セムコ List of Products and Services

Our company leverages the extensive know-how gained from developing liquid level gauges for the maritime industry, and we have a wealth of achievements in proposals aimed at improving efficiency and reducing manpower related to "liquid level measurement." Currently, in addition to materials introducing our initiatives for promoting DX, we are offering documents that present a total of 10 case studies and solutions, including: - "Reducing maintenance costs for liquid level gauges in food tanks" - "Streamlining processes after measurement" - "Improving visibility of tank liquid level" We can support everything from sensors to the entire system and software development, listening to your concerns and developing while grasping the overall picture. [Content Highlights (Excerpt)] "DX Transformation in White Companies" - Digitization of internal order files - Document management using cloud services for business app development "Case Studies on Efficiency and Labor Reduction in Liquid Level Measurement" - "I want to achieve efficiency in oil delivery" - "I want to prevent pump troubles by improving the efficiency of tank liquid level measurement" - "I want to achieve efficiency in tank liquid level measurement" - "I want to see the liquid level at eye level" - "The liquid is transparent, making it hard to see the liquid level" *You can view the materials from the download button below.

• Other measuring instruments

The cloud-based tank level monitoring app is a service that allows you to measure and check how much liquid is inside a tank. When delivering kerosene, the traditional method required checking the tank levels on-site in every area and refueling accordingly. However, by using this product, you can check the tank liquid levels in advance and efficiently plan delivery and collection routes. If you are struggling with tank level management for kerosene delivery, waste oil collection, agricultural tanks, factory tanks, etc., please make use of this service. 【Features】 ■ Reduction of oil inventory ■ Reduction in the number of deliveries, allowing for more efficient operations. ■ Automatic measurement of liquid levels ■ Simple and easy to read *For more details, please refer to the PDF materials or feel free to contact us.

• Other Software

Our company leverages extensive know-how gained from the development of liquid level gauges for the shipping industry, with a wealth of achievements in proposals aimed at improving efficiency and reducing labor in "liquid level measurement." We are currently offering materials that summarize case studies and examples of problem-solving. We introduce a total of ten cases, including reducing maintenance costs for liquid level gauges in food tanks, streamlining processes after measurement, and improving the visibility of tank liquid level. We can support everything from sensors to the entire system and software development, listening to your concerns and developing while grasping the overall picture. [Contents of the materials (excerpt)] ■ "I want to achieve efficiency in oil delivery." ■ "I want to prevent pump troubles by improving the efficiency of tank liquid level measurement." ■ "I want to achieve efficiency in tank liquid level measurement." ■ "I want to see the liquid level at eye level." ■ "With transparent liquids, the liquid level is difficult to see." *You can view the materials from the download button below.

• Other measuring instruments

TaVCal (Tank Volume Calculating App) is software designed to simplify the processes after liquid level measurement. Traditional liquid volume management methods have faced many challenges, such as errors in conversion after measurement and time-consuming record-keeping. With TaVCal, you only need to input the measured liquid level height into a form, and it automatically calculates the liquid volume. By recording the results, it also automatically generates reports. We also accept customizations based on the customer's situation. *For more details, please watch the video or feel free to contact us.*

• Scientific Calculation and Simulation Software

This document is a collection of case studies that introduces examples of solving problems using the experience we have cultivated with IT and sensing technology. We can provide consistent support from sensors to the entire system and software development, allowing us to grasp the overall picture together and develop accordingly. Please take a moment to read it. 【Featured Cases】 ■ Want to improve delivery efficiency ■ Want to prevent pump troubles by streamlining tank liquid level measurement operations ■ Want to achieve operational efficiency in tank liquid level measurement ■ Achieving operational efficiency in tank liquid level measurement tasks and accurate measurements ■ Want to measure air pressure in a negative pressure compartment on board a ship *This document can be viewed via "PDF Download." We also offer a comprehensive catalog of liquid level measurement devices and monitoring systems.

• Scientific Calculation and Simulation Software

This document highlights five case studies on the use of liquid level gauges in environments with severe vibrations or where highly corrosive liquids are handled. If you are looking for improvements in safety, work efficiency, or maintenance efforts related to liquid level measurement, please take a look. 【Featured Case Studies】 ◎ Improved safety by switching from glass liquid level gauges to float-type liquid level gauges ◎ Reduced maintenance efforts through the use of ultrasonic liquid level gauges ◎ Enhanced visibility of liquid level in transparent liquids ◎ Non-contact measurement of liquid levels in corrosive liquids ◎ Liquid level measurement in a temperature range of -200 to +450°C *This document can be viewed via "PDF Download." A comprehensive catalog of liquid level measurement devices and monitoring systems is also available.

