Groundwater Management Comparative Analysis

This paper compares groundwater management approaches in Tokyo, Japan and Orange County Water District (OCWD), U.S.A.

Excessive groundwater pumping is a growing global concern.1 Generally speaking, methods of managing natural resources such as groundwater can be classified into three categories: direct regulation, market approaches (such as taxes and tradable permits), and community-based approaches.2 Needless to say, each method cannot always be a perfect solution by itself. These methods are often implemented in combination with other supply-oriented policies such as artificial recharge and construction of waterworks for water supply treatment. Nevertheless, the classification above is a useful way to understand the variety of policy combinations among different regions.

This paper compares groundwater management approaches in Tokyo, Japan and Orange County Water District (OCWD), U.S.A.: the former is a general-purpose government that deals with many social problems including water supply, the latter is an ad-hoc government whose task is limited to managing local groundwater. The time period for comparison is the 1950s to the present.

Both areas have faced excessive groundwater pumping but their responses have been different. The main policy tools introduced in Tokyo were construction of waterworks to supply surface water and technological regulation, while in OCWD they were the imposition of a pump tax and artificial recharge based on the tax revenue. The results of the two policies were in sharp contrast: water supply was almost fully shifted from groundwater to surface water in Tokyo, whereas groundwater remained an important water source in OCWD.

Although the socioeconomic background, time of problem recognition, and initiation period of countermeasures were very similar in both areas, the practical solutions and results varied substantially. This paper looks at what caused this difference and assesses the advantages and disadvantages of each policy combination.

The difference in policy responses between the two areas was caused by three factors: subsidy systems, legal rules of groundwater pumping, and local governmental authority. In the case of Tokyo, the Industrial Water Law of 1956 introduced well diameter limitation and well depth control which made it prohibitively expensive to dig a new well in Tokyo. At the same time, the law enabled the national government to give financial support to the construction of industrial waterworks to lower the price of surface water. This combination promoted the conversion of water supply from groundwater to surface water.

On the other hand, no subsidy was available from the county, state, or federal governments in the case of OCWD. Therefore, OCWD had no choice but to secure a budget for groundwater management by itself and this led to establishment of the pump tax in 1954. If OCWD had attempted to build an aqueduct to import water by itself, it would have been very costly, and it would have been very difficult to lower water prices without a subsidy from higher-level governments. The groundwater basin in Orange County is mainly recharged by the natural flow of the Santa Ana River, and it avoids the cost of constructing infrastructure to store and deliver water to end users.

It is difficult to introduce a pump tax system in Japan because of the legal definition of groundwater. Groundwater in the country is regarded as a part of land ownership, and therefore public control of its use is very weak. The definition was first established by a judgment of the Supreme Court in 18963 and strengthened by civil law that was enacted one month later. Both admitted a landowner’s discretion to use groundwater beneath that land. As a result, regulation of groundwater has often been regarded as an infringement of land ownership.

One of the basic rules for groundwater use in California is called the reasonable use doctrine. Although it prohibits export of groundwater outside the overlying land, it admits wide discretion of the landowner. 4 In this sense, the rule is similar to that in Japan. Nonetheless, a pump tax was introduced only in OCWD. This is because the district authority was defined more clearly than in the case of Tokyo. First of all, OCWD was established with the approval of the state legislature in 1933. Additionally, the pump tax authorization was given to OCWD by the same organization in 1954. Such authorization was not given in Tokyo.

Countermeasures taken in Tokyo and OCWD have both advantages and disadvantages. The countermeasures in Tokyo worked well to stop land subsidence, but they also provoked unexpected byproducts such as unused groundwater and a chronic deficit of industrial waterworks. The countermeasures in OCWD can be evaluated positively in terms of diversification of water sources and it satisfies the polluter-pays principle to some extent. Moreover, OCWD makes maximum use of local ecosystem services. However, the pump tax does not reduce groundwater demand because the tax rate is set lower than the price of imported water.

Based on these two case studies the following policy lessons can be deduced. First, neither technological regulation nor a pump tax provides a perfect solution without conditions. Second, although there are many possible policy options for groundwater management, availability is limited by legal and social factors. Third, complete conversion of water supply may cause a problem of a too-high groundwater level.

Although such groundwater problems are of worldwide concern, it is in a local area such as a watershed that practical solutions are taken. These solutions vary depending on the political, economic, and social backgrounds of each area. This paper addressed two kinds of policy combinations, revealing advantages and disadvantages of each set. Nevertheless, the policy choice for groundwater management is not limited to those addressed herein. For example, a tradable permit system could also be considered. Much information should be collected through case studies to promote appropriate policy-making at the local level. This paper is a first step toward such integrated research.

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Taxonomy

• Groundwater
• Data Management
• Analysis & Visualization
• Computational Fluid Dynamics
• Groundwater Assessment
• Groundwater Modeling
• Groundwater Prospecting
• Groundwater Mapping
• Surface-Groundwater Interaction
• Groundwater Surveys and Development