Although gel treatments have gained acceptance for injection well profile modification, high treatment cost and potential loss of low permeability zone injectivity curbs implementation. This study investigates an in-situ generated foamed gel barrier that is well suited for long-term waterflood diversion because it provides an intermediate degree of plugging, yet requires substantially less polymer than bulk gels. Microvisual observations indicate foamed gel barriers are initially impermeable but break down when the pressure exceeds a critical value. This critical pressure that initiates breakdown varies with foam quality, permeability, and gel properties.