• Other measuring instruments

The portable tank level gauge "Smart Sounding Scale Honesty" is widely adopted by commercial ships navigating around the world and vessels of the Coast Guard, contributing to the "reform of ship operations." 【Features】 ■ Easy → The sensor at the tip of the measuring device notifies you with a lamp and buzzer as soon as it reaches the liquid level. Accurate and quick measurements can be taken without any skills or experience. ■ Short Time → Measurement time per tank is significantly reduced to about 1/4 compared to conventional methods (according to our research). ■ Accurate → It measures only the actual liquid level without reacting to bubbles formed on the liquid surface. 【Usage Examples】 ■ Ship Fuel Measurement → Accurately measures the actual liquid level while ignoring bubbles on the liquid surface (cappuccino bunker countermeasures). ■ Level measurement of transparent liquids (MGO (Marine Gas Oil), ballast water (seawater), fresh water, etc.). ■ Overflow Alarm → Set the sensor at the planned liquid level position, and it will sound an alarm when the liquid level reaches that position (such as during marine fuel replenishment). *For more details, please download the PDF or feel free to contact us.

• Other measuring instruments
• Foundation construction
• Ground foundation construction method

We would like to introduce a case study on solving issues with marine engine room tanks. Previously, crew members had to climb ladders to check the liquid level in the tanks using glass level gauges, which led to the concern of wanting to "see the liquid level at eye level." As a solution, we adopted a box-type float level gauge, allowing for the display to be checked at eye level, which improved efficiency and enhanced work safety. 【Overview】 ■ Case: Marine engine room tank ■ Concern: Wanting to see the liquid level at eye level ■ Proposed product: Float level gauge - By installing the tank level indicator in an easily visible position, safe confirmation of the liquid level can be achieved. *For more details, please refer to the PDF document or feel free to contact us.

• Other measuring instruments

We will introduce a case study of problem-solving for a sake manufacturer. They were using a float-type level gauge, which incurred significant annual costs for maintenance and cleaning of the moving parts. Therefore, we proposed an external ultrasonic level gauge. Since there is no need to install a sensor inside the tank, it is easier to maintain and does not require frequent cleaning, which can reduce maintenance costs. 【Overview】 ■ Case: Sake Manufacturer ■ Issue: Want to reduce maintenance costs for food tanks ■ Proposed Product: Ultrasonic Level Gauge (External Type) - By attaching the sensor to the outside of the tank, the liquid level inside the tank can be measured. *For more details, please refer to the PDF document or feel free to contact us.

• Other measuring instruments

We would like to introduce a case study that solved issues for a chemical manufacturer (sodium hypochlorite tank). There was a problem with using a glass liquid level gauge, as the liquid was transparent and difficult to see. Therefore, we proposed a diaphragm liquid level gauge. It allows for easy visibility of the liquid level at a glance in one location, and installation is simple. [Overview] ■ Case: Chemical manufacturer (sodium hypochlorite tank) ■ Issue: Transparent liquid makes it difficult to see the liquid level ■ Proposed product: Diaphragm liquid level gauge - No power supply required and easy to install *For more details, please refer to the PDF document or feel free to contact us.

• Other measuring instruments

We would like to introduce a case study that solved problems with tanks containing highly corrosive liquids. There was an issue where "in types that measure liquid levels by contacting the liquid, the parts in contact with the liquid are prone to damage due to corrosion and need to be replaced frequently." Therefore, we proposed a radar level gauge. By installing it on the tank top, it can measure without coming into contact with the liquid. 【Overview】 ■ Case: Tank with highly corrosive liquid ■ Concern: Want to measure the liquid level without direct contact with the highly corrosive liquid ■ Proposed product: Radar level gauge - Can measure the liquid level without direct contact with the liquid *For more details, please refer to the PDF document or feel free to contact us.

