On the basis of water quality problems associated with nutrients and sediments, Centennial Lake in the Little Patuxent River watershed (02-13-11-05) was identified on Marylands 1998 list as being impaired. This document establishes Total Maximum Daily Loads (TMDLs) for the nutrient phosphorus and sediments entering Centennial Lake. Centennial Lake is an impoundment located near Columbia in Howard County, Maryland. The impoundment lies on a tributary of the Little Patuxent River, which is in turn a tributary of the Patuxent River. The Little Patuxent River lies in the Patuxent River Drainage Basin, in Central Maryland. Centennial Lake was constructed for flood control and recreation. Centennial Lake is impacted by a high sediment load. The lake also experiences occasional nuisance seasonal algal blooms, due to over-enrichment by nutrients, interfering with recreational uses. The death and decay of excessive algae can cause violations of the water quality standard for dissolved oxygen (DO), resulting in a disruption of the lakes ecosystem balance and fish kills. Analysis suggests that phosphorus is the limiting nutrient for the production of algae in Centennial Lake. Due to the propensity of phosphorus to bind to sediments, the overall strategy is to simultaneously address the water quality problems associated with phosphorus and sediments. The water quality goal of these TMDLs is to reduce long-term phosphorus and sediment loads to acceptable levels consistent with the physical characteristics of Centennial Lake. The reduced phosphorus loading rate is predicted to resolve excess algae problems and maintain a dissolved oxygen concentration above the State water quality standard. The TMDL for phosphorus was determined using an empirical method known as the Vollenweider Relationship. Because the reduction of sediments is a component of controlling external phosphorus loads, a sediment loading rate consistent with narrative water quality criteria is predicted to be achieved. The average annual TMDL for phosphorus is about 664 lbs/yr. There are no point sources in the Centennial Lake basin. Consequently, the allocation is partitioned between nonpoint sources and the margin of safety. For sediments, the TMDL is established to achieve a reasonable loading rate predicted to occur as a result of the proposed control of phosphorus. This loading rate is estimated to result in preserving about 20 - 69% of the lakes design volume over a period of 100 years. Preliminary estimations.