Artificial lakes were made in earlier times in order to save rainwater.

Explanation:
1. **Importance of water conservation**: Water is a precious natural resource that is vital for the survival of all living organisms. It is essential for various activities like drinking, agriculture, industries, etc. Hence, it is crucial to conserve water to meet the growing demands and ensure its availability for future generations.

2. **Rainwater as a source**: Rainwater is one of the primary sources of freshwater. It is collected from rainfall and can be used for various purposes. However, rainwater is often wasted as it runs off the surface and does not get adequately absorbed into the ground.

3. **Creating artificial lakes**: To address this issue, artificial lakes were created in earlier times. These lakes were designed to collect and store rainwater for later use. They were typically constructed by building dams or reservoirs in suitable locations.

4. **Collection of rainwater**: When it rains, the water falling on the surrounding catchment area gets collected in the artificial lake. The catchment area comprises the land surface that drains into the lake. As the water flows downhill, it gets stored in the lake, preventing it from being lost or wasted.

5. **Water storage**: The artificial lakes serve as large storage reservoirs for rainwater. By creating these lakes, the excess rainwater can be stored during periods of heavy rainfall and used during times of water scarcity or drought. This helps in maintaining a steady supply of water throughout the year.

6. **Benefits of artificial lakes**: Creating artificial lakes for rainwater storage offers several benefits, including:
- Conservation of water resources: By capturing rainwater, artificial lakes help in conserving water and reducing wastage.
- Recharge of groundwater: As the artificial lake collects rainwater, it slowly percolates into the ground, replenishing the groundwater table.
- Irrigation and agriculture: The stored rainwater can be used for irrigation purposes, supporting agricultural activities and increasing crop yields.
- Drinking water supply: In areas where access to freshwater is limited, artificial lakes can provide a source of drinking water for nearby communities.

In conclusion, artificial lakes were made in earlier times to save rainwater, as it is a valuable source of freshwater. These lakes helped in conserving water resources, replenishing groundwater, and providing water for various uses such as irrigation and drinking.