• Other measuring instruments

We would like to introduce a case that solved issues with marine LPG tanks and marine LNG fuel tanks. "There was a problem that, due to the nature of ship tanks, there is a lot of vibration and liquid sloshing, making movable types like float switches prone to breakage, and there are not many level switches that can be used across a temperature range of -200 to 450°C." In response, we proposed an ultrasonic level switch. Since the liquid contact type ultrasonic switch has no moving parts, there is no concern about sensor damage even with vibration and liquid sloshing. Additionally, it can handle a wide temperature range with just one type, making it suitable for various liquid temperatures. [Overview] ■ Case: Marine LPG Tank / Marine LNG Fuel Tank ■ Concern: Measuring liquid levels within a temperature range of -200 to 450°C ■ Proposed Product: Ultrasonic Level Switch - The ultrasonic waves within the lot utilize the principle that the lot itself contacts the liquid, allowing the ultrasonic waves to penetrate the liquid surface and output a contact signal. *For more details, please refer to the PDF document or feel free to contact us.

• Other measuring instruments

We would like to introduce a case study that solved the problem of wanting to improve delivery efficiency. Previously, it was unclear how much oil needed to be replenished without physically checking the oil level in the tank on-site. As a result, excess oil was purchased and delivered, leading to cash flow deterioration and the occurrence of leftover oil disposal. To address this, we implemented a remote liquid level monitoring system using the cloud. This led to a reduction in oil inventory and a decrease in the number of deliveries. [Overview] ■ Case Study: Oil Delivery and Waste Oil Collection ■ Problem: Wanting to improve delivery efficiency ■ Proposed Product: Remote Liquid Level Monitoring System (Cloud Version) - Can reduce unnecessary deliveries and excess oil inventory. *For more details, please refer to the PDF document or feel free to contact us.

• Monitoring and Control Equipment

We would like to introduce a case study that solved the issue of wanting to prevent pump troubles by improving the efficiency of tank liquid level measurement. Crew members were unable to accurately calculate the timing of when the ballast tank would run out of liquid, leading to the pump running dry and causing pump troubles. To address this, we implemented tank capacity calculation software (Tank App). This software automatically calculates and records data, allowing for a clear overview of the total ballast remaining, which enables the calculation of the time until complete discharge and helps prevent pump troubles. 【Overview】 ■ Case Study: Ship Ballast Tank ■ Issue: Wanting to prevent pump troubles by improving the efficiency of tank liquid level measurement ■ Proposed Product: Tank Capacity Calculation Software (Tank App) - No time spent on recording or calculations - Time saved can be used for other tasks - If tank data is in digital format, it can be automatically read *For more details, please refer to the PDF document or feel free to contact us.

• Scientific Calculation and Simulation Software

We would like to introduce a case that solved the issue of wanting to improve the efficiency of tank liquid level measurement operations. Previously, all tasks from liquid level measurement inside the tank to capacity calculations, and even record-keeping and tax office submission documents, were done by hand, which took a lot of time. To address this, we implemented tank capacity calculation software (Tank App). This software allows for automatic calculations and records, and reports can be generated with the push of a button, significantly reducing the time spent on tank calculations and document preparation. [Overview] ■ Case: Sake Tank ■ Issue: Wanting to improve the efficiency of tank liquid level measurement operations ■ Proposed Product: Tank Capacity Calculation Software (Tank App) - No time-consuming bookkeeping or calculations - Time saved can be used for other tasks - If tank data is in digital format, it can be automatically read *For more details, please refer to the PDF document or feel free to contact us.

• Scientific Calculation and Simulation Software

We would like to introduce a case study that addresses the challenges of improving the efficiency of tank liquid level measurement operations and achieving accurate measurements. In the fuel tank, bubbles formed on the liquid surface, and when measured with conventional scales, the height of the bubbles was also counted, resulting in overpayment for fuel costs. To solve this, we introduced the smart sounding scale "Honesty." It does not react to bubbles, allowing for accurate measurement of the liquid level, and it reduced the conventional measurement time by approximately 75%. [Overview] ■ Case Study: Marine Fuel Tank ■ Challenge: Improving the efficiency of tank liquid level measurement operations and achieving accurate measurements ■ Proposed Product: Smart Sounding Scale "Honesty" - The sensor at the tip of the measuring device does not react to bubbles, accurately capturing the actual liquid level. - There are already over 1,000 units delivered, installed on more than 500 vessels. *For more details, please refer to the PDF document or feel free to contact us.

