A city-wide wireless sewer sensor network can be made intelligent by having parasitic slot array manhole cover antennas. The utilization of parasitic antennas is explored to demonstrate the effect of limited beam scanning on a real sensor network system. The combination of an electronically steerable beamforming capability and an angular diversity technique in this antenna allowed the antenna to adapt to its radio environment and find optimal receive characteristics. The sensor measurement result indicates that the intelligence of the antenna significantly improves packet reception rate and received signal strength indication (RSSI). We improved by 64% in packet rate and 10 dB in RSSI, compared to a uniformly radiating dipole antenna.