with the increased irrigation
efficiency. In this way the benefits of having the certainty that Mandalay is always supplied by
surface water and little groundwater and the benefits of applying an increased field irrigation
technology, will lead to a significant increase in crop production and cultivated lands.
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Haarlem Hydraulics & Technical University of Delft | Evaluation of applied methods 57
8 Evaluation of applied methods The applied methods in this report consist of gathering information, apply it in RIBASIM
and finally to give an expert view of the simulation results. All three sections will be discussed
separately.
Since, the data was flawed, corrupted or missing, the resulting model had a rather low
accuracy. The time needed to receive the data took quite some time.
RIBASIM was an excellent program to model these situations. It is very clear and easy to use
and when stuck Wil van der Krogt has been a major help. The capacity training to the Burmese
people has not gone as expected, because the education level regarding modelling with
computer programs was fully lacking. There is definitely some ground to cover here for the
Burmese engineers.
After working with RIBASIM for three months, the differences in interpreting of the results
have become clear. Peter Kerssens, Wil van der Krogt and Gary Moys have had a big influence
with their expert view in analysing the results and conclusions.
Ultimately, the study has been a major success in aiding the choices made by the “ADB
PPTA” team. M.C.D.C. and ID do now have the model and after some additional workshops their
capacity should be increased to such a standard that they can adjust the model themselves.
Definitely not everything has been as accurate as it would have been in a western country.
However, if the education level increases, accordingly the data treatment capacity will improve
as well the modelling skills.
9 Assumptions All assumptions made during the current study are enlisted underneath:
Irrigation areas along the Mandalay Main Canal are included in other distributaries, because these could not be modelled otherwise.
Madaya area: MMC Seiktha Mandalay area: NA Patheingyi area: MMC 168 Minor Amarapura area: MMC Kinbak These adjustments led obviously to a too large irrigation area, but also a too large flow
through these links. Same is done for the Yenatha Canal Total applied area per crop sort within a distributary There is no real ratio applied at the Sedaw Weir, just based on downstream demand Simplification of some distributaries areas in to one large node, however this does not
lead to large losses of accuracy, because of the ‘Cropper ‘function within RIBASIM. Averaged demand for PWS of Mandalay is equal for every single person per township All PWS surface water supply is supplied by Sedawgyi Reservoir Simplification of NRW as a distribution loss. In the model there is no clear distinction
between commercial and physical losses. By applying some extreme values during modelling to enhance the differences
between scenarios. This has been done for: o Population growth o Climate change o Irrigation efficiency
10 Recommended topics for further investigation Looking in to the potential risk caused by flood waves in the Shan Hills towards the
irrigation network, since this was not possible within RIBASIM.
Investigate the back water effects of the Ayeyarwaddy in 2040 caused by increasing water
level at sea due to climate change
More intensified research with more detailed/accurate data of rainfall, water balance,
cultivations, etc
Research in to water quality in Ayeyarwaddy and main canals
Study the same basin with updated scenarios by the ‘ADB PPTA’
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12 List of tables Table 1 List of abbreviations ......................................................................................................................................... 4
Climate Information ....................................................................................................................................................... 20