• Other measuring instruments

We would like to introduce a case that solved the problem of measuring the air pressure in a negative pressure compartment on a ship. There was a need to create a negative pressure compartment on the ship, but there were no sensors that could reliably measure indoor air pressure despite the ship's swaying and vibrations. As a result, we sought a pressure sensor that could provide stable signal output even in the marine environment, and we implemented it. It can output stable readings even in conditions of ship movement and vibration. 【Overview】 ■ Case: Indoor pressure monitoring in a ship's negative pressure compartment ■ Problem: Need to measure air pressure in a negative pressure compartment on the ship ■ Proposed product: High-precision pressure sensor ・Stable output even in conditions of ship movement and vibration ・By integrating the system, it is also possible to coordinate with other devices such as air conditioning fans *For more details, please refer to the PDF document or feel free to contact us.

• Other measuring instruments

This product is a flapper-type flow meter that does not require a power supply or other external sources. The opening degree of the flapper corresponds to the flow rate and is transmitted to the pointer via a magnet, continuously indicating the instantaneous flow rate. Additional contact signals can be added, and it can measure opaque liquids as well. 【Features】 ■ No power supply or external sources required ■ The opening degree of the flapper is transmitted to the pointer via a magnet according to the flow rate ■ Continuously indicates the instantaneous flow rate ■ Additional contact signals can be added ■ Can measure opaque liquids *For more details, please refer to the PDF document or feel free to contact us.

• Other measuring instruments

This product is a system designed to efficiently ensure the stable navigation and cargo handling of vessels. It remotely opens and closes valves to intake and discharge seawater in the ballast tank. When there is no cargo listed on the vessel, seawater is added to the ballast tank to lower the ship's center of gravity, creating a stable operating posture. During cargo loading, ballast water is discharged while cargo is being loaded. 【Features】 ■ Customizable according to customer specifications ■ Remote opening and closing of valves without manual operation ■ Real-time monitoring of the liquid level in the tank, allowing for valve operation accordingly *For more details, please refer to the related link page or feel free to contact us.

• others

Semco Co., Ltd. has established a significant track record as a measurement instrument manufacturer since its founding, being adopted by nearly all shipyards in Japan. Drawing from our experience in liquid level measurement in the harsh environment of shipbuilding, we are now also being adopted by companies in other industries such as power, environment, and food. If you have any concerns such as: "I am struggling with liquid level measurement in harsh environments" "I want to measure liquid levels while maintaining sanitary hygiene" Please feel free to contact us.

• Other measuring instruments

The float-type liquid level gauge "Fig.6000" is a float-type liquid level gauge that measures and manages liquid levels. A float floating on the liquid surface is directly connected to a display unit via a wire, allowing real-time display of the liquid level position. While it has already established a standard position in the maritime industry, it can flexibly accommodate various applications and installation conditions, making it suitable for a wide range of industrial fields. 【Features】 ■ Robust and easy to maintain due to its simple mechanical structure ■ No need for a power source or air source. Energy-efficient and economical ■ Compact size ■ Up to four electrical contacts can be installed. Easy to change or replace contact positions ■ Various installation methods reduce hazardous work and burden for the measurer ■ Capable of outputting analog signals (DC 4-20mA, 2-wire) Monitoring on-site or management via PC terminals is also possible. ■ Vertical ribbon type with tank height/capacity scale. ■ The installation position of the liquid level indicator is flexible, making plant design easier. ■ Equipped with a float operation confirmation device. *For more details, please download the PDF or feel free to contact us.

• Other measuring instruments

The 1/2 scale liquid level gauge with guide rail PCT (A) is a completely sealed liquid level gauge that does not allow air from the tank to escape to the outside. It detects the liquid level using a float that floats in the tank, and displays the liquid level through a weight directly connected to a wire. The liquid level is indicated using a balance weight connected to the float. Additionally, for tall tanks, a scale guide rail and scale board can be installed, allowing for placement in a visible position. ★ For heated tanks It prevents the accumulation of vapor, condensate, and mist inside the tank. 【Features】 ■ Completely sealed, preventing air from the tank from escaping to the outside ■ Uses a scaled scale board, allowing monitoring at eye level ■ The scale board is large and easy to see from a distance ■ No power source or air source required for operation High installation flexibility, energy-saving and economical ■ Contact installation is possible. Alarm and control settings can be configured *For more details, please download the PDF or feel free to contact us.

