Northern Thames Basin

The Northern Thames Basin is a National Character Area (NCA) as designated by Natural England. It is a diverse area, extending from Hertfordshire in the west to the Essex coast in the east. It is separated from the North Sea and Thames Estuary by a separate NCA, the Greater Thames Estuary. The Northern Thames Basin contains the suburbs of North London, historic towns and cities such as St Albans and Colchester, and new towns such as Welwyn Garden City, Hatfield and Basildon.

The topography is varied, with a wide plateau divided by river valleys. The prominent hills and ridges of the Bagshot Hills are notable to the northwest, and flat land is found in the south. A layer of thick clay, the London Clay, produces heavy, acidic soils. Therefore, much ancient woodland has been retained. Hertfordshire is heavily wooded in some areas as are parts of Essex. Glacial sands and gravels have resulted in nutrient-poor which support small areas of remnant lowland heathlands. There are alluvial deposits which produce well drained and fertile soils. The underlying chalk beds are a main source of recharge for the principal London Basin Chalk aquifer. There are broad valleys containing the major rivers Ver, Colne and Lea, and slightly steeper valleys containing other rivers.

Principal summits Although a low-lying area, the clay gives rise to a number of separate low hills. The following hills within the NCA have at least 30 metres of topographic prominence:https://www.hill-bagging.co.uk/

HillElevationProminenceGrid referenceBushey Heath153.4 m (503 ft)80 mTQ151939Deacons Hill147.6 m (485 ft)30.6 mTQ183949Highwood Hill143.9 m (472 ft)31.2 mTQ218941Sandy Lane135 m (443 ft)62 mTQ105919Shenley Hill134 m (440 ft)32 mTL190006Burnham Green126.4 m (415 ft)32 mTL264165Harrow on the Hill124 m (407 ft)71 mTQ153874Brentwood Park120.9 m (397 ft)57 mTQ590913Langdon Hill118 m (387 ft)81 mTQ679865Epping Forest117.2 m (385 ft)38 mTL435003Danbury Ring111 m (364 ft)63 mTL779051Havering atte Bower107 m (351 ft)38 mTQ516930Lambourne Hill102 m (335 ft)39 mTQ478951Bell Hill98.9 m (324 ft)33.8 mTQ674939Wakemans Hill92 m (302 ft)40 mTQ207889Criers Wood89 m (292 ft)50 mTL857132Barn Hill86 m (282 ft)32 mTQ193873Horsenden Hill84.9 m (279 ft)32 mTQ161843Thundersley Hill84.5 m (277 ft)66 mTQ790880Wembley Hill72 m (236 ft)33 mTQ186855Hanger Hill65 m (213 ft)33 mTQ187820Stamfords Hill52.8 m (173 ft)33 mTQ892986Sandy Lane Pit47.2 m (155 ft)30.1 mTQ557809

References