Open-top tank: Whether this option can be used depends on the type of water supply planned. Below is a detailed response, including the case studies and requirements listed in the reference text.
Table of Contents
When Is an Open-Top Tank Permitted?
An open-top water storage tank may be installed only in presence of a single water supply.
This point is crucial because it directly links the “constructive”/design choice of the (open-air) water reservoir to the type of water supply system being used. In practice, before discussing the details of the reservoir, it is necessary to verify and clearly state what type of water supply system is being implemented.
When It Is Prohibited: The Case of a Single Upper Water Supply Line
This same approach also leads to a prohibition: open-air water reservoirs are prohibited whena single, larger water supply system is to be constructed.
Therefore, if the project or conditions require a single, higher-category water supply, the “open-air” configuration is not among the permissible options. The practical consequence is that verifying the type of water supply (single vs. single-upper) becomes a key “turning point” in the design process: if the category changes, so does what is permitted for the tank.
Planned Water Supplies: An Overview to Help You Choose
The text refers to the planned water supplies and some of their characteristics. The list includes:
- Individual Water Supplies
- Upper Single Water Inlets
- Dual water supplies
- Combined Water Supplies
For the purposes of this application (open-top tank), the two key categories are the first two: single (where the solution is permissible) and upper single (where it is prohibited). The other two categories (double and combined) are listed, but they are not described in detail in the text available here; for this reason, when the goal is to “select the reservoir,” it is best to first determine precisely which of the four categories is being used.
Focus: Upper Individual Water Inlets (and Why They Affect the Reservoir)
Upper-tier single water supplies are defined as those single water supplies that provide a high degree of reliability.
The text provides examples of the following types of individual water supply systems:
- An aqueduct fed from both ends
- A gravity-fed tank without a pump
- A tank with TWO or more pumps
- An inexhaustible source with TWO or more pumps
The connection to the initial question is direct: if your case falls under the “upper single” category, then the water reservoir cannot be an open-air one. It is therefore essential not to confuse:
- the presence of a tank (which may also appear in the “upper single”), with
- the feasibility of the “open-air” solution (which is, in fact, ruled out specifically when referring to a single upper level).
Tank Requirements in Certain Configurations (Gravity-Fed or Storage with 2 or More Pumps)
The text specifies that, in the case of a gravity-fed or storage tank with two or more pumps, the tank must meet the following conditions:
- It must be at least equal to the total capacity required by the project
- It must not allow light and/or foreign matter to penetrate it
- Drinking water must be used
- It must be painted and protected against corrosion (minimal maintenance required after 10 years)
These requirements have practical implications: regardless of the solution adopted, the water reserve should not be treated as “just any volume of water,” but as a component subject to clear constraints (capacity, protection, water quality, corrosion protection).
Consistency note to be verified: The phrase“open-air”and the requirementthat “it must not allow light to penetrate”may give rise to interpretive doubts; it is advisable to clarify exactly what is meant by “open-air” in this specific case (see the final section, “Missing Data / Questions”).
Practical Checks: What to Verify in the Project and During Document Review
To correctly apply the rule “allowed only with a single space / prohibited with a single space at the beginning,” it’s a good idea in practice to create a short checklist of documents:
- Specify the type of water supply (single, single upper, double, combined).
- If you are evaluating an open-top tank, confirm that it is connected to a single water supply.
- If the situation requires or involves a single, higher-level water supply, do not use an open-air solution.
- If the tank is a gravity-fed or storage tank with two or more pumps, check the following conditions one by one (design capacity, absence of light penetration or foreign material, potable water, paint coating, and corrosion protection).
Conclusion
An open-top tank is permitted only in presence of a single water supply; it is prohibited, however, whena single water supply of a higher capacity is installed. If the tank is a gravity-fed or storage tank with two or more pumps, the listed requirements (capacity, protective measures, potable water, corrosion protection) must also be met.