• Other measuring instruments

The "Direct-acting Float Type Liquid Level Gauge DF" is a type that indicates the liquid level with a float and shaft moving in a straight line. It is an eco-friendly type that does not require power sources such as electricity or air. In addition to liquid level display, it can also provide contact output. It has numerous achievements in power plants. 【Features】 ■ Float and shaft indicate liquid level in a straight line ■ Does not require power sources such as electricity or air ■ Capable of contact output in addition to liquid level display ■ Has numerous achievements in power plants *For more details, please refer to the external link page or feel free to contact us.

• Other measuring instruments

At Semco Co., Ltd., we handle "magnet float type liquid level gauges." As the float inside the metal tube moves up and down, the display section changes color in conjunction with the magnet attached to the float, allowing the liquid level to be checked from a distance. Additionally, our company has been involved in liquid level detection and control for many years. With the technology and know-how cultivated through experience, we aim to assist various customers in solving their challenges. *For more details, please refer to the external link page or feel free to contact us.

• Other measuring instruments

The liquid pressure in the tank is detected by a diaphragm, and the capacitance changes as the distance between the two parallel electrodes inside varies. An analog signal of 4-20 mA is also output from the center, transmitting and displaying the liquid level in the tank to monitoring panels and other devices. It is possible to provide not only the sensor but also a system that includes a display unit. <Features> ■ Compact size and robust structure make installation and maintenance easy. ■ The sensor part is protected, making the diaphragm less prone to damage. ■ Various mounting methods are available to accommodate different installation environments. *For more details, please refer to the PDF document or feel free to contact us.

• others

This product detects the liquid pressure in the tank using a diaphragm and transmits the pressure to the Bourdon tube inside the liquid level indicator through the enclosed liquid. It is a diaphragm-type liquid level gauge that can display the liquid level by rotating a gear. With a simple structure and compact size, it is easy to install. Additionally, the display position can be freely set, eliminating the need for wraps or other installations even in tall tanks, and it does not require a power source or air source, making it energy-efficient and economical. <Features> ■ Simple structure ■ Compact size ■ Easy installation ■ Energy-efficient and economical ■ No need for wraps or other designs even in tall tanks *For more details, please refer to the PDF document or feel free to contact us.

• Weighing scale

The "Air Purge Type Liquid Level Gauge" handled by Semco Co., Ltd. is a higher model of the air type liquid level gauge. It allows measurement with a minimal supply of air through computer control. Additionally, it can be used in hazardous areas. Our company has been involved in liquid level detection and control for many years. We aim to assist various customers in solving their challenges with the technology and know-how cultivated through our experience. 【Features】 ■ Measurement possible with a minimal supply of air ■ Usable in hazardous areas *For more details, please refer to the external link page or feel free to contact us.

• Other measuring instruments

The radar is emitted from the sensor unit, reflects off the surface of the measurement target, and returns to the sensor. The time taken from emission to reflection and return is measured, converted into distance, and output as a 4-20mA signal to display the liquid level. <Features> ■ Compact size for easy installation, achieving reduced construction time. ■ Equipped with an automatic adjustment function for ease of handling. ■ Easy maintenance with push-button calibration. *For more details, please refer to the PDF document or feel free to contact us.

• Other measuring instruments

Semco Co., Ltd. offers "glass liquid level gauges." You can directly check the liquid level inside the tank through the glass. Additionally, our company has been involved in liquid level detection and control for many years. With the technology and know-how cultivated through experience, we aim to assist various customers in solving their challenges. *For more details, please refer to the external link page or feel free to contact us.

• Other measuring instruments

"Honesty" is a sounding tape measure equipped with a liquid contact sensor at the tip of the traditional sounding tape, enabling a reduction in measurement time and accurate reading of the liquid level. When the sensor reaches the liquid surface, it notifies you with a line and a buzzer. The value on your tape measure at this time is the liquid level. 【Features】 ■ Can read the liquid level simultaneously with the contact of the tape measure tip ■ Does not react to bubbles, only responds to the actual liquid surface ■ Uses readily available dry batteries as power source ■ Approved by the Nippon Kaiji Kyokai (NK) ■ The tape measure uses fiberglass, which excels in flexibility and strength *For more details, please download the PDF or feel free to contact us.

