Harris County Improvement District No. 21, Assessments; Liens for Assessments. (d) The board may make a correction to or deletion from the assessment roll that does not increase the amount of assessment of any parcel of land without providing notice and holding a hearing in the manner required for additional assessments. Added by Acts 2009, 81st Leg., R.S., Ch. 1101 (H.B. 4828), Sec. 1, eff. June 19, 2009.