In geotechnical engineering, hydraulic conductivity is a crucial characteristic that affects applications like stability analysis and irrigation management. However, clay soils usually have low hydraulic conductivity, which makes them unsuitable for use in several types of constructions. This current study investigates the combined use of glass powder and rice husk ash as additives and evaluates their impact on clay soil’s hydraulic conductivity. The research involved preparing soil specimens by mixing 10% glass powder with varying percentages of rice husk (2.5%, 5%, 7.5%, and 10%). Permeability testing was performed using the falling head method, following the Indonesian standard SNI 03-6870:2002. According to a grain size examination, more than 85% of soil’s small particles could be passed through a number 200 sieve. The result showed that adding glass powder and rice husk ash significantly increased the soil’s void ratio and hydraulic conductivity. With 10% glass powder and 5% rice husk ash added, the void ratio peaked at 0.633, and with 10% glass powder and 10% rice husk ash, the greatest hydraulic conductivity was 1.4973×10−3 m/day (1.7329×10− 5 cm/sec). However, only the specimen with 10% glass powder and 5% rice husk maintained hydraulic conductivity within the acceptable limit for liners and covers (≤ 1×10−7 cm/sec). The findings highlight the importance of optimizing stabilizer proportions to achieve desirable soil characteristics.