• Other measuring instruments
• Foundation construction
• Ground foundation construction method

The "bar graph type indicator" is a liquid level gauge that moves up and down in response to an input analog signal, reflecting the current value. The input signals can include not only current values but also voltage, PT100, pulse signals, and the output signals can accommodate a variety of input and output signals such as current values and RS485. Additionally, our company has been involved in liquid level detection and control for many years. We aim to assist various customers in solving their challenges with the technology and know-how cultivated through our experience. 【Features】 ■ The bar of the indicator moves up and down according to the current value ■ Capable of handling a variety of input and output signals *For more details, please refer to the external link page or feel free to contact us.

• Other measuring instruments

This product is a float-type vertical level switch. It is commonly used in marine environments. Semco Co., Ltd. has been involved in liquid level detection and control for many years. We would like to assist various customers in solving their challenges with the technology and know-how cultivated through our experience. *For more details, please refer to the external link page or feel free to contact us.

• Other measuring instruments

This product is a horizontal level switch that is mounted from the side of the tank. It uses a high-capacity micro switch and is commonly used in marine environments. Semco Co., Ltd. has been involved in liquid level detection and control for many years. We would like to assist various customers in solving their challenges with the technology and know-how cultivated through our experience. *For more details, please refer to the external link page or feel free to contact us.

• Other measuring instruments

This product is a contact-type ultrasonic level switch. It can handle temperatures from -200 to 450°C. It accurately detects liquid levels even in high-viscosity liquids or when there are bubbles on the surface. Semco Co., Ltd. has been involved in liquid level detection and control for many years. With the technology and know-how cultivated through experience, we aim to assist various customers in solving their challenges. 【Features】 ■ Contact type ■ Temperature range from -200 to 450°C ■ Accurately detects liquid levels even in high-viscosity liquids or when there are bubbles on the surface *For more details, please refer to the external link page or feel free to contact us.

• Other measuring instruments

The "sight flow indicator" is a flapper-type flow meter. It has a simple structure and is easy to maintain. Our company has been involved in liquid level detection and control for many years. We would like to assist various customers in solving their challenges with the technology and know-how cultivated through our experience. *For more details, please refer to the external link page or feel free to contact us.

• Other measuring instruments

This product is an instrument for measuring the volume of fluid (gas, liquid, vapor) flowing through pipes and grooves per unit time. It transmits the opening degree of the flapper, which corresponds to the flow, to the pointer via a magnet, continuously displaying the instantaneous flow rate. Additionally, it allows for the addition of contact signals and can measure opaque liquids. <Features> ■ Continuous instantaneous flow rate display ■ Additional contact signals possible ■ Measurement of opaque liquids possible *For more details, please refer to the PDF document or feel free to contact us.

• Other measuring instruments

The "ultrasonic flow meter" handled by Semco Co., Ltd. allows for flow monitoring from the outside of the piping. Since no sensors are installed inside the piping, maintenance is easy. Calibration certificates can also be issued. Our company has been involved in liquid level detection and control for many years. With the technology and know-how cultivated through experience, we would like to assist various customers in solving their challenges. 【Features】 ■ Flow monitoring from the outside of the piping ■ No sensors installed inside the piping ■ Easy maintenance ■ Calibration certificate issuance available *For more details, please refer to the external link page or feel free to contact us.

• Other measuring instruments

If you have any questions regarding the introduction below, please feel free to contact us.

• Monitoring and Control Equipment

The product is designed to respond to incidents such as maritime accidents, where seawater floods the interior of the ship. The installed sensors react and send an alarm to the bridge. It is also equipped with a function to remotely drain the flooded seawater from the ship's interior to the exterior. After installation or during regular inspections, it can be easily tested with a handheld screwdriver without using air or water. Since it became mandatory under the SOLAS rules of the IMO (International Maritime Organization) in 2004, it has been adopted by numerous vessels. 【Features】 ■ No need for air sources or special tools; inspections after installation can be performed easily and quickly with commonly used tools. ■ Being float-type, the structure is simple. Even crew members with limited engineering knowledge can easily conduct inspections and maintenance. *For more details, please refer to the PDF materials or feel free to contact us.

• Other Management Services
• Drainage material
• Flood prevention facilities, fire tanks, and flood